All for test 2

Gram-negative flagella have ___ rings in the basal body. They are attached to the ___. (2)

4 rings (two pairs) cytoplasmic membrane and cell wall

What are the monomers of DNA? (2)

4 triphosphate deoxyribonucleotides - each composed of a base, deoxyribose sugar, and three phosphate groups

What is the function of the CD8 receptor? - Bind to MHC molecules - Activate cytokines - Produce gamma interferon - Produce IL-2

Bind to MHC molecules

Vector Transmission

Biological vectors - Transmit pathogens and serve as host for some stage of the pathogen's life cycle - Biting arthropods transmit many diseases to humans. - EX: flea, tick, mosquito Mechanical vectors - Passively transmit pathogens present on their body to new hosts - EX: houseflies and cockroaches (Salmonella and Shigella)

Figure 1.6 - Which protozoa uses cilia?

Blepharisma americana

The skin and the mucous membranes are similar in which of the following aspects? - Both have multiple layers of epidermal cells. - Both have an outer layer of dead cells. - Both have epithelial cells packed closely together. - Both produce mucus.

Both have epithelial cells packed closely together. - The epidermal cells in the skin may be arranged in several layers, while the epidermis in some mucous membranes is only one-cell thick, but in both cases the cells are tightly packed.

4 Chemicals that can trigger/promote blood vessel dilation

Bradykinin - powerful vasodilator peptide - forms when blood clotting follows damage to a BV --> triggers a plasma protein to convert into a peptide - cause VD of arterioles Prostaglandin - released by patrolling macrophages - use TLRs and NOD proteinsn to ID invaders Leukotrienes - released by patrolling macrophages Histamine - released by basophils, platelets, and mast cells when they're exposed to either Complement fragment C3a or C5a - cause VD of arterioles

Who invented the smallpox vaccine? What else about it is important?

British MD, Edward Jenner (1796) - This was the world's first immunization

How can you identify the oxygen requirement of an organism?

By growing it in a medium (thioglycollate) that contains an oxygen gradient from top to bottom!

A reducing media is used to culture A. Fastidious organisms B. Aerobic organisms C. Anaerobic organisms D. Any pathogenic organisms E. None of the choices are correct

C. Anaerobic organisms

How is disinfection and sanitation different?

Depends on the place of activity. Disinfection is private, at home for personal use. Disinfect your dishes at home. Sanitation is public, for the public use. Sanitize dishes at a restaurant.

Contact Transmission (7)

Direct contact transmission - Usually involves body contact between hosts - Transmission within a single individual can also occur Indirect contact transmission - Pathogens are spread from host to host by fomites (non-living objects) Droplet transmission - Spread of pathogens in droplet sof mucus by exhaling, coughing, and sneezing

Membrane Filtration - direct method requiring incubation (4)

Direct method of estimating pop. size in which a large sample is poured through a filter small enough to trap cells. - membrane is transferred onto a solid medium and the colonies present after incubation are counted - the # of colonies is equal to the number of CFUs in the original large sample - used when microbe population is very small

How do fungi differ from plants?

Fungi obtain their food from other organisms (rather than making it themselves)

Which of the following statements concerning genetic mutations is FALSE? - A mutation is any change in the nucleotide base sequence of an organism's genome. - Some mutations cause no change in phenotype. - Gene mutations always result in problems for cells and organisms. - Mutations in asexual organisms are usually passed on to the offspring.

Gene mutations always result in problems for cells and organisms.

How is generalized transduction different from specialized transduction? - Specialized transduction uses animal viruses instead of bacteriophage. - Only one specific host gene is transferred in both specialized transduction and generalized transduction. - Generalized transduction is initiated by a lysogenic bacteriophage; specialized transduction is initiated by a lytic phage. - Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage.

Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage.

How does alteration of nucleic acids cause mutation?

Genes are composed of nucleic acid!

3 Basic Viral Shapes - differences in viruses

Helical - spiral fashion Polyhedral - roughly spherical, similar to geodesic dome - Icosahedron (20 sides) is most common Complex - many more than don't fit into either previous categories

* Review - What are the 6 enzymes used in DNA replication?

Helicase - unzips double helix, breaking H bonds DNA Polymerase I - replaces RNA Primers with DNA DNA Polymerase III - forms the bond (between 3 ' OH of existing strand to 4 ' P of incoming nucleotide) - proofreads DNA Gyrase - relieves tension in DNA while it's being unwound Primase - binds to origin; lays down RNA primer DNA Ligase - connects gaps between Okazaki fragments; forms the bond between 3' and 5' ends

H. pylori (3)

Helicobacter pylori - acid-tolerant bacterium that neutralizes stomach acid - the cause of most gastric ulcers

What is the role of helper T cells in the adaptive immune response? - Helper T cells produce and secrete antibodies. - Helper T cells phagocytize bacteria and viruses. - Helper T cells directly kill infected host cells. - Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells.

Helper T cells activate B cells that are displaying antigen, causing clonal expansion. Helper T cells also activate cytotoxic T cells, which will search for and destroy infected host cells.

Immune cells that secrete cytokines and activate other immune cells are: - Cytotoxic T-cells - Invading pathogenic bacteria - Virally infected cells - Helper T-cells - Abnormal body cells

Helper T-cells

When is denaturation considered reversible?

If the denatured enzyme's non-covalent bonds reform on the return of normal conditions

anaerobic respiration

Respiration that does not require oxygen (produces lactic acid)

aerobic respiration

Respiration that requires oxygen

Most nucleoid don't have a surrounding membrane. T/F

True! BUT a distinct boundary can be seen between Nucleoid and Cytoplasm

Organisms may not exhibit all 4 processes of life at all times. T/F

True! ex. Reproduction may be postponed or curtailed by age, disease, or choice (humans)

The bases of nucleotides hydrogen-bond to one another in specific ways. T/F

True! it's called Complementary Base Pairs (bp)

What forms the peptide part of peptidoglycan? (2)

amino acid polypeptide chains - the AAs differ among bacterial species

Hfr cells are associated with which of the following? - transduction - transformation - transposons - conjugation

conjugation

Eukaryotic

eukaryotic cells contain a nucleus composed of genetic material surrounded by a distinct membrane

___ involves a change in gene frequency in a population.

evolution

Disruption of Normal Microbiota - Side Effects of Drugs (5)

ex. long-term use of broad-spectrum antibacterials - May result in secondary infections from transient pathogens - Overgrowth of normal flora causes superinfections - Of greatest concern for hospitalized patients --> They're typically exposed to pathogens with resistance

Toxins and bacterial parts are considered _____ antigen because they are present outside of the body's cells. - exogenous - endogenous - epitopes - autoantigen

exogenous - Exogenous antigen is present outside of our body's cells and become internalized during processing

what bacteria produce endospores?

gram-positive bacillus and clostridium

G + C (3)

guanine + cytosine - formed by 3 Hydrogen bonds - found in both DNA & RNA

Each bacterial cell has a single copy of the genome and is therefore called a ___ cell.

haploid cell

Avirulent

harmless

HAI

healthcare-associated infections

Why are enveloped viruses more fragile than naked viruses?

membranes are more susceptible to detergents, alcohol, and drying out

transposase

recognizes its own inverted repeat in a target site, cuts the DNA at that site, and inserts the transposon

How are bacterial and archaeal taxa recognized? (3)

similarities in - RNA - DNA - protein sequences

Burst Time

the time required for lytic reproduction (from attachment to release)

Decimal Reduction Time

the time required to destroy 90% of the microbes in a sample

substrate-level phosphorylation

the transfer of phosphate to ADP from another phosphorylated organic compound

4 Types of RNA Viruses of Animals

+ssRNA -ssRA dsRNA Retroviruses

Histones

- stabilize and package DNA to form Nucleosomes connected by linker DNA

What is an example of an inducible operon?

lactose (lac) operon

Cysts of Protozoa - resistance (3)

- cyst wall prevents entry of most disinfectants - protects against drying - shields against heat/radiation

Prion disease can be ___, ____, or ____.

- inherited - sporadic - infectious

3 DNA Repair Enzymes

- light-repair enzymes (photolyases) - excision-repair enzymes - mismatch-repair enzymes

Lysis Stage - glycolysis (2)

- Break the 6-carbon glucose molecule into 2 3-carbon sugar molecules - Frcutose 1,6-biphosphate becomes two glyceralhyde 3-phosphate

taxonomic system (3)

"a system for naming plants and animals and grouping similar organisms together" - developed by Swedist botanist Carolus Linnaeus (1707-1778) - at the time, grouped all organisms into either the Animal or Plant kingdom

What did Leeuwenhoek sometimes call microbes?

"beasties" He also called single-celled protozoa "animalcules"

* Where does DNA replication begin?

"origin" - a specific sequence of nucleotides

When the flagellum rotates counterclockwise, the bacterium ___ in a ___ ___.

"runs" in a single direction

When the flagellum rotates clockwise, the bacterium ___ and ___ ___.

"tumbles" and changes direction

Calculate Mutation Rate

(((# of colonies seen with use of mutagen) - (# of colonies seen without use of mutagen)) / (# of colonies seen without use of mutagen)) x 100% (((5 mutant colonies seen after mutagen introduced - (1 mutant colony seen before mutagen introduced)) / (1 mutant colony seen before mutagen introduced)) x 100% = 4 x 100% = 400% mutation rate

Paul Ehrlich (4)

(1854 - 1915) - coined "chemotherapy" to describe chemicals that selectively kill pathogens while barely affecting patient - "magic bullets" bind to germ receptors and kill them; host cells lack receptor molecules and are ignored - discovered Arsenic compounds that work against syphilis - toxic to humans

Alexander Fleming (2)

(1881 - 1955) - discovered Penicillin is released from Penicillium mold (in 1928) - not enough stock available until 1940s

Selman Waksman (2)

(1888 - 1973) - discovered Streptomyces are sources of useful antimicrobials - coined "antibiotics"

Gerhard Domagk (2)

(1895 - 1964) - discovered sulfanilamide (in 1932) - The FIRST practical antimicrobial

*** How many NADH and FADH2 are produced during glucose catabolism?

(2 from glycolysis, 2 from acetyl-CoA synthesis, 6 from Kreb's) 10 NADH (from Kreb's cycle) 2 FADH2

List Most Resistant to Least Resistant Microbes (13)

(MOST RESISTANT) 1. Prions 2. Bacterial endospores 3. Cysts of Cryptosporidium (protozoan) 4. Mycobacteria 5. Cysts of other protozoa 6. Small, nonenveloped viruses 7. Active-stage protozoa (trophozoites) 8. Fungal spores 9. Most Gram-negative bacteria 10. Vegetative fungi 11. Large, nonenveloped bacteria 12. Most Gram-positive bacteria 13. Enveloped viruses (HIV) (MOST SUSCEPTIBLE)

What shapes are these viral examples? (photo)

(a) Tobacco Mosaic Virus (b) Rhinovirus (common cold) (c) Megavirus (d) Rabies virus

Viral Shape Answers (4)

(a) Tobacco Mosaic Virus - helical (b) Rhinovirus (common cold) - polyhedral (c) Megavirus - complex (d) Rabies virus - complex

Kreb's Cycle Results in: (4)

(total sum of each of the two acetyl-CoA) - 2 ATP - 2 FADH2 - 6 NADH - 4 CO2

Refrigeration- 3 ways to preserve cultures (2)

4 C (39 F) - stores for short periods of time

The opposite end of a DNA strand (to a 5 ' end) is called a ____

3 ' end - it terminates with a hydroxyl group bound to a 3 ' carbon of deoxyribose

Entry/Uncoating of Animal Viruses

3 difference mechanisms: 1. Direct Penetration 2. Membrane Fusion 3. Endocytosis

3 tRNA binding sites on smaller subunit of ribosome

*each site is named for its function A site - accommodates a tRNA delivering an amino acid P site - accommodates a tRNA and the growing polypeptide E site - discharged tRNAs exit from here

-ssRNA viruses of animals

+ssRNA strand must be synthesized by RNA-dependent RNA polymerase to make proteins - Negative-sense ssRNA virus: transcription forms +ssRNA to serve both as mRNA and as template for viral −ssRNA genome

Lymphocytes - 3rd Line of Defense (6)

- "Adaptive Immunity" - SPECIFIC - HAVE MEMORY --> alter the body's defenses such that they act more effectively upon subsequent infection by that same specific strain (adaptive immunity is what makes vaccines work) --> must be activated by antigen-presenting cells before defense can launch - Ex. antibodies, cytotoxic cells

Prevention of Virus Attachment - 6/6 Mechanisms of Microbial Drug Action

- "Attachment antagonists" block viral attachment or receptor proteins - New area of antimicrobial drug development

Opsonization - Antibody Function (5)

- "Changing the surface of an antigen so as to enhance phagocytosis" - Antibodies act as opsonins—molecules that stimulate phagocytosis - Neutrophils and macrophages have receptors for the stems of IgG molecules --> these leukocytes bind to the stems of antibodies --> Once antibodies are so bound, the leukocytes phagocytize them, along with the antigens they carry, at a faster rate compared to antigens lacking bound antibody

Agglutination - Antibody Function (4)

- "Numerous antibodies can aggregate antigens together" - each basic antibody has two antigen- binding sites, each can attach to two epitopes at once - Agglutination of soluble molecules typically causes them to become insoluble and precipitate - Agglutination may hinder the activity of pathogenic organisms and increases the chance that they will be phagocytized or filtered out of the blood by the spleen

Phagocytosis (5)

- "cell eating" - phagocytosis is executed by phagocytes; rid the body of pathogens that have evaded the body's first line of defense - not completely understood - 5 phagocytes - can be divided into 6 stages

Germ Theory of Disease (3)

- "disease is caused by infections of pathogenic microorganisms" - Koch's Postulates --> "To prove that a given infectious agent causes a given disease, a scientist must satisfy all of Koch's postulates"

Transposons (5)

- "jumping genes" - segments of DNA, 700 to 40,000 bp in length, that transpose (move) themselves from one location in a DNA molecule to another location in the same or a different molecule - can replicate while moving - can move onto plasmids and be transferred into another cell - all contain palindromic sequences at the end

Surfactants - Antimicrobial Chemicals (6)

- "surface active" chemical; reduces surface tension, making solvent (water) more effective at dissolving solutes - ex. Soaps and detergents - low activity - Quaternary ammonium compounds (quats) --> Ammonium cation (NH4+) disrupts cellular membranes --> tasteless, odorless, harmless

Spectrum of Action (2) - Type of Pathogen Antimicrobials Are Effective Against

- "the number of different kinds of pathogens a drug acts against" - Narrow vs. Broad spectrum

Radiation - Physical Methods of Microbial Control (2)

- "the release of high-speed subatomic particles or waves of electromagnetic energy from atoms" - 2 types: Particulate and Electromagnetic

Minimum Inhibitory Concentration (MIC) (2)

- "the smallest amount of the drug that will inhibit growth and reproduction of the pathogen" - can be determined via a Broth Dilution Test

Symbiosis

- "to live together" - 4 types (mutualism, commensalism, amensalism, parasitism)

The 10 Toll-like Receptors (picture) (4)

- 10 TLRs are known for humans - 1, 2, 4, 5, 6 are in cytoplasmic membranes - 3, 7, 8, 9 are added to phagosome membranes - some act alone, some act in pairs to recognize PAMPs

Specificity of the T Cell Receptor (TCR) (5)

- 10 different kinds - TCR binds only one unique epitope - TCRs do not recognize epitopes directly - TCRs only bind epitopes associated with a MHC protein - TCRs act primarily against cells that harbor intracellular pathogens or abnormal body cells

Ultra-high-temperature pasteurization (2)

- 135ºC for 1 sec, then rapid cooling - adversely affects taste!

Ultra-high-temperature sterilization (UHT) (4)

- 140ºC for 1-3 sec, then rapid cooling (through superheated steam) - Treated liquids can be stored indefinitely at room temperature - chemical degradation after months results in taste change - ex. dairy creamer at restaurants!!

review- Traditional EMP glycolysis produces: (3)

- 2 AT - 2 Pyruvate - 2 NADH per glucose oxidized

Complex transposons (2)

- 2 insertion sequences with another DNA sequence in between them that can't move on its own --> genes not connected with transposition; often gives selective advantage (ex. antibiotic resistance) and helps the transposon be copies when the cell is able to reproduce more

Azoles and Allylamines (6)

- 2 more antifungals/antiprotozoans that disrupt cyto-membranes - inhibit synthesis of ergosterol --> fungal cell membranes can't remain intact without it and lyse - generally harmless to humans because we don't manufacture ergosterol - ex. Fluconazole (azole) - ex. Terbinafine (allylamine)

Initiation - first stage of bacterial translation (5)

- 2 ribosomal subunits, mRNA, several protein factors and tRNA^fMET form an initiation complex - initiation in prokaryotes may occur while transcription occurs 1. the smaller ribosomal subunit attaches to mRNA at Shine-Dalgarno sequence to position AUG at ribosome's P Site 2. tRNA^fMET attaches to P site (UAC complements to AUG) 3. larger ribo. subunit attaches to form a complete initiation complex

Cytoplasm of Archaea (4)

- 70S ribosomes (like bacteria BUT they're different) - fibrous cytoskeleton - circular DNA in nucleoid (in cytosol) - lack membranous organelles

Eukaryotic Ribosomes

- 80S ribosomes (composed of 60S and 40S subunits) 60S -5S rRNA -5.8S rRNA -28S rRNA - 49 polypeptides 40S -18S rRNA - >33 polypeptides - REFERS ONLY TO RIBOSOMES IN THE CYTOSOL AND ROUGH ENDOPLASMIC RETICULUM

Chemokines (2)

- an immune system cytokine that signals leukocytes to rush to the site of inflammation or infection and activate other leukocytes - released by leukocytes already at the site of infection

ssDNA viruses of animals (4)

- A human virus with a genome composed of single-stranded DNA (ssDNA) is a parvovirus - Cells do not use ssDNA - ssDNA strand folds back on itself to form dsDNA, which is replicated by cellular DNA polymerase - new strand is released as ssDNA

Biofilm (6)

- A surface-coating colony of one or more species of prokaryotes that engage in metabolic cooperation (quizlet suggestion) - aggregates of many bacteria living together on a surface (text definition) - involved in about 2/3 of bacterial human infections - provide protection that free-floating bacteria lack ex. oral bacteria colonize teeth as dental plaque ex. lower concentrations of O2 in biofilms thwart effectiveness of some antibiotics

Retrovirus (5)

- A type of +ssRNA, but they do not use their genome as mRNA - Instead, retroviruses use a DNA intermediary that is transcribed from +RNA by reverse transcriptase carried within the capsid - The DNA intermediary then serves as the template for the synthesis of additional +ssRNA, which acts as both mRNA and as genomes for new virions - The DNA genome is incorporated into host chromosome via the enzyme integrase. - +ssRNA → dsDNA → +ssRNA → protein

Some Latent Animal Viruses (4)

- AIDS - chicken pox - hepatitis B - herpes viruses

Superbugs (3)

- AKA "Multiple-drug-resistant pathogens" - Resistant to most of the antibiotics and other medications commonly used to treat the infections they cause - Staphylococcus, Streptococcus, Enterococcus, Pseudomonas, Mycobacterium tuberculosis, Neisseria

* Pure cultures (4)

- AKA "axenic" - cultures composed of cells arising from a single progenitor (ancestor) or group of related cells - progenitor is termed a colony-forming unit (CFU) - aseptic techniques (sterilizing) prevents contamination or sterile substances or objects

Phenols - Antimicrobial Chemicals (7)

- AKA "carbolic acid" - antiseptic/disinfectant; intermediate/low activity - denature proteins / disrupt cell membrane - effective in presence of organic matter - remain active for prolonged time - bad odor and possible side effects (skin irritant; brain damage in infants) - common in healthcare, labs, home

palindrome in genetics (3)

- AKA "inverted repeat (IR)" - a region of DNA in which the sequence of nucleotides is identical to an inverted sequence in the complementary strand ex. GAATTC is the palindrome of CTTAAG

microRNA - regulation of transcription (5)

- AKA "miRNAs" - USED BY EUKARYOTES - single-strand RNA molecules about 22 bases long - binds with regulatory proteins to form miRNA-induced silencing complex (miRISC) - miRISC binds to complementary mRNA to prevent translation

Oxidation-reduction reaction (6)

- AKA "redox reaction" - Any metabolic reaction involving the transfer of electrons from an electron donor to an electron acceptor. Reactions in which electrons are accepted are called reduction reactions, whereas reactions in which electrons are donated are oxidation reactions. - an electron acceptor is said to be reduced (greater negative charge) - an electron donor is said to be oxidized (because their electrons are often donated to oxygen atoms) - OIL RIG (oxidation involves loss; reduction involves gain) - these reactions always occur simultaneously

Killing / Phagolysosome - 5th Stage of Phagocytosis (6)

- AKA "residual body" - contain antimicrobial substances (ex. highly reactive, toxic oxygens) - pH 5.5 due to H+ intake from cytosol into phagolysosome - these substances, along with 30+ enzymes (lipases, proteases, nucleases) destroy the engulfed microbes - most pathogens die within 30 minutes of phagolysosome formation - virulence factors can hinder phagolysosome efficiency (ex. waxy cell walls of Mycobacterium)

Autoantigens (2)

- AKA "self-antigens" - components of normal body cells derived from normal cellular processes

Asymptomatic (3)

- AKA "subclinical" - infections lack symptoms but may still have signs of infection - signs could be from blood tests of an individual who feels completely healthy

Psychrotolerant (4)

- AKA psychrotrophs - 0-40 C - tolerate but don't grow best in the cold - can infect warm-blooded animals, including humans —> Listeria monocytogenes is a pathogen that can grow in refrigerated food

How to dATP and ATP differ? (2)

- ATP uses ribose sugar & is a ribonucleotide - dATP uses a deoxyribose sugar & is a deoxyribonucleotide

The Viral Envelope - differences in viruses (7)

- Acquired from host cell during viral replication or release --> envelope is a portion of the host's membrane system - Composed of phospholipid bilayer and proteins --> some proteins are virally coded glycoproteins (spikes) - doesn't function like a normal membrane (no endocytosis or active transport) - Envelope proteins/glycoproteins often help w/ Host Recognition - enveloped viruses are more fragile than naked viruses

* Reverse transcriptase inhibitors (3)

- Act against an enzyme HIV uses in its replication cycle to make DNA copies of its RNA genome (reverse transcription) - Do not harm people because humans lack reverse transcriptase - Ex. emtricitabine

* Chloramphenicol and Novobiocin (3)

- Act against prokaryotic DNA gyrase (Enzyme necessary to stabilize DNA while it is being uncoiled by helicase) (Only found in prokaryotes)

T-dependent antibody immunity

- Adaptive immune response resulting in immunoglobulin production that requires the action of a specific helper T cell (Th2) - Most antibody immune responses depend on interaction with helper T cells - act against molecules with multiple repeating epitopes, such as polysaccharides - TH cells secrete IL-4 to activate B cell

Virulence Factors that contribute to virulence

- Adhesion factors - Biofilms - Extracellular enzymes - Toxins - Antiphagocytic factors

Chemical Methods of Microbial Control (from prof notes)

- Affect microbes' cell walls, cytoplasmic membranes, proteins, or DNA - Effect varies with differing environmental conditions - Often more effective against enveloped viruses and vegetative cells of bacteria, fungi, and protozoa

Allergies - Side Effects of Drugs (4)

- Allergic reactions are rare but may be life threatening - Anaphylactic shock (0.1% of Americans) - 300 deaths/year from Penicillin allergy - mild allergies can fade over time (penicillin)

Development of Resistant Microbes (4)

- Americans buy many products that have antiseptics and disinfectants in them - little evidence that these products add to human or animal health - Use of such products promotes development of resistant microbes - ex. M. tuberculosis, P. aeruginosa, E. coli, and S. aureus strains are resistant to common disinfectants and antiseptics

helicase (2)

- An enzyme that "unzips" the double helix of DNA by breaking hydrogen bonds between bases - exposed nucleotide bases in a Replication Fork

Latency of Animal Viruses (5)

- Animal viruses remain dormant in host cells - may go years w/o viral activity - some latent viruses DON'T incorporate into host chromosome - Incorporation of provirus into host DNA is permanent --> induction doesn't occur w/ Provirus

Associations of Microorganisms (4)

- Antagonistic relationships - Commensal relationship - Synergistic relationships - Symbiotic relationships

Antimicrobials - Antimicrobial Chemicals (5)

- Antibiotics, semisynthetic, and synthetic chemicals - act against cell walls/membranes, protein synthesis, DNA replication/transcription - disinfectant; intermediate to low activity - Typically used for treatment of disease - Some used for antimicrobial control outside the body

Classical Pathway of Complement Activation (3)

- Antibodies bind to invading organisms (antigens) - binding begins a series of enzyme activities called a complement cascade - Complement proteins bind to the antigen-antibody complexes (complement fixation)

Neutralization - Antibody Function (2)

- Antibodies can neutralize a toxin by binding to a critical portion of the toxin so that it can no longer harm the body - antibodies can block adhesion molecules on the surface of a bacterium or virus, neutralizing the pathogen's virulence because it cannot adhere to its target cell

Antibody-dependent cell-mediated cytotoxicity (ADCC) - Antibody Function (4)

- Antibodies often coat a target cell by binding to epitopes all over the target's surface - antibodies' stems can then bind to receptors on NK cells (not B or T cells) - similar to opsonization in that antibodies cover the target cell - however, with ADCC the target dies by apoptosis, whereas with opsonization the target is phagocytized

Antigen Processing

- Antigens processed for MHC proteins to display epitopes - Different processes for endogenous and exogenous antigens

Inhibition of Metabolic Pathways - 4/6 Mechanisms of Microbial Drug Action

- Antimetabolic agents can be effective when metabolic processes of pathogen and host differ

Enzymes - Antimicrobial Chemicals (5)

- Antimicrobial enzymes act against microorganisms - high activity against target substrate - Lysozyme (in tears) digests peptidoglycan - Lysozyme reduced bacteria on cheese - Prionzyme removes Prions on medical equipment

Antiviral Agents - Inhibition of Metabolic Pathways (3)

- Antiviral agents can target unique aspects of viral metabolism - ex. Amantadine, rimantadine, and weak organic bases prevent viral uncoating - Protease inhibitors interfere with an enzyme HIV needs in its replication cycle

B Lymphocytes

- Arise and mature in the red bone marrow - Found primarily in the spleen, lymph nodes, and MALT - Small percentage of B cells circulates in the blood - Major function is the secretion of antibodies --> B cells differentiate into plasma cells, and plasma cells secrete antibodies

Heavy Metals - Antimicrobial Chemicals (7)

- Arsenic, zinc, mercury, silver, and copper - denature proteins - low activity bacteriostatic, algicides, and fungistatic (in paint) agents - 1% silver nitrate to prevent blindness caused by N. gonorrhoeae - silver is used in burn creams - Thimerosal used to preserve vaccines (not used much now thanks to single dose vials) - Copper controls algal growth

aflatoxins (6)

- Aspergillus molds growing on grains and nuts produce these nucleotide-altering chemicals - liver catabolizes aflatoxins - by-product converts Guanine to Thymine (GC becomes TA) - results in missense mutations - possibly results in cancer - FDA prohibits excessive # in food

** Various Kinds of Antimetabolic Agents (5)

- Atovaquone, which interferes with electron transport in protozoa and fungi - Heavy metals (such as arsenic, mercury, and antimony), which inactivate enzymes - Agents that disrupt tubulin polymerization and glucose uptake by many protozoa and parasitic worms - Drugs that block the activation of viruses - Metabolic antagonists, such as sulfanilamide, the first commercially available antimicrobial agent

Endocytosis- Entry Method of Animal Viruses (3)

- Attachment of the virus to receptor molecules on the cell's surface stimulates the cell to endocytize the entire virus - ex. Most enveloped viruses; some naked - ex. Adenoviruses (naked) and Herpesviruses (enveloped)

2 Sources of Carbon

- Autotrophs - Heterotrophs

How do Humoral and Cell-Mediated Work Together?

- B cells secrete antibodies to prevent attachment - Tc cells will kill infected cells

Bacterial Endospores - resistance (4)

- Bacillus and Clostridium - survive extreme environments - survive 20+ years in 70% alcohol - viable endospores have been recovered from embalmed Egyptian mummies

2 Main Classes of Mutations

- Base-substitution mutations - Frameshift mutations

Why can the incidence of a disease never exceed the prevalence of that disease?

- Because prevalence includes all cases, both old and new, prevalence must always be larger than incidence. - The estimated number of new cases, the incidence, of HIV/AIDS in adults in the US in 2013 was 47,352. However, the prevalence of HIV/AIDS in the same year was 1,194,039 because more than 1,100,000 patients who got the disease prior to 2013 still survived

3 Main Types of Prokaryotic Reproduction

- Binary Fission - Snapping Division - Budding

Inactivation of Complement (2)

- Body's own cells withstand complement cascade --> Proteins on many cells bind and break down activated complement proteins

One end of a DNA strand is called the 5 ' end. Why?

- because it terminates in a phosphate group attached to a 5 ' carbon

Helper T lymphocyte, TH(CD4 cell) (7)

- CD4 glycoproteins in the cells' cytoplasmic membranes --> CD4 positive (CD4+) cells - help regulate the activity of B cells and cytotoxic T cells during immune responses by providing necessary signals and growth factors - Activate B cells, cytotoxic T cells, macrophages, and dendritic cells - CD4 only binds to MHC II - secrete cytokines - 2 types - distinguished by secretions and cell-surface proteins

What are some end products of fermentation? (4)

- CO2, propionic acid (Swiss cheese) - Lactic acid (cheddar cheese, yogurt, soy sauce) - CO2, ethanol (wine, beer) - Acetone, isopropanol (nail polish remover, rubbing alcohol)

Toxicity - Drug Side Effects (4)

- Cause of many adverse reactions poorly understood - Drugs may be toxic to kidneys, liver, or nerves (polymyxin and aminoglycosides) - Consideration needed when prescribing drugs to pregnant women --> Ex. Tetracyclines, if absorbed by the fetus, will cause malformation of the skull and stained, weakened tooth enamel

Binding of Virus-Infected Cell (picture)

- Cell is virally infected so it will have viral proteins displayed on MHC I - CD8 binds via MHC I

How does innate immunity accomplish recognition of nonself chemicals? (2)

- Certain structures are present on bacteria, fungi, and other microbes that are lacking on human cells. - These structures, called PAMPs, are critical components to the microbes and thus cannot be easily altered by mutation

3 examples of Helminths (from professor notes)

- Cestodes (tapeworms) - Nematodes (roundworms) - Trematodes (flukes)

Drugs (2)

- Chemicals that affect physiology in any manner - ex. alcohol, caffeine, tobacco

Toxins - Virulence Factors

- Chemicals that harm tissues or trigger host immune responses that cause damage - 2 Types (exotoxin and endotoxin)

2 Sources of Energy for Cells

- Chemotrophs - Phototrophs Either require chemicals or light as an energy source for such cellular processes as anabolism, intracellular transport, and motility.

**8 Intermediate Molecules in Kreb's Cycle

- Citric acid - Isocitric acid - α-Ketoglutaric acid - Succinyl-CoA - Succinic acid - Fumaric acid - Malic acid - Oxaloacetic acid

2 Classes of MHC Proteins

- Class I - Class II

Basic shapes of prokaryotic cells (8)

- Coccus (roughly spherical) - Coccobacillus (intermediate between the two; long coccus or short bacillus) - Bacillus (rod-shaped) - Vibrios (curved rods) - Spirilla (STIFF spiral-shaped) - Spirochete (FLEXIBLE, spiral-shaped) - Pleomorphic (variable in shape and size) - Star, triangular, and rectangular

Dermis (4)

- Collagen fibers help skin resist abrasions - NONSPECIFIC - BVs in dermis deliver defensive cells and chemicals - dermal cells secrete antimicrobial peptides

Why can't transient microbiota persist in the body? (3)

- Competition from other microorganisms - Elimination by the body's defense cells - Chemical or physical changes in the body

Complement Cascade (4)

- Complement proteins react with one another in an amplifying sequence of chemical reactions in which the product of each reaction becomes an enzyme that catalyzes the next reaction many times over - Complement enzymes cleave other, inactive complement proteins, producing fragments that are active and are designated with lowercase letters. For example, inactive complement protein 3 (C3) is cleaved into active fragments C3a and C3b - Most fragments have specific and important roles in achieving the functions of the complement system. Some combine to form new enzymes; some act to increase vascular permeability, which increases diapedesis; others enhance inflammation; some act as opsonins; and still others are involved as positive chemotactic factors, attracting phagocytes - MAC

Lymphatic System

- Composed of lymphatic vessels and lymphatic cells, tissues, and organs - Screen the tissues of the body for foreign antigens by providing a surveillance point - B and T cells are typically found in the lymphatic system

Aldehydes - Antimicrobial Chemicals

- Compounds containing terminal (-CHO) groups - Cross-link functional groups to denature proteins and inactivate nucleic acids - disinfectant/embalming fluid; high activity - Glutaraldehyde disinfects (10 min) and sterilizes (10 hrs) - Formalin

Culturing Viruses in Cell Culture (3)

- Consists of cells isolated from an organism and grown on a medium or in a broth - can be less expensive than even eggs - 2 types (diploid and continuous)

Microbial Antagonism (professor notes; shorter version) (4)

- Consume nutrients - Create an environment unfavorable to other microorganisms - Help stimulate the body's second line of defense - Promote overall health by providing vitamins to host

Granulocytes (4)

- Contain large granules that stain different colors - Basophils stain blue with the basic dye methylene blue - Eosinophils stain red to orange with the acidic dye eosin - Neutrophils also known as polymorphonuclear leukocytes (PMNs), stain lilac with a mixture of acidic and basic dyes

2 Major Phyla of Archaea

- Crenarchaeota - Euryarchaeota (there are 3 minor phyla that only contain a few species)

How does using mutagens in Salmonella help the FDA? (3)

- DNA in cells is very similar - the ability of a chemical to cause mutations in Salmonella indicates that it is likely to cause mutations in humans as well - if a chemical is mutagenic in Salmonella, it can be tested to see if it is carcinogenic too!

Transduction - Types of Horizontal Gene Transfer

- DNA is transferred from one cell to another via a replicating virus - Generalized & Specialized

6 Types of General Culture Media

- Defined (synthetic) media; (exact chemical composition is known and controlled to facilitate the growth of specific microbes) - Complex media - Selective media - Differential media - Anaerobic media - Transport media

Virulence

- Degree of pathogenicity; relative ability of a pathogen to infect a host and cause disease - Virulence factors contribute to virulence (new card)

Acquisition of Normal Microbiota (3)

- Development in the womb free of microorganisms (axenic environment) - Microbiome begin to develop during birthing process - Much of one's resident microbiota established during first months of life

Acute Inflammation (7)

- Develops quickly and is short lived - Typically beneficial - results in the resolution of whatever condition precipitated it - Important in the second line of defense --> Dilation and increased permeability of the blood vessels --> Migration of phagocytes --> Tissue repair

How to measure microbial reproduction

- Direct methods not requiring incubation - Direct methods requiring incubation - Indirect Methods - Genetic Methods

Prion PrP

- Disease-causing form with β-pleated sheets - Prion PrP changes shape of cellular PrPso it becomes prion PrP, prion PrP being to clump together. As clumps of prion PrP propagate throughout the brain, neurons stop functioning properly and die due to loss of membrane functions, leaving holes.

Reportable Diseases (picture) (3)

- Diseases for which hospitals, physicians, and other health care workers are required to report cases to state health departments and then forward the data to the CDC - Some diseases must be reported to the state health department if confirmed or suspected. - Ex. Anthrax, botulism, measles, hepatitis A, influenza, Ebola, cholera, rabies, tuberculosis, pertussis, and Creutzfeldt-Jakob disease.

Zoonoses (4)

- Diseases that spread naturally from animal hosts to humans - over 200 identified - The more similar an animal's physiology is to human physiology, the more likely its pathogens can affect human health - difficult to eradicate

Public Health Education (2)

- Diseases transmitted sexually and through the air are difficult to control - Public health agencies campaign to educate the public on healthful choices to limit disease

Helminths (6)

- Domain Eukarya, Kingdom Animalia - parasitic worms - multicellular - not a true microbe because the adults aren't microscopic (tape worms can be 33+ ft) - considered part of microbiology because most identification and diagnosis is via microscope — diseases can be idtentified by the presence of eggs in samples

Fungi (6)

- Domain Eukarya, Kingdom Fungi - cell walls made of Chitin - nonmotile - reproduce sexually and asexually - not photosynthetic - include molds/yeasts

Protozoa (10)

- Domain Eukarya, multiple Kingdoms - "Animal-like" protist - single-celled eukaryotes - NO cell wall - similar to animals in their nutritional needs & cellular structure - most are capable of locomotion (pseudopodia, cilia, flagella) - some are nonmotile in their mature forms - many live free in water; some in animals, causing disease - most produce asexually, though some are sexual

Algae (6)

- Domain Eukarya, multiple Kingdoms - unicellular OR multicellular "photosynthetic" protist —make their own food from CO2 and H2O using energy from sunlight - aquatic and marine habitats - plant-like BUT NOT - categorized by pigmentation, storage products, and composition of cell wall

Specificity of the B cell receptor (BCR)

- Each B lymphocyte has multiple copies of the B cell receptor on the cell membrane - Each B cell generates a single BCR - Two variable regions of the BCR form the antigen-binding sites - Each BCR recognizes only one epitope - The entire repertoire of an individual's BCRs is capable of recognizing millions of different epitopes

Ionizing Radiation (3)

- Ejects electrons from atoms to create ions (wavelength smaller than 1 nm) - disrupt H bonds; denature molecules (DNA); cause fatal mutations and cell death - ex. Electron beams, gamma rays, some X-rays

enrichment culture (2)

- Encourages the growth of a desired microbe by increasing very small numbers of a desired organism to detectable levels - uses selective media

Why is catabolism necessary? (3)

- Energy in nutrients is too far spread through chem. bonds to use for anabolism - Catabolism releases energy from nutrients to be concentrated and stored in high-energy phosphate bonds of ATP - This process is Phosphorylation

Outcomes of Fever (4)

- Enhances effects of interferons - Inhibits growth of some microbes - Sequestration of iron - May enhance the activities of phagocytes, cells of specific immunity, and the process of tissue repair

Neutrophil Chemicals (2)

- Enzymes in a neutrophil's cytoplasmic membrane add electrons to oxygen, creating highly reactive superoxide radical O−2O2− and hydrogen peroxide (H2O2).(H2O2). Another enzyme converts these into hypochlorite, the active antimicrobial ingredient in household bleach. These chemicals can kill nearby invaders. - Yet another enzyme in the neutrophil's membrane makes nitric oxide, which is a powerful inducer of inflammation.

** Transcriptional Differences Between Eukaryotes and Prokaryotes (6)

- Euk. cell transcribes RNA in the nucleolus of nucleus (Prok. in cytosol) - Euk. cell transcribes RNA inside any mitochondria and chloroplasts - Euk. cells have 3 types of nuclear RNA polymerase (listed on another card) - Euk. cells use several protein transcription factors (instead of bacteria's single sigma factor) - Euk. RNA polymerases shed transcription factors and recruit elongation factor polypeptides - Euk. cells must process mRNA before beginning polypeptide translation (listed on another card)

Eukaryotic vs. Prokaryotic mRNA (4)

- Euk. cells extensively process pre-mRNA to make mRNA - a processed Euk. mRNA contains instructions for only one polypeptide - Prok. mRNA often contains instructions for more than one polypeptide - Euk. mRNA isn't tranlsated until it's fully transcribed, processed, and has left the nucleus

** Eukaryotic Translation vs. Prokaryotic Translation (3)

- Euk. translation initiation occurs when the small ribo. subunit binds to the 5 ' Guanine cap (instead of a specific nucleotide sequence) - Euk.'s first AA is Methionine (instead of f-mylmehionine) - RER ribosomes can synthesis polypeptides into the cavity of the RER

5 Classes of Antibodies (picture)

- IgM: first antibody produced - IgG: most common and longest-lasting antibody - IgA: associated with body secretions (mammary glands, lacrimal glands, mucous membranes) - IgE: involved in response to parasitic infections and allergies in developed countries - IgD: exact function unknown

Differences between Prokaryotic and Eukaryotic DNA Replication (4)

- Eukaryotes use different DNA polymerases (4 types) - Greek letters for Euk. DNA polymerases: (α, δ, ε, γ) - Large eukaryotic chromosomes requires thousands of origins per molecule, each with 2 replication forks - Eukaryotic Okazaki fragments are shorter than those of bacteria; 100-400 bp long (instead of 1-2k bp) - Plant and animal cells methylate Cytosine bases ONLY

Eukaryotic Nuclear Chromosomes (6)

- Eukaryotic cells have more than one nuclear chromosome in their genomes - some euk. cells (such as mammalian RBCs) lose their chromosomes as they mature - all euk. nuclear chromosomes are linear and within a nucleus - euk. cells are often Diploid (they have 2 copies of their genome) - complex - have histones (like arachael chromosomes)

Eukaryotic Nuclear Chromosomes vs. Prokaryotic Chromosomes (6)

- Eukaryotic chromosomes are all linear - Prokaryotic chromosomes are often all circular - Eukaryotes are often diploid (2 copies of each chromosome) - Prokaryotes are haploid (1 copy of each chromosome) - Eukaryotes have a nucleus and nuclear envelope; Prokaryotes don't - Eukaryotes have much more DNA than Prokaryotes therefore their chromosomes are much more elaborate/complex

Factors Influencing Healthcare- Associated Infections

- Exposure to numerous pathogens present in the health care setting, including many that are resistant to antimicrobial agents - The weakened immune systems of patients who are ill, making them more susceptible to opportunistic pathogens - Transmission of pathogens among patients and health care workers—from staff and visitors, to patients, and even from one patient to another via activities of staff members (including invasive procedures and other iatrogenic factors)

Viroids (9)

- Extremely small, circular pieces of ssRNA that are infectious and pathogenic in plants - Similar to RNA viruses, but lack capsid - May appear linear due to H bonding - Viroid RNA does not code for proteins - Viroid RNA adheres to complementary plant RNA --> Plant enzyme degrades the dsRNA --> results in a disease state ex. Potato spindle tuber viroid (PSTV) --> Causes stunted growth in potatoes

Antiphagocytic factors - Virulence Factors (7)

- Factors prevent phagocytosis by the host's phagocytic cells - Allow pathogens to remain in a host for longer time --> Bacterial capsule ----> Composed of chemicals not recognized as foreign ----> Slippery and difficult for phagocytes to engulf --> Antiphagocytic chemicals ----> Prevent fusion of lysosome and phagocytic vesicles

Prion Diseases (7)

- Fatal neurological degeneration, fibril deposits in brain, and loss of brain matter - Spongiform encephalopathies --> Large vacuoles form in brain that have characteristic spongy appearance --> Bovine spongiform encephalopathy (mad cow disease) - Scrapie in sheep - Chronic wasting disease of deer and elk - Creutzfeldt-Jakob disease in humans

4 Types of Plasmids (AKA Factors)

- Fertility (F) plasmids - Resistance (R) plasmids - Bacteriocin plasmids - Virulence plasmids

4 Categories of Carrier Molecules for Electron Transport

- Flavoproteins - Ubiquinones - Metal-containing proteins - Cytochromes

Attachment Proteins - Adhesion in Infection (6)

- Found on viruses (attachment proteins) and many bacteria (adhesions) - Viral or bacterial ligands bind host cell receptors (glycoproteins) --> Interaction can determine host cell specificity - Changing/blocking a ligand or its receptor can prevent infection - Inability to make attachment proteins or adhesins renders microorganisms avirulent - Some bacterial pathogens attach to each other to form a biofilm

How do viruses differ? (6)

- Genetic Material - Hosts (cells they attack) - Size - Capsid Morphology - Viral Shapes - Viral Envelope

Spirochetes (3)

- Gram-negative, spiral shaped bacteria - have endoflagella that form an Axial Filament (wraps around cell between outer membrane and cytoplasmic membrane) - rotation of the endoflagella and axial filament allow the spirochete to corkscrew and bury itself in tissue

DNA nucleotides differ from one another only in the kind of base present. (4)

- Guanosine triphosphate deoxyribonucleotide (dGTP) (guanine base) - Cytidine triphosphate deoxyribonucleotide (dCTP) (cytosine base) - Thymidine triphosphate deoxyribonucleotide (dTTP) (thymine base) - Adenosine triphosphate deoxyribonucleotide (dATP) (adenine base)

Peroxide Anion (3)

- H2O2 (hydrogen peroxide) formed by superoxide dismutase or other reactions, contains peroxide anion - Aerobes contain catalase or peroxidase that detoxify this anion - catalase converts (H2O2) into (H2O) and (O2)

Hospital Epidemiology (8)

- Healthcare-associated (Nosocomial) Infections - A hospital or healthcare facility-acquired infection - exogenous and endogenous - Control of healthcare-associated infections - Requires aggressive control measures --> Disinfection, medical asepsis, good housekeeping, bathing, and proper hygiene - Hand washing is the most effective way to reduce HAIs --> Studies have shown that the single most effective way to reduce nosocomial infections is effective handwashing

How do heavy metals function?

- Heavy-metal ions are antimicrobial because they combine with sulfur atoms in molecules of cysteine, an amino acid. Such bonding denatures proteins, inhibiting or eliminating their function.

Osmotic Pressure - Physical Methods of Microbial Control (3)

- High concentrations of salt or sugar in foods to inhibit growth - Cells in hypertonic solution of salt or sugar lose water - Fungi have greater ability than bacteria to survive hypertonic environments

* What must be considered for the synthesis and assembly of animal viruses?

- How is the mRNA synthesized? - What molecule serves as a template for nucleic acid replication?

2 Types of Adaptive Immune Responses

- Humoral/Antibody - Cell-mediated - both paths stimulate and regulate innate immunity - both act directly against the specific pathogen that initiated the adaptive response

6 Enzyme Categories Based on Mode of Actions

- Hydrolases (add water) - Isomerases (rearranges a molecule) - Ligases or polymerases (join two molecules) - Lyases (split large molecules) - Oxidoreductases (remove or add electrons) - Transferases (transfer functional groups)

Contagious Disease (2)

- If a communicable disease is easily transmitted between hosts - Ex. chicken pox or measles

The thin epithelium of a mucous membrane provides a less efficient barrier than the multiple layers of dead cells found at the skin's surface. How does it keep microbes from invading?(3)

- In some cases, it doesn't keep all pathogens out! --> respiratory and reproduction systems are common portals of entry - still, tight cell packing and continual shedding prevents the entry of many pathogens

Nonliving Reservoirs (Fomites) - Reservoirs of Infectious Diseases (2)

- Inanimate things such as soil, water, and food - Presence of microorganisms often due to contamination by feces or urine

Exogenous Antigens (2)

- Include toxins and other components of microbial cell walls, membranes, flagella, and pili - originate from microbes located outside the body's cells

Examples of Antigens (5)

- Include various bacterial components (cell walls, capsules, pili, flagella) - as well as proteins of viruses, fungi, and protozoa - Many toxins and some nucleic acid molecules - Food allergens - dust contains mite feces, pollen grains, dander (flakes of skin), and more antigenic and allergenic particles

What is the purpose of vasodilation in inflammation? (3)

- Increased blood flow due to vasodilation delivers more neutrophils and monocytes to the site of infection - leukocytes then adhere to receptors lining the vessels (margination) - diapedesis occurs within an hour of infection

Tetherin (not in book; professor notes) (picture)

- Induced by IFN α and β; part of antiviral response in neighboring cells - Impairs release of many enveloped viruses

Human Carriers - Reservoirs of Infectious Diseases (5)

- Infected individuals who are asymptomatic can be infectious to others - Some individuals eventually develop illness, while others never get sick - If you are infected, it does not mean you develop illness --> Ex. vaccines prevent illness, not infection - Healthy carriers may have defensive systems that protect them

Transmission of Prions

- Ingestion of infected tissue - transplant of infected tissue - contact between infected tissue with mucous membrane or skin abrasions

Nucleotide/Nucleoside Analogs (5)

- Interfere with function of nucleic acids - Distort shapes of nucleic acid molecules and prevent further replication, transcription, or translation - Most often used against viruses due to viral inability to correct mistakes during genome replication - ex. HIV treatment - Effective against rapidly dividing cancer cells (complete viral nucleic acid synthesis is more rapid than cellular nucleic acid synthesis)

Conditions that provide opportunities for pathogens (4)

- Introduction of normal microbiota into unusual site in body (E. Coli in urethra) - Immune suppression (HIV patients) - Changes in the normal microbiota (LACK of microbial antagonism/competition) - Stressful conditions

Halogens - Antimicrobial Chemicals (5)

- Iodine, chlorine, bromine, and fluorine - denatures proteins/enzymes - Kills vegetative bacteria, fungi, fungal spores, and some endospores, cysts, and viruses - antiseptic/disinfectant/water purification; intermediate activity - ex. Betadine (iodophore), chlorine bleach

Circumstances Making Satisfying Koch's Postulates Difficult (2)

- It is not possible to establish a single cause for such infectious diseases as pneumonia, meningitis, and hepatitis because the names of these diseases refer to conditions that can be caused by more than one pathogen. For these diseases, laboratory technicians must identify the etiologic agent involved in any given case. - Some pathogens may have been ignored. For example, gastric ulcers were long thought to be caused by excessive production of stomach acid in response to stress, but the majority of such ulcers are now known to be caused by a long-overlooked bacterium, Helicobacter pylori

Alcohols - Antimicrobial Chemicals (6)

- Kill fungi, protozoan cysts, enveloped viruses, pathogenic bacteria - denature proteins / disrupt cell membrane - antiseptic/disinfectant/solvent in tinctures; intermediate to low activity - Pure alcohol is not effective; typically 70-90% solutions - Evaporates quickly, so may not contact all microbes long enough to be effective - More effective than soap in removing bacteria from skin, but not effective against many viruses (never substitute for hand-washing)

Boiling - Moist Heat Methods (2)

- Kills vegetative cells of bacteria and fungi, protozoan trophozoites, most viruses within 10 minutes at sea level - boiling TIME is the critical factor

Why was microbiology slow to develop? (2)

- Leeuwenhoek was very secretive; it took nearly 100 yrs for scientists to create microscopes of equivalent quality - in the 1700s, microbes were thought to be insignificant to human affairs

Mucous Membrane - Portals of Entry (6)

- Line the body cavities that are open to the environment - Provide a moist, warm environment hospitable to pathogens - Respiratory tract is the most common site of entry --> Entry is through the nose, mouth, or eyes - Gastrointestinal tract may be route of entry --> Must survive the acidic pH of the stomach

Endotoxin (3)

- Lipid A! - released from phagocytized/dead Gram-negative bacteria - triggers fever, blood clotting, inflammation, shock, death

2 other catabolic pathways (5)

- Lipids & proteins contain energy in their chemical bonds - can be converted into precursor metabolites - serve as substrates in glycolysis and the Kreb's cycle Lipid Catabolism Protein Catabolism

What are some notable bacteria that can survive refrigeration? (2)

- Listeria monocytogenes (can multiply in refr. food) - Yersinia (can multiply in refr. food and be passed on to blood recipients)

Epidemiology and Public Health (5)

- Local, state, national, and global agencies share information concerning disease - The United States Public Health Service --> Branches include: CDC, NIH, FDA - World Health Organization (WHO) --> Coordinates public health efforts worldwide

How can a virus enter a thick cell wall? (4)

- Lysozyme, a protein enzyme, is carried within the viral capsid and can weaken the peptidoglycan of the cell wall - the phage's tail can force a hollow tube through the cell wall and membrane - genome is injected through tube - empty capsid is left outside

Retarding Resistance

- Maintain high concentration of drug in patient for sufficient time --> Kills all sensitive cells and inhibits others so immune system can destroy --> Discontinuing too early promotes resistance - Use antimicrobial agents in combination --> Synergism vs. antagonism --> Synergism: one drug enhances the effect of a second drug - Ex: clavulanic acid enhances the effect of penicillin by deactivating beta-lactamase - Use antimicrobials only when necessary - Develop new variations of existing drugs --> second- and third-generation drugs - Search for new antibiotics, semisynthetics, and synthetics --> Bacteriocins: antibacterial proteins in bacterial plasmids --> Design drugs complementary to the shape of microbial proteins to inhibit them

Plasma Cells (8)

- Majority of cells produced during B cell proliferation - Only secrete antibody molecules complementary to the specific antigen - Short-lived cells that die within a few days of activation - Their antibodies (for weeks) and progeny (for years) can persist - as the plasma cell clones replicate, each one slightly modifies its antigen-binding-site genes such that each descendant secretes antibodies with slightly different variable regions - Each plasma cell produces different classes of antibodies - They begin by secreting IgM and then, through class switching, secrete IgG or IgA or IgE - Class switching is primarily controlled by Th cells and is irreversible

Portals of Exit (7)

- Many portals of exit are the same as portals of entry - Pathogens often leave hosts in materials the body secretes or excretes --> Secretions (earwax, tears, nasal secretions, saliva, sputum, and respiratory droplets) --> Blood (via arthropod bites, hypodermic needles, or wounds) --> Vaginal secretions or semen --> Milk from mammary glands --> Excreted Bodily Wastes

Indirect Methods for Measuring Microbial Growth

- Metabolic Activity - Dry Weight - Turbidity

the use-dilution test (4) - Methods to Measure Efficiency of Antimicrobial Agents

- Metal cylinders dipped into broth cultures of bacteria - Contaminated cylinder immersed into dilution of disinfectant - Cylinders removed, washed, and placed into tube of medium - Most effective agents entirely prevent growth at highest dilution - Current standard test in the U.S.

Aerotolerant anaerobes (4)

- Microorganism that prefers anaerobic conditions but can tolerate exposure to low levels of oxygen - don't use aerobic metabolism - they have some enzymes that detoxify oxygen's poisonous forms - many prokaryotes and few protozoa ex. lactobilli that turn cucumbers into pickles or milk into cheese

Photoautotrophs (3)

- Microorganism that requires light energy and uses carbon dioxide as a carbon source. - Plants, algae, cyanobacteria (use H2O as electron source to reduce CO2, producing O2 as a by-product) - Green sulfur bacteria and purple sulfur bacteria (use H2S a electron source; don't produce O2)

Microaerophiles (4)

- Microorganism that requires low levels of oxygen - require oxygen levels of 2-10% (this concentration is found in the stomach) - our atmosphere damages them presumably from their limited ability to detoxify H2O2 and superoxide radicals - many prokaryotes and a few protozoa

Chemoautotroph (2)

- Microorganism that uses carbon dioxide as a carbon source and catabolizes organic molecules through redox reactions for energy - Hydrogen, sulfur, and nitrifying bacteria, some archaea

Chemoheterotrophs (4)

- Microorganism that uses organic compounds for both energy and carbon - Aerobic respiration : most animals, fungi, protozoa and many bacteria - Anaerobic Respiration: some animals, protozoa, bacteria, and archaea - Fermentation: some bacteria, yeasts, and archaea

Barophiles (4)

- Microorganisms requiring the extreme hydrostatic pressure found at great depth below the surface of the water - their membranes and enzymes depend on pressure to maintain their 3D shapes - die when brought to the surface quickly (proteins denature) - can't cause disease in organisms that don't live at the same extreme depth

Faculative Anaerobes (4)

- Microorganisms that can live with/without oxygen. - some aerobic organisms can maintain life via fermentation or anaerobic respiration - metabolic efficiency is often reduced in absence of oxygen - a few yeasts and numerous prokaryotes ((faculative aerobe can mea the same thing but the term is rarely used))

Photoheterotrophs (3)

- Miroorganism that requires light and gains carbon from the catabolism of organic compounds - Green and purple non-sulfur bacteria - some archaea

Eukaryotic Extranuclear Chromosomes (6)

- Mitochondria chromosomes are circular - Chloroplast chromosomes are linear - both resemble prokaryotic chromosomes - code about 5% of RNA & polypeptides for replication/function (nuclear chromo. code for the rest) - mitochondria-coded and chloroplast-coded polypeptides becomes functional ONLY when associated w/ polypeptides coded by nuclear chromosomes - don't alone code for functional proteins

Assembly and release of animal viruses (6)

- Most DNA viruses assemble in nucleus - Most RNA viruses develop solely in cytoplasm - Number of viruses produced depends on type of virus and size and initial health of host cell - Naked (nonenveloped) viruses are released by exocytosis or lysis - Enveloped viruses cause "persistent infections" --> Host cells shed viruses slowly and steadily

Inhibition of Synthesis of Bacterial Walls (6)

- Most common agents prevent cross-linkage of NAM subunits - Beta-lactams are the most common drugs - functional proteins are beta-lactam rings - Beta-lactams irreversibly bind to PBP - ex. penicillin, cephalosporins, carbapenems - prompts cell lysis

Host of Viruses - differences in viruses (4)

- Most viruses infect only particular host's cells --> due to affinity between Viral surface proteins and their complementary Cell surface proteins - May be so specific they infect only particular kind of cell in a particular host --> HIV infects Helper T lymphocytes in humans

Antimicrobial agents effective against Mycobacteria must be administered over months/years. Why?

- Mycobacteria typically reproduce only every 12 to 24 hours - agents must be administered over long periods of time to be effective

Animal and cell culture - 2 special culture techniques (2)

- Mycobacterium leprae, the causative agent of leprosy, is cultured in armadillos - Treponema pallidum, the causative agent of syphilis, is cultured in rabbits

**Electron Transport steps

- NADH delivers the H and therefore the electron H is carrying to complex I - FADH2 delivers to complex II - Each NADH-carried electron can generate 3 ATP - Each FADH2-carried electron can generate 2 ATP

lipoglycopeptides (5)

- NON beta-lactams - directly interrupt alanine-alanine bridges between NAM subunits in many Gram-positive bacteria - ex. vancomycin, cycloserine, oritavancin - bacteria lacking alanine-alanine bridges are naturally resistant - prompts cell lysis

Isoniazid and Ethambutol (3)

- NON beta-lactams - disrupt mycolic acid formation in mycobacterial species - must be administered for months or even years

ph - physical req. for microbial growth

- Neutrophiles - Acidophiles - Alkalinophiles

nonprofessional antigen-presenting cells (4)

- Non-professional APCs do not typically express MHC class II molecules - may present antigens under certain conditions - Ex. microglia in the brain - Ex. stellate macrophages (Kupffer cells) in the liver

Destruction of Prions

- Normal sterilization procedures do not deactivate prions - Prions destroyed by incineration or autoclaving in concentrated sodium hydroxide

PrP (4)

- Normally, nearby proteins and polysaccharides force PrPinto cellular shape - Mutations in PrP gene can result in formation of prion PrP - Human cellular PrPonly misfolds if it contains methionine as the 129th amino acid. - About 40% of humans have this type of PrPand are thus susceptible to prion disease

Parenteral Route - Portals of Entry (4)

- Not a true portal of entry - Means by which portals of entry can be circumvented - Pathogens deposited directly into tissues beneath the skin or mucous membranes --> Ex: nail, thorn, hypodermic needle, bites, stab wound, surgery

Chemical Mutagens (3)

- Nucleoside Analogs - Nucleotide Analogs - Frameshift Mutagens

Clonal Deletion (4)

- Occurs when lymphocytes mature - Vital that immune responses not be directed against autoantigens - Body eliminates self-reactive lymphocytes - Lymphocytes that react to autoantigens undergo apoptosis

Microbiome (4)

- Organisms that colonize the body's surfaces without normally causing disease - AKA normal microbiota - AKA normal flora - AKA indigenous microbiota

Electron/Hydrogen Sources for Cells

- Organotrophs - Lithotrophs

Skin - Portals of Entry (4)

- Outer layer of dead skin cells acts as a barrier to pathogens - Some pathogens can enter through openings or cuts - Others burrow into or digest outer layers of skin - Bacteria cannot enter though intact, healthy skin

Dendritic Cells (4)

- PRIMARY APC - have many long, thin cytoplasmic processes called dendrites - Phagocytic dendritic cells are found under the surface of the skin and mucous membranes - After acquiring antigens, dendritic cells migrate to lymph nodes to interact with cells of adaptive immunity

Multiple Resistance and Cross Resistance (5)

- Pathogen can acquire resistance to more than one drug - Common when R-plasmids exchanged - Develop in hospitals and nursing homes --> Constant use of drugs eliminates sensitive cells - Superbugs

Oxidizing Agents - Antimicrobial Chemicals (8)

- Peroxides, ozone, and peracetic acid - Oxidize microbial enzymes - VERY effective against Anaerobes - H2O2 can disinfect/sterilize BUT it's not good for open wounds as catalase neutralizes it - antiseptic (deep wounds)/disinfectant/water purification/sterilizes food processing and medical equipm. - high activity - ex. Ozone treatment of drinking water - ex. Peracetic acid is a sporicide to sterilize equipment

4 Basic Groups Categorized by Carbon and Energy Sources

- Photoautotrophs - Chemoautotrophs - Photoheterotrophs - Chemoheterotrophs

Artificially Acquired Active Immunity (3)

- Physicians induce immunity in their patients by introducing antigens in the form of vaccines - patients' own immune systems then mount active responses against the foreign antigens - "injection of immune serum (gamma globulin)"

Synthesis of RNA viruses differs from DNA virus replication (2)

- Positive-sense (+) viral RNA can act as mRNA - Negative-sense (-) viral RNA cannot be directly translated

* Differences between bacterial and animal virus replication results from: (3)

- Presence of envelope around some viruses - Eukaryotic nature of animal cells - Lack of cell wall in animal cells

Adhesion in Infection (6)

- Process by which microorganisms attach themselves to cells - Required to successfully establish colonies within the host - Adhesion Factors (new card) - Attachment proteins (new card)

7 Mechanisms of Microbial Resistance

- Produce enzyme that destroys or deactivates drug - Slow or prevent entry of drug into the cell - Alter target of drug so it binds less effectively - Alter their own metabolic chemistry - Pump antimicrobial drug out of the cell before it can act - Bacteria in biofilms slow drug diffusion - Mycobacterium tuberculosis produces MfpA protein, binds and protects DNA gyrase. First known method that uses a protein to act as a decoy

Memory B Cells (4)

- Produced by B cell proliferation but do not secrete antibodies - Have BCRs complementary to the epitope that triggered their production - Long-lived cells that persist in the lymphoid tissue (20+ yrs) - Initiate antibody production if antigen is encountered again

Interference w/ Prokaryotic Ribosomes

- Prok. ribosomes are 70S (30S and 50S subunits) - Euk. ribosomes are 80S (40S and 60S subunits) - drugs can selectively target translation - these can still harm eukaryotic organisms

Prions (5)

- Proteinaceousinfectious agents that lack nucleic acid - Cytoplasmic membrane protein called PrP --> Made by all mammals, plays a role in the normal activity of the brain but exact function unknown --> Normal structure with α-helices called cellular PrP --> Prion Prp is the bad, infectious version

Neoplasia (2)

- Uncontrolled cell division in multicellular animal - Mass of neoplastic cells is a "Tumor"

Interferons (5) (picture)

- Proteins released by host cells to nonspecifically inhibit the spread of viral infections --> lack of specificity means that interferons produced against one viral invader protect somewhat against infection by other types of viruses as well - Signals chemotaxis of most immune cells (macrophages, NK cells etc.) - Cause many symptoms associated with viral infections (muscle aches, chills, fever etc.) - Two types: --> Type I (α and β) --> Type II (γ)

5 overlapping groups of microbes based on preferred temperature ranges

- Psychrophiles (req. below 20 C) - Psychrotolerants - Mesophiles - Thermophiles - Hyperthermophiles

** How does RNA Polymerase differ from DNA Polymerase? (7)

- RNA polymerase unwinds DNA by itself; no helicase needed - RNA polymerase doesn't need a primer - RNA polymerase copies only one DNA strand - RNA polymerase is slower than DNA polymerase III (only about 50 nucleotides per second) - RNA polymerase incorporates ribonucleotides instead of deoxyribonucleotides - Uracil replaces Thymine - RNA polymerase proofreading is less efficient; leaves a base-pair error every 10,000 nucleotides

Elongation of RNA Transcript - second step of bacterial transcription (7)

- RNA transcription doesn't actually begin in the promoter region but at a spot 10 nucleotides away!!! - triphosphate ribonucleotides align their complements in the open DNA "bubble" 1. RNA polymerase links together 2 adjacent ribonucleotides using the energy from the phosphate bonds of the 1st ribonucleotide - enzyme moves down the strand, elongating the RNA by repeating the process - only ONE of the separated DNA strands is transcribed! - In prokaryotes, many RNA polymerase may concurrently transcribe the same gene - this way, a cell simultaneously produces numerous identical copies of RNA from a single gene

Ideal Antimicrobial Agents Are: (6)

- Readily available - Inexpensive - Chemically stable (so that it can be transported easily and stored for long periods of time) - Easily administered - Nontoxic and nonallergenic - Selectively toxic against a wide range of pathogens

Shape of Antigens

- Recognized by three-dimensional regions called epitopes (antigenic determinants) --> the actual part of an antigen that determines an immune response

T Cell Regulation (6)

- Regulation needed to prevent T cell response to autoantigens - TH cells require additional signals from an antigen-presenting cell --> Interaction of the TH cell and antigen-presenting cell stimulates the TH cell to respond to the antigen --> APC will secrete IL-12 to fully activate TH cell - TC cells require IL-2 from TH cell to fully activate - Regulatory T cells also moderate cytotoxic T cell activity

Transient Microbiota (3)

- Remain in the body for short period - Found in the same regions as resident microbiota - can't persist in the body

Regulatory T lymphocyte, TReg

- Represses adaptive immune responses (hopefully after successfully eliminating threat) - AKA "suppressor T cells" - activated by contact with other immune cells - secrete different cytokines than Helper T cells - suppress immune responses and promote tolerance of certain antigens

Cross Resistance (3)

- Resistance to one drug may confer resistance to similar drugs - Occurs when drugs are similar in structure - Ex. Resistance to one aminoglycoside drug, such as streptomycin, may confer resistance to similar aminoglycoside drugs

Rho-Dependent Termination of Transcription - 2/2 types of termination of bacterial transcription (4)

- Rho is a termination protein - Rho bnds to a specific RNA sequence near the end of the RNA transcript - Rho moves toward RNA polymerase at the end of the 3 ' end of the growing RNA molecule, pushing between RNA polymerase and the DNA strand, forcing them apart - this releases RNA polymerase, the RNA transcript, and Rho

Extracellular Enzymes - Virulence Factors (7)

- Secreted by the pathogen - Dissolve structural chemicals in the body - Help pathogen maintain infection, invade, and avoid body defenses - Important to virulence of the pathogen --> Mutant species that do not secrete the enzymes are often avirulent - Ex. Hyaluronidase and collagenase - Ex. Coagulase and kinase

Antibiotic (2)

- Selman Waksman: "antimicrobial agents that are produced naturally by an organism" - TODAY: antibacterial agent, including synthetic compounds and excluding agents with antiviral and antifungal activity

3 Direct Methods Requiring Incubation - how to measure microbial reproduction

- Serial dilution and viable plate counts - Membrane filtration - "Most Probable Number Method"

Inhibition of Nucleic Acid Synthesis - 5/6 Mechanisms of Microbial Drug Action (4)

- Several drugs block DNA replication or mRNA transcription - Drugs often affect both eukaryotic and prokaryotic cells (because DNA only slightly differs) - Not normally used to treat infections but are used for certain viral infections - Primarily used in research and perhaps to slow cancer cell replication

dsDNA viruses of animals (3)

- Similar to replication of cellular DNA --> Viral genome replicated in the nucleus --> Viral proteins made in the cytoplasm

Portals of Entry (3)

- Sites through which pathogens enter the body - 3 major pathways (skin, mucous membrane, placenta) - Entry via the parenteral route circumvents the usual portals (4th entry point)

Reservoirs of Infection

- Sites where pathogens are maintained as a source of infection - 3 types (animal reservoirs, human carriers, nonliving reservoirs)

Immune Response Cytokines (4)

- Soluble regulatory proteins that act as intercellular signals - Cytokines secreted by various leukocytes - Cytokine network --> The complex web of signals among all the cells of the immune system

* Are viruses alive?

- Some consider viruses as complex pathogenic chemicals - Others consider viruses the least complex living entities and perfect parasites --> Use sophisticated methods to invade cells --> Have the ability to take control of their host cell --> Are able to replicate themselves --> Evolve over time

Activators - enzyme reaction rate factors (2)

- Some enzymes are activated when a cofactor binds to an allosteric site (site other than the active site) - in allosteric activation, the binding of an activator to an allosteric site cause's the enzyme's active site to change shape, activating the enzyme

Exceptions to Koch's Postulates (3)

- Some pathogens have not been cultured in the laboratory - Some diseases are caused by a combination of pathogens or by a combination of a pathogen and physical, environmental, or genetic cofactors - Ethical considerations prevent applying Koch's postulates to diseases and pathogens that occur in humans only (proving HIV causes AIDS)

How do cancer-causing viruses work? (3)

- Some viruses carry copies of oncogenes as part of their genomes - Some viruses promote oncogenes already present in host - Some viruses interfere w/ tumor repression

Acquired Immunity

- Specific immunity acquired during an individual's life - distinguished as either Active or Passive Naturally Acquired - Response against antigens encountered in daily life Artificially Acquired - Response to antigens introduced via a vaccine

Most Probable Number Method - direct method requiring incubation (5)

- Statistical estimation of the zie of a microbe pop. based upon the dilution of a sample required to eliminate microbial growth. - useful for counting microbes that don't grow on solid media - useful for when bacterial counts are required routinely - useful when samples of wastewater, drinking water, and food samples contain too few organisms to use a viable plate count - used to count algal cells because algae seldom form distinct colonies on solid media

Activation of complement and inflammation - Antibody Function

- Stems of two or more IgM antibodies bind to complement protein 1 (C1), activating it to become enzymatic - begins the classical complement pathway, which releases inflammatory mediators

Serial dilution and viable plate counts - direct method requiring incubation (3)

- Stepwise dilution of a liquid culture in which the dilution factor at each step is constant. - used when microbe population is very large Viable plate count - estimation of the size of a microbial pop. based upon the # of colonies formed when diluted samples are plated.

DNA replication summary (3)

- Synthesis of leading strand proceeds continuously toward the replication fork from a single RNA primer at the origin, following helicase and the replication fork down the DNA. - Lagging strand is synthesized away from the replication fork discontinuously as a series of Okazaki fragments, each of which begins with its own RNA primer. - All primers are eventually replaced with DNA nucleotides, and DNA ligase joins the Okazaki fragments.

Tuberculosis and rifampin (3)

- TB bacterium acquired a mutation that confers resistance to rifampin - in a patient taking rifampin, the mutated cells survive, increasing the mutated gene's frequency in the population - the population evolves resistance to rifampin

Biosafety Level 3 (BSL-3) (3)

- TB, anthrax, yellow fever viruses, Rocky Mountain spotted fever - all microbe manipulations done in safety cabinets w/ HEPA filters - double sets of doors, lower air pressure in lab, HEPA-filtered air

TLR Examples (2)

- TLR3 binds to double-stranded RNA from viruses such as West Nile virus - TLR2 and TLR6 in conjunction bind to lipoteichoic acid—a component of Gram-positive cell walls

How does the 2nd line of defense differ from the first? (3)

- The 2nd line includes no barriers - instead it is composed of cells (especially phagocytes), antimicrobial chemicals (peptides, complement, interferons), and processes (inflammation, fever) - some cells/chemicals from the 1st line play roles in the 2nd line

Turbidity - indirect measurement of microbe growth

- The greater the bacterial population, the more turbid (cloudy) the broth will be - can be measured using a spectrophotometer which measures light transmitted through a culture under standardized conditions

Why are there few drugs to treat eukaryotic infections?

- There are many antibacterial drugs because prokaryotes and the eukaryotes they infect are so different. - There are FEW antifungals, antiprotozoan, and antihelmintic drugs because the microbes, LIKE THEIR HOSTS, are eukaryotic chemoheterotrophs & share many common features

Why are there may classes of antibodies? (2)

- Threats confronting the body can be extremely variable - The class involved in any given antibody immune response depends on the type of invading foreign antigens, the portal of entry involved, and the antibody function required.

Examples of Viral Infections (3)

- Tobacco mosaic virus—the first virus isolated—causes yellow discolorations of tobacco leaves. - A bacterial cell (purple) under attack by bacteriophages (pink). - A human white blood cell's cytoplasmic membrane, to which HIV (pink) is attached.

TLRs - Nonspecific Chemical Defenses Against Pathogens

- Toll-like receptors (TLRs) --> Integral membrane proteins produced by phagocytic cells - RECOGNIZE PAMPs --> Bind PAMPs --> Initiate defensive responses ----> Secretion of inflammatory mediators or interferons ----> Stimulate adaptive immune response ----> Apoptosis

3 Main Categories of Side Effects

- Toxicity - Allergies - Disruption of Normal Microbiota

Frequency of Disease

- Track occurrence of diseases using two measures - incidence, prevalence, occurrence

Disease Transmission

- Transmission is from a reservoir or a portal of exit to another host's portal of entry - 3 Groups of Transmission (contact, vehicle, vector)

Notable Spirochetes (2)

- Treponema pallidum, the agent of syphilis - Borrelia burgdorferi, the cause of Lyme disease

Placenta - Portals of Entry (4)

- Typically forms effective barrier to pathogens - Pathogens may cross the placenta and infect the fetus --> (2%) Can cause spontaneous abortion, birth defects, premature birth --> Ex: Listeria monocytogenes, Rubella virus

* Environmental factors that contribute to the activation of oncogenes

- UV light - radiation - carcinogens - viruses

Dry Heat - Heat Methods of Microbial Control (4)

- Used for materials that cannot be sterilized with moist heat - Denatures proteins and oxidizes metabolic and structural chemicals - Requires higher temperatures for longer time than moist heat - Incineration is ultimate means of sterilization

Lymphocytes (5)

- WBC that acts against specific pathogens - when resting, they're the smallest WBC - form in red bone marrow --> sites contain blood stem cells (hematopoietic stem cells), which are cells that give rise to all types of blood cells --> This is why a bone marrow transplant can restore a person's entire adaptive immune system

Temp and pH - Environmental Conditions Affecting Efficiency of Antimicrobial Agents (3)

- Warm > Cool because chems react faster at higher temps - Acid enhances antimicrobial effect of heat - SOME chem. disinfectants (household chlorine bleach) are more effective at low pH

Infection (2)

- When a pathogenic organism evades body's external defenses, multiplies, and becomes established in the body - May or may not result in disease

Communicable Disease (2)

- When an infectious disease comes from another infected host, either directly or indirectly - Ex. Influenza, herpes, and tuberculosis

What happens if lactose is absent in E. Coli?

- When lactose is absent from the cell's environment, the repressor binds to the operator, blocking the movement of RNA polymerase and halting transcription. - In this manner, E. coli cells synthesize enzymes for the catabolism of lactose only when two conditions are met: glucose is absent (CAP is bound), and lactose is present.

Bacterial Conjugation - Types of Horizontal Gene Transfer (2)

- a bacterium containing a fertility plasmid forms a conjugation pilus that transfers plasmid genes to a recipient - "F plasmid codes for pilus genes"

Mutagen

- a chemical or physical agent that interacts with DNA and increases the chance of mutations

Zone of Inhibition (4)

- a clear area where bacteria do not grow - surrounds a drug-soaked disk - measured as the diameter (to the closest millimeter) of the clear region - the bigger the zone, the stronger the agent

Elongation - second stage of bacterial translation (12)

- a cyclical process that involves the sequential addition of AAs to a polypeptide chain at the P Site 1. tRNA anticodon delivers its AA to the A site - elongation factors escort tRNA w/ a GTP molecule - energy from GTP stabilizes each tRNA as it binds to A site 2. ribozyme in the larger ribo. subunit forms a peptide bond between the terminal AA of the chain and the new AA - the polypeptide is not attached to the tRNA occupying the A site 3. using GTP energy, ribosome moves one codon down the mRNA - first tRNA moves from P site to E site - second tRNA (with attached polypeptide) moves to the vacated P site 4. ribosome releases "empty" tRNA from the E site - in cytosol, enzymes recharge the empty tRNA with another type of AA carried by that tRNA (gets it ready for use again) 5. cycle repeats, each time adding another AA, at a rate of about 15 AAs per second

Serovars (3)

- a distinct variation within a species of bacteria or virus - classification of species into strains ex. Differences in the proteins associated with bacterial flagella vary enough to allow strain classification

How do bacteria use fimbriae?

- a fimbria extends and attaches at the tip to a surface - the bacteria retracts the fimbria, pulling itself towards the attachment point

Freshwater (3)

- a hypotonic solution relative to a cell's cytoplasm - cell with a cell wall will swell to the limit - cells without a cell wall can lyse

Broths (2)

- a liquid, nutrient-rich medium used for cultivating microorganisms - used to grow microbes when fresh cultures or large numbers of cells are required

Slime Layer - glycocalyx (2)

- a loose, water-soluble glycocalyx - often sticky, they help form biofilms

Maturation - 4th Stage of Phagocytosis (2)

- a membranous organelle called a Lysosome fuses to the maturing Phagosome and adds digestive chemicals - fusion is now called a Phagolysosome

Chromosomes (3)

- a molecule of DNA associated w/ a protein In prokaryotes: typically circular; in nucleoid (in cytosol) In eukaryotes: threadlike; most visible during mitosis and meiosis

Latent Diseases (2)

- a pathogen remains inactive for a long period of time before becoming active - Ex. Herpes

Mutation (3)

- a permanent, heritable change in the nucleotide base sequences of a genome - most are harmful (deleterious) - rarely it can lead to beneficial adaptation

How could phage treatment be effective for human use? (2)

- a phage can can 99.9% of host cells in 2 hours - if the phages are carefully matched to disease-causing bacteria, the treatment can be effective without killing the body's helpful bacteria

Repression & Induction - 2nd step of inducing lac operon

- a regulatory gene outside lac produces a repressor protein that attaches to DNA at the lac operator (gene is constantly made) - its presences prevents RNA polymerase from bind to lac promoter - thus, lac is usually inactive even if CAP is present - when lactose is present, its derivative, allolactose, acts as an inducer by inactivating the repressor so that the repressor cannot bind to the operator, allowing transcription to proceed - RNA polymerase binds to promoter and transcribes the 3 lac genes - the operon has been induced

Complement (picture)

- a set of serum proteins designated numerically according to their order of discovery --> 30+ proteins: C1a, C1r, C1q, C2a, C2b, C3a, C3b - initially act as opsonins and chemotactic factors - Complement activation results in lysis of the foreign cell - Indirectly trigger inflammation and fever - Complement activation (Classical pathway & Alternative pathway)

Prodromal Period - 2nd Stage of Infectious Disease (2)

- a short time of generalized, mild symptoms (such as malaise and muscle aches) that precedes illness - Not all infectious diseases have a prodromal stage

Methylation of DNA daughter strands (2)

- an enzyme adds a methyl group for one or two bases in specific nucleotide sequences - Bacteria typically methylate Adenine bases (rarely Cytosine bases)

Broth Dilution Test (2)

- a standardized amount of bacteria is added to serial dilutions of antimicrobial agents in tubes or wells containing broth - After incubation, turbidity (cloudiness) indicates bacterial growth; lack of turbidity indicates that the bacteria were either inhibited or killed by the antimicrobial agent

Temperate (aka Lysogenic) Phages (3)

- able to incorporate into bacterial genome - doesn't immediately kill its host cell - part of Lysogeny

The human genome has how many base pairs? (3)

- about 6 Billion bp in forty-six nuclear DNA molecules - would be about 3 meters long (3 million um) if all DNA molecules were laid end to end - most of the genome is packed into a 5 um nucleus

How are B and T lymphocytes differentiated by scientists? (2)

- according to surface proteins that are part of each lymphocyte's cytoplasmic membrane - These proteins allow lymphocytes to recognize specific pathogens and toxins by their molecular shapes, and the proteins play roles in intercellular communication among immune cells

What can cause yeast infections? (2)

- acidity results in the vagina from the fermentation of carbohydrates by normal resident bacteria - if the growth of these normal residential bacteria is inhibited (ex. by antibiotic therapy) the resulting higher pH may allow yeasts to grow

Nitrogen sources (4)

- acquired from organic nutrients (NH3, ammonia) —> most photosynthetic organisms can reduce nitrate to ammonium to use for biosynthesis - inorganic nutrients (Nitrogen gas) —> few organisms that utilize nitrogen gas because it's triple-bonded and highly stable

Culture (2)

- act of cultivating microorganisms or the microorganisms that cultivated - can be grown in broths or on surfaces

Memory T Cells

- activated T cells become memory T cells - can persist in "suspended animation" for months to years in lymphoid tissue - Immediately functional upon subsequent contacts with epitope-MHC complex specific to its TCR

Alternative Pathway of Complement Activation (3)

- activation occurs independently of antibodies with the cleavage of C3 into two fragments, C3a and C3b - Triggered when activated complement proteins (C3b) bind to the surface of microorganisms - useful in the early stages of an infection, before the adaptive immune response has created the antibodies needed to activate the classical pathway

Symport proteins (6)

- active transport - coupled with a uniport channel - transport two different molecules at the same time — the molecule originally forced out is going against its concentration gradient — the other molecule brought back in with the original is forced against its c. gradient too — ATP is only used for the movement of the first molecule; it moving back in, along its gradient, supplies the energy required to force the second up/in

Antiport protein (2)

- active transport - transport two types of molecules but in OPPOSITE directions

Uniport protein (2)

- active transport - transports only one type of molecule

Plasma Cells (4)

- actively fight exogenous antigens - secrete antibodies - don't display BCRs - have extensive rough endoplasmic reticulum and many Golgi bodies involved in the synthesis, packaging, and secreting of the immunoglobulins

Specificity (2)

- adaptive immune response acts against only one particular antigen - innate gives general responses to PAMPs

Unresponsiveness to Self (2)

- adaptive immunity does not act against normal body cells --> "self-tolerant"

What is the key to enduring protection? (2)

- adaptive immunity is unresponsive to self - adaptive immunity involves immunological memory brought about by long-lived memory B and T cells

Extracellular Matrix of Biofilms (5)

- adheres cells to one another - allows attachment to a substrate - sequesters nutrients - may protects individuals in the biofilm - made of sugars, extracellular DNA, and proteins

Temperature - physical req. for microbial growth (2)

- affects 3D structure of proteins due to temp-sensitive hydrogen bonds (form low, break high)(protein denature in high heat) - lipids in membranes become rigid/fragile in low temp; too fluid at high temp (membrane can't contain cell)

Ingestion - 3rd Stage of Phagocytosis (2)

- after adhesion, pseudopods extend and surround the microbe - the pseudopods form a food vesicle around the encompassed microbe called a Phagosome

Slant Tubes (2)

- agar poured into test tube and allowed to cool at an angle - provides a larger surface area for aerobic microbial growth while the butt (yeah) of the tube remains almost anaerobic

4 Types of Vehicle Transmission

- airborne - waterborne - foodborne - bodily fluid

Review - What physical methods of microbial control denature proteins/destroy membranes?

- all moist heat (boiling, autoclave, pasteurization, ultra-high-temp sterilization) - hot air (dry heat method)

What does regulation of gene expression do? (2)

- allows cells to conserve energy - it typically halts transcription (production of mRNA) and can directly stop translation

Pentose Phosphate Pathway (4)

- alternative to glycolysis - less energy efficient - produces precursor metabolites and NADPH —> used to make DNA nucleotides, steroids, fatty acids

Length of Convalescence Period Depends On: (4)

- amount of damage - nature of the pathogen - site of infection - overall health of the patient

Hfr (high frequency of recombination) cell (4)

- an F+ cell integrates its F plasmid into its Prok. chromosome - they form pili and transfer genes more frequently than normal F+ cells - often, cell movement breaks connection and only a partial copy of DNA and F plasmid make it - recipient is recombinant BUT REMAINS F-

Eosinophilia (3)

- an abnormally high number of eosinophils in the blood - often indicative of helminth infestation - also common in patients w/ allergies

Prophage (6)

- an inactive bacteriophage - does not immediately assume control of the cell - codes for a protein that suppresses prophage genes - repressor protein renders the bacterium resistant to additional infection by other viruses of the same type - prevents further infection - part of Lysogeny

Repressible operons regulate what metabolic pathway? Depending on what? (2)

- anabolic pathways - depending on the presence of product of pathway

Prokaryotic DNA Replication (5)

- anabolic polymerization process that allows cells to duplicate its genome - a cell separates the 2 original strands and uses each as a template for the synthesis of a new complementary strand - semiconservative; each daughter DNA molecule is composed of one original strand and one new strand - bidirectional; DNA synthesis proceeds in both directions from the origin - bacteria, archaea, eukaryotes employ similar mechanisms for DNA replication

Bacterial Flagella Basal Body - structure (2)

- anchors the filament and hook to the cell walls and cytoplasmic membrane using a rod & either 2/4 rings of proteins - composed of different proteins than filament and hook

Culturing Viruses in Plants/Animals - Mature Organism Media (2)

- animal cultures can be difficult, expensive, and controversial - growing viruses that only infect humans raises more ethical complications

Antisense Nucleic Acids (5)

- another drug that blocks protein synthesis - designed to complement mRNA molecules of pathogens - block ribosomal subunits from attaching to mRNA - don't effect the human's mRNA - ex. Fomivirsen inactivates cytomegalovirus and treats eye infections

Bacitracin (2)

- antimicrobial that blocks NAG and NAM secretion from the cytoplasm - prompts cell lysis - (non beta-lactam)

Dermicidin - of sweat glands (4)

- antimicrobial/antifungal peptide - active against many Gram-negative and Gram-positive bacteria and fungi - insensitive to low pH and salt (as expected) - exact mechanism of action is unknown

Oxazolidinones (2)

- antimicrobials that stop protein synthesis by blocking Initiation of translation - used as a last-resort against Gram-positive that are resistant to other antimicrobials (including vancomycin- and methicillin-resistant Staphylococcus aureus)

praziquantel and ivermectin (2)

- antiparasitic drugs that act against the cytoplasmic membrane - change the permeability of cell membranes of several types of parasitic worms

Artificially Acquired Passive Immunity (3)

- antisera or antitoxins - medical personnel routinely harvest antibodies specific for toxins and pathogens that are so deadly or so fast acting that an individual's active immune response is inadequate - They acquire these antibodies from the blood of immune humans or animals, typically a horse

What happens to a cell that undergoes extensive damage to its membrane proteins/phospholipids? (2)

- any physical or chemical agent allows the cellular contents to leak out - if not immediately repaired, the cell will die

B Lymphocytes (4)

- arise and mature in the red bone marrow of adults - Humoral/Antibody immune responses - carry out antibody immune responses - often directed against extracellular pathogens and toxins

T Lymphocytes (5)

- arise in red bone marrow - mature in the Thymus - Cell-mediated immune responses - act against intracellular pathogens and abnormal body cells (cancer cells) - 2 groups (helper T; cytotoxic T)

Noncommunicable Diseases (3)

- arise outside hosts or from normal microbiota - not spread from one host to another, and diseased patients are not a source of contamination for others - Ex. tooth decay, acne, tetanus

substrate concentration - enzyme reaction rate factors (4)

- as substrate concentration increases, enzyme activity increases - more and more enzyme active sites bind mor and more substrate molecules - when all enzyme active sites are bound, the enzymes have reached their Saturation Point - enzyme concentration matters too; organisms regulate their metabolism by controlling the quantity and timing of enzyme synthesis

Effectiveness of Antimicrobials

- ascertained by Diffusion susceptibility test (Kirby-Bauer)

Nonspecific Chemical Defenses Against Pathogens (7)

- assist phagocytic cells either by enhancing other features of innate immunity or by directly attacking pathogens - lysozyme - defensin - Toll-like receptors - NOD proteins - interferons - complement

Adhesion - 2nd Stage of Phagocytosis (2)

- at infection site, phagocytes attach to microbes by binding their complementary chemicals (glycoproteins) - some bacteria have virulence factors that hinder adhesion by phagocytes (slippery capsules!!)

Bacterial Flagella Hook - structure (3)

- at the base, filament inserts into a curved structure (the hook) - connects filament to basal body - composed of a different protein than filament

Cytotoxic T Cells

- attack infected cells directly

How can you check that an autoclave has sterilized its contents? (5)

- autoclave tape that changes color at the right temp - chemical paper that changes color once a combo of temp/time has been reached - plastic beads that melt under proper conditions - Bacillus endospores on tape (no growth, the autoclave worked) - endospores introduced to pH color indicator post-autoclave (color change, not good; no change, good!)

6 Basic Categories of Microorganisms that Leeuwenhoek Described

- bacteria - archaea - fungi - protozoa - algae - small, multicellular animals

Difference Between Lytic Replication and Lysogeny

- bacterial genome is destroyed upon viral entry in Lytic - inactive prophage integrates with bacterial chromosome in lysogeny

Hami (2)

- barbed, hooked appendages used to securely attach archaea to substrate;each end has three arms - each archaea can have 100+

4 Types of Milk Pasteurization (know each!)

- batch (historical/old) pasteurization - flash pasteurization - ultra-high-temperature pasteurization - ultra-high-temperature sterilization

How is Selective Toxicity possible? (2)

- because of differences in structure or metabolism between the pathogen and its host - the more differences, the easier it is to discover or create an effective antimicrobial agent

How are active immune responses advantageous? (2)

- because they result in immunological memory and protection against future infections - HOWEVER they are slow

How do archaea reproduce? (3)

- binary fission - budding - fragmentation

Pentamidine and propamidine isethionate (2)

- bind to protozoan DNA, inhibiting DNA replication and RNA transcription - the protozoa cannot reproduce or metabolize

Rifampin (4)

- binds to and inhibits the action of RNA polymerase during mRNA synthesis - bind more readily to prokaryotic RNA polymerase than to eukaryotic RNA polymerase - as a result, rifampin is more toxic to prokaryotes than to eukaryotes - used primarily against species of mycobacteria

Clofazimine (2)

- binds to bacterial DNA and evidently prevents normal transcription (and DNA replication) - used primarily against species of mycobacteria

2 Types of Vector Transmission

- biological vectors - mechanical vectors

Antihistamine (2)

- block histamine receptors on blood vessel walls - can treat inflammation

* Pleconaril - prevention of virus attachment (3)

- blocks viral attachment - Tested in clinical trials to prevent Rhinovirus attachment (cause of common cold) - not FDA approved!

Decline - 4th Stage of Infectious Disease (4)

- body gradually returns to normal as the patient's immune response and/or medical treatment vanquish the pathogens - signs/symptoms subside - immune system and its products (antibodies) peak here - if the disease doesn't decline, the disease is fatal

major histocompatibility complex (MHC) proteins (8)

- body prepares for an adaptive immune response by making MHC proteins and processing antigens - Cells of adaptive immunity only recognize epitopes carried on MHC proteins - Mark self from non-self - Group of antigens first identified in graft patients - Important in determining compatibility of tissues for tissue grafting - Major histocompatibility antigens are glycoproteins found in the membranes of most cells of vertebrate animals - Hold and position antigenic determinants for presentation to immune cells - in humans, MHC is located on each copy of chromosome 6

Fever (4)

- body temp over 39.4ºC (103F) or higher is a concern - Results when pyrogens trigger the hypothalamus to increase the body's core temperature - continues as long as pyrogens are present - side effects, including malaise, body aches, and tiredness - exact mechanism unknown

Moist Heat Methods (3)

- boiling - autoclaving - pasteurization

Nutrient Agar vs. MacConkey Agar (3)

- both Gram-negative and positive grow on nutrient agar - MacConkey agar is selective! (inhibits Gram-positive) - MacConkey agar is differential! (based on lactose fermentation)

2 Processes to Catabolize Glucose

- both begin with glycolysis 1. Cellular respiration (complete breakdown of glucose to CO2 and H2O) (significant amount of ATP made) 2. Fermentation (results in organic waste products) (much less ATP than respiration)

Compare/contrast bacterial DNA and archaeal DNA (4)

- both haploid - both in nucleoid - both typically circular - Archaeal chromosomal DNA wraps around globular proteins called Histones

Neutrophils and Eosinophils (2)

- both phagocytize pathogens - both capable of Diapedesis

Mutualism (2)

- both symbionts benefit from their interaction - Ex. bacteria in your colon

Prokaryotic Ribosomes (5)

- called 70S ribosomes based on their sedimentation rate in an ultracentrifuge - extremely complex associations of ribosomal RNAs ad polypeptides - each is composed of a 30S and a 50S - 50S is composed of two rRNA molecules (23S and 5S) & 34 polypeptides - 30S is composed of one 16S rRNA & 21 ribosomal polypeptides - ribosomes of mitochondria & chloroplasts are 70S and thus considered prokaryotic (yes, even in eukaryotes!!)

Extracellular State (WHEN OUTSIDE A HOST) - of Viruses (5)

- called a "virion" - protein coat "capsid" surrounds nucleic acid - nucleic acid + capsid = "nucleocapsid" - some viruses have phospholipid Envelope - outermost layer provides protection/recognition sites for host cells

Archaeal Glycocalyx (3)

- can be composed of polysaccharides, polypeptides, or both - function at a minimum in the formation of biofilms (though no archaea has been shown conclusively to be pathogenic)

Filtration - Physical Methods of Microbial Control

- can be used to sterilize such heat-sensitive materials as ophthalmic solutions, antibiotics, vaccines, liquid vitamins, enzymes, and culture media

Ionizing Radiation - radiation mutagens (5)

- can cause cell molecules to lose electrons - these molecules become Highly Reactive Ions and Free Radicals - can combine w/ bases on DNA, causing mutations - can react w/ sugar-phosphate backbone of DNA, causing breaks in chromosomes (X-rays or Gamma rays)

Killing by Neutrophils

- can kill with/without phagocytosis - Primary "bacteria eating cell" --> first to arrive at infection site - produces chemicals from the membrane that kill nearby invaders - Generate extracellular fibers called neutrophil extracellular traps (NETs) that bind to and kill bacteria --> Unique type of cell death seen in neutrophils --> NETs composed of chromatin studded with antimicrobial proteins

Alkalinophiles

- can live in alkaline soils and water up to pH 11.5 ex. Vibrio cholerae grows best outside the body in water at pH 9.0 (causative agent of cholera)

Synthesis of acetyl-CoA - 1st stage of cellular respiration (4)

- converts pyruvic acid into acetyl-CoA - must occur prior to Kreb's cycle - occurs in cytosol of prokaryotes; matrix of mitochondria of eukaryotes - total sum of each pyruvic acid results in: 2 acetyl-CoA, 2 CO2, 2 NADH

Killing by Eosinophils (7)

- can phagocytize BUT it's not their usual mode of attack - instead they secrete antimicrobial chemicals against pathogens that are too large to ingest - attack helminths by adhering to the worm surface and secreting toxins that weaken and kill it - Lipopolysaccharide from Gram-negative bacterial cell walls triggers eosinophils to rapidly eject their mitochondrial DNA --> mitoDNA combines with previously extruded eosinophil proteins to form a physical barrier --> this extracellular structure binds to and then kills the bacteria -> first evidence that DNA can have antimicrobial activity

Differential White Blood Cell Count

- can signal signs of disease - Increased eosinophils indicate allergies or parasitic worm infection - Increased neutrophils and lymphocytes indicate bacterial disease - Increased lymphocytes indicate viral infection - increase of certain leukocytes over normal can indicate cancer - a decrease below normal can reveal immunodeficiency

**** Characteristics of Viruses (6)

- can't carry out metabolic pathways - can't grow/respond to environment - can't reproduce independently - recruit host's metabolism to increase their numbers - no cytoplasmic membrane, cytosol, or organelles, - have an extracellular and intracellular state

Basophils (2)

- capable of diapedesis but NOT phagocytic - instead, they release inflammatory chemicals

Intracellular State (WHEN INSIDE A HOST) - of Viruses (2)

- capsid (and envelope) is removed - virus without a capsid exists solely as nucleic acid

Bacteriocin Plasmids (3)

- carry genes for antibacterial protein toxins (Bacteriocins) —> kill bacterial cells of the same or similar species that lack the plasmid - a bacterium containing this plasmid can kill its competitors

Resistance (R) Plasmids (3)

- carry genes for resistance to one or more antimicrobial drugs or heavy metals - certain cells can transfer resistance plasmids to other cells ex. strains of E. Coli have acquired resistance to ampicillin, tetracyclin, and kanamycin from a strain of bacterial in the genus Pseudomonas

Prokaryotic mRNA (3)

- carry genetic info from chromosomes to ribosomes as codons - AUG start codon, sequential codons for amino acids in the (often more than one) polypeptide, and one of the stop codons - almost all prokaryotic mRNA molecules lack introns and exons!!!

Fertility (F) Plasmids

- carry instructions for conjugation (DNA transfer)

Virulence Plasmids (3)

- carry instructions for structures, enzymes, or toxins that enable a bacterium to become pathogenic - toxins, capsules, etc. ex. E. Coli can cause diarrhea when it carries plasmids that code for certain toxins

Inducible operons regulate what metabolic pathway? Depending on what? (2)

- catabolic pathways - depending on the presence of substrate of pathway

Frameshift mutagens - type of chemical mutagen (5)

- cause small insertions/deletions of DNA base pairs - these have the right chem. properties and size to slip between base pairs, producing a bulge in DNA molecule that leads to insertion/deletion ex. Acridine (dye used as mutagen in labs) ex. Benzopyrene (in smoke/soot) ex. Ethidium Bromide (dye used to stain DNA in labs)

Anthrax (3)

- caused by Bacillus anthracis endospores - endospores enter the body and reactivate, multiplying rapidly and releasing the anthrax toxin - can enter body via Respiratory, Gastrointestinal, or Cutaneous contact

Nonionizing Radiation - radiation mutagens (5)

- causes adjacent Thymine bases to covalent bond to each other, making Thymine Dimers (MOST COMMON TYPE OF MUTATION) - Thymine Dimers can hurt/kill a cell unless repaired - Pyrimidine Dimers prevents Hydrogen bonding with nucleotides - Dimers prevent replication or transcription ex. UV light

Coagulase - Extracellular Enzymes of Virulence Factors (2)

- causes blood to clot, providing a "hiding place" for bacteria inside from the immune system - Kinase degrades clot

Inhibition of Cell Wall Synthesis - 1/6 Mechanisms of Microbial Drug Action

- cell wall protects from effects of osmotic pressure - we'll see Bacterial and Fungal wall inhibition

Mycobacteria - resistance (4)

- cell walls contain lots of waxy lipid - helps survive drying - protects them from water-based chemicals - strong disinfectants or heat must be used for equipment in contact with TB patients

T lymphocytes (7)

- cell-mediated immune responses - arise in red bone marrow, mature on thymus - account for about 70% to 85% of all lymphocytes in the blood - Circulate in the lymph and blood and migrate to the lymph nodes, spleen, and Peyer's patches - Have T cell receptors (TCRs) on their cytoplasmic membrane --> Antigen-binding sites are complementary to epitopes --> Every T cell randomly chooses and combines segments of DNA from TCR genes to create a new genetic combination specific to that cell, which codes for the cell's unique and specific TCR

Competence (2)

- cells able to take up DNA from the environment are said to be Competent - results from a Transport protein in the cell wall that brings DNA into the cell

Lag Phase - 1/4 phases of microbial growth (4)

- cells adjusting to new environment - cells actively synthesize enzymes needed to utilize nutrients - number of dying cells equal number of reproducing cells - most don't reproduce immediately because they're busy making enzymes

Formed Elements

- cells and cell fragments in plasma - 3 types (erythrocytes, platelets, leukocytes)

Mucous Membrane Epithelial Shedding (2)

- cells are continually shed and replaced by Stem Cells - shedding carries attached microorganisms away

Dendritic Cells (4)

- cells of the epidermis and mucous membranes that devour pathogens - slender, fingerlike processes of dendritic cells extend among surrounding cells, forming an almost continuous network to intercept invaders - NONSPECIFIC - but are also involved in Adaptive (specific) immunity

What happens if the fever is too high? (5)

- critical proteins are denatured - nerve impulses are inhibited --> hallucinations --> coma --> death

7 Mechanisms to Maximize Growth Rate Efficiency

- cells synthesize/degrade membrane proteins continuously to manage chemical concentration in cytosol or organelles - cells often synthesize enzymes when substrate is available (ex. enzymes of beta-oxidation aren't produced if there aren't fatty acids to catabolize) - cells catabolize the most energy-efficient choice if 2+ energy sources are available (Carbs > lipids > proteins) - cells synthesize metabolites they need; cease synthesis if metabolite is available - eukaryotic cells isolate enzymes of different met. pathways within membrane-bound organelles - cells use allosteric sites on enzymes to control enzyme activity - Feedback inhibition slows/stops anabolic pathways when product is in abundance

Prokaryotic (3)

- cells that lack nuclei; their genes aren't surrounded by a membrane - reproduce asexually - found everywhere there is sufficient moisture)

Medulla of Lymph Node (3)

- central region - filters lymph - houses lymphocytes

Riboswitch - regulation of transcription (2)

- change shape in response to environmental changes (temperature or nutrient concentration) - mRNA can acts as riboswitches, folding to either favor/block translation depending on cell needs

Pyrogens (5)

- chemical that trigger hypothalamus "thermostat" to reset at a higher temp, triggering fever - Bacterial toxins - Cytoplasmic contents of bacteria released by lysis - Antibody-antigen complexes - Pyrogens released by phagocytes that have phagocytized bacteria

Semisynthetic Antimicrobials (2)

- chemically altered antibiotics - more effective, longer lasting, easier to administer than naturally occurring antibiotics

Sulfonamides (6)

- chemically very similar to para-aminobenzoic acid (PABA) - PABA is crucial for synthesis of nucleotides of DNA and RNA synthesis - As analogs of PABA, sulfonamides compete with PABA for the active site of the enzyme involved in the production of dihydrofolic acid - the less dihydrofolic acid, the less tetrahydrofolic acid (THF) - the less THF, the less DNA/RNA - end result of sulfonamide competition with PABA is the cessation of cell metabolism, which leads to cell death

Chemotactic Factors (2)

- chemicals, such as peptides derived from complement and cytokines, that attract cells - include defensins, peptides derived from complement, and chemicals called chemokines

Where do you find the DNA of prokaryotic genomes? (2)

- chromosomes - plasmids

Shapes of Bacterial Colonies (5)

- circular - rhizoid - irregular - filamentous - spindle

transport media (2)

- clinical specimen are often transported using this - media chemically formulated to maintain the relative abundance of different microbial species or to maintain an anaerobic envionment

known archaeal cells are what shapes? (4)

- cocci - bacilli - spirals - pleomorphic

Metabolism (2)

- collection of controlled biochemical reactions that take place within a microbe - ultimate function is to reproduce the organism

Lymph

- colorless, watery - Liquid with similar composition to blood plasma - Arises from fluid leaked from blood vessels into surrounding tissues - carries toxins and pathogens to areas where lymphocytes are concentrated

Etest (3)

- combines aspects of an MIC test and a diffusion susceptibility test - involves placing a plastic strip containing a gradient of the antimicrobial agent being tested on a plate uniformly inoculated with the organism of interest - After incubation, an elliptical zone of inhibition indicates antimicrobial activity, and the minimum inhibitory concentration can be noted where the zone of inhibition intersects a scale printed on the strip

Unicellular Algae (4)

- common in freshwater ponds, streams, lakes and oceans - acts as the major food source of small aquatic & marine animals - provides most of the world's oxygen as a by-product of photosynthesis - glass-like cell walls of "diatoms" provide grit for many polishing compounds

the phenol coefficient (3) - Methods to Measure Efficiency of Antimicrobial Agents

- compares a chemical's antimicrobial properties to those of phenol - a result of >1 means it's more effective - not used much anymore because many disinfectants/antiseptics are more effective than phenol

How are competence and transformation useful? (2)

- competent cells take up DNA from any donor genome - this makes them useful in genetic engineering (recombinant DNA technology)

Biofilms (6)

- complex, synergistic relationship among numerous microorganisms, often of different species - the primary residence of microorganisms in nature - CDC estimates biofilms cause up to 70% of bacterial diseases in 1st world countries (ex. healthcare-related infections such as might occur w/ implantation of medical devices) - many microbes are more harmful as part of a biofilm - develop an extracellular matrix

Bacteria (2)

- composed of a polysaccharide called "peptidoglycan" - some bacteria lack cell walls

Immunizations (2)

- composed of toxoids --> toxins that have been treated with heat, formaldehyde, chlorine, or other chemicals to make them nontoxic but still capable of stimulating the production of antibodies

Inhibition of Protein Synthesis - 2/6 Mechanisms of Microbial Drug Action (3)

- consistent supply of proteins is vital to active cell life - all cells use ribosomes to translate proteins from mRNA - antimicrobials can target prokaryotic ribosome differences (from Euk ribos)

F+ cells (3)

- contain F plasmid - have pili - serve as donors during conjugation

Selective media - 6 types of culture media (2)

- contain substances that favor or inhibit growth of particular microorganisms ex. acidic pH in right (right) mades the medium selective for fungi by inhibiting the growth of bacteria

Feedback Inhibition (4)

- controls the action of some enzymes - end-product of a series of reactions is an allosteric inhibitor of an enzyme in an earlier part of the pathway - AKA "negative feedback" - can save the cell energy

Single-Strand Repair - method of DNA Repair

- damage can't be fixed directly; cell cuts section out; uses complementary strand as a template to fill gaps - Nucleotide-Excision Repair (excision-repair enzymes) - Mismatch Repair (mismatch repair enzymes)

Susceptibility of Microbes - 3 Factors Affecting Efficiency of Antimicrobial Agents

- death rates DO vary among microorganisms and viruses - microbes fall along a continuum from most susceptible to most resistant

Refrigeration/Freezing (2)

- decrease microbial metabolism, growth, and reproduction because chemical reactions occur more slowly at low temperatures and because liquid water is not available at subzero temperatures - psychrophilic (cold-loving) microbes can still multiply & spoil taste and suitability for consumption

Antimicrobial Peptides (8)

- defensin - positively charged chains of 20 to 50 amino acids that act against microorganisms - secreted on skin; in mucous membranes; in neutrophils - triggered by sugar and protein molecules on microbe surfaces - some punch holes in cytoplasmic membranes - some interrupt internal signaling or enzyme action - some act as chemotactic factors - some assemble to form fibers and microscopic nets that ensnare invading bacteria

Hyaluronidase and collagenase - Extracellular Enzymes of Virulence Factors (3)

- degrade specific molecules to enable bacteria to invade deeper tissues - Hyaluronidase digests Hyaluronic Acid - Collagenase breaks down collagen of CT

Tissue Repair (4)

- delivery of extra nutrients and oxygen to the site of dilated BVs - if tissue contains undifferentiated stem cells, tissue can be fully restored - if fibroblasts are largely involved, scar tissue forms and inhibits normal function - cardiac and brain tissue don't replicate and can't be repaired

Dendritic Cells of Mucous Membranes (3)

- dendritic cells reside below the mucous epithelium to phagocytize invaders - able to extend cytoplasmic extensions (pseudopods) between epithelial cells to "sample" the contents of the lumen --> helps prepare adaptive immune responses against particular pathogens that might breach the mucosal barrier

Attachment of Animal Viruses (3)

- dependent on chemical attraction of viral protein and host receptor - animal viruses LACK TAILS AND TAIL FIBERS - instead they have Glycoprotein Spikes on their capsids or envelopes

HeLa cells (3)

- derived from Henrietta Lacks - no longer diploid, because they have lost many chromosomes - provide only a semistandard human tissue culture medium for studies on cell metabolism, aging, and (of course) viral infection

Diploid Cell Culture (2)

- derived from embryonic tissue (animal, plant or human) - maximum lifespan of 100 doublings - PREFERRED

Continuous Cell Culture (2)

- derived from tumor cells - infinite lifespan (neoplastic cells divide relentlessly)

Biosafety Level 4 (BSL-4) (3)

- designated for dangerous or exotic microbes that cause severe or fatal diseases in humans - ex. Ebola, smallpox, Lassa fever viruses - separate buildings or completely isolated; airlocks; all air/water is filtered; personnel in pressurized "space suits"

Lysozyme (3)

- destroys cell walls - cleaves bonds between sugar subunits of the peptidoglycan walls - resulting walls are more susceptible to osmotic shock and digestion by other enzymes within phagocytes

Sterilization (in practical terms) (3)

- destruction of ALL (harmful) microbes - includes viruses/endospores ex. steam under pressure; incineration; ethylene oxide gas

Minimum Bactericidal Concentration (MBC) Test

- determines the amount of drug required to kill the microbe rather than just the amount to inhibit it (as MIC does) - samples taken from clear MIC tubes (or, alternatively, from zones of inhibition from a series of diffusion susceptibility tests) are transferred to plates containing a drug-free growth medium - The appearance of bacterial growth in these subcultures after appropriate incubation indicates that at least some bacterial cells survived that concentration of the antimicrobial drug and were able to grow and multiply once placed in a drug-free medium - Any drug concentration at which growth occurs in subculture is bacteriostatic, not bactericidal, for that bacterium - The lowest concentration of drug for which no growth occurs in the subcultures is the minimum bactericidal concentration (MBC)

Why is it useful to estimate the # of microorganisms (measure microbial reproduction)? (4)

- determines the severity of certain infections - determines effectiveness of food preservation techniques - measures the degree of contamination of water supplies - evaluates disinfectants and antibiotics

Chronic Diseases (2)

- develop slowly (usually with less severe symptoms) and are continual or recurrent - Ex. Infectious mononucleosis, hepatitis C, tuberculosis, and leprosy are chronic diseases

Chronic Inflammation (2)

- develops slow, long-lasting - can result in tissue death, causing disease

Chemostat (2)

- device that allows researchers to continuously maintain a particular phase of microbial population growth - a continuous culture system controlled by adding fresh medium at the same rate old medium is removed ("open system")

Synthesis of Animal Viruses (3)

- different strategy depending on the nucleic acid - DNA viruses often enter the nucleus - RNA viruses often replicate in cytoplasm

Elimination - 6th Stage of Phagocytosis (4)

- digestion is not always complete - phagocytes eliminate remnants of microorganisms via exocytosis - Phagolysosome fuses with plasma membrane and expels contents - some microbial components are specially processed and remain attached to the cytoplasmic membrane of some phagocytes, particularly dendritic cells (antigen processing and presentation) --> plays a role in the adaptive immune response

3 Types of Contact Transmission

- direct - indirect - droplet

Human Acquisition of Zoonoses (3)

- direct contact with animal or its waste - eating animals - bloodsucking arthropods

3 Categories of DNA Repair

- direct repair - single-strand repair - repair of double-strand damage (highly error prone)

Nucleotide Analogs - type of chemical mutagen (2)

- directly alter structure of DNA bases ex. Nitrous acid chem. alters Adenine into Guanine so they pair with Cytosine (instead of Thymine) (base substitution mutation) (AT to GC)

Entner-Doudoroff (ED) Glycolysis Pathway (3)

- discovered only in prokaryotes - some bacteria substitute this pathway instead of the traditional glycolysis - produces only 1 ATP, NADH, and NADPH

Acute Disease (2)

- disease develops rapidly but lasts a relatively short time ex. Common Cold

Since UV light doesn't penetrate well, what is it even used for? (4)

- disinfecting air - disinfecting transparent fluids - disinfecting some surfaces (barber's shears or operating tables) - wastewater (reduces chlorine need)

Control of Healthcare-Associated Infections (7)

- disinfection - medical asepsis --> good housekeeping, handwashing, bathing, sanitary handling of food, proper hygiene, and precautionary measures to avoid the spread of pathogens among patients - surgical asepsis & sterile procedures --> thorough cleansing of the surgical field, use of sterile instruments, and use of sterile gloves, gowns, caps, and masks - isolation of particularly contagious or susceptible patients - establishment of an HAI control committee charged with surveillance of nosocomial diseases and review of control measures

Pyrazinamide (3)

- disrupts transport across the cytoplasmic membrane of Mycobacterium tuberculosis - The pathogen uniquely activates and accumulates the drug - most effective against intracellular, nonreplicating bacterial cells (UNLIKE MANY OTHER ANTIMICROBIALS)

Cytotoxic T lymphocyte, TC(CD8 cell) (4)

- distinguished by copies of its own unique TCR - distinguished by the presence of CD8 cell-surface glycoproteins - directly kill other cells - CD8 only binds to MHC I

UV light - nonionizing radiation

- does not penetrate well - 260 nm wavelength causes Pyrimidine Dimers in DNA (no replication/transcription)

Termination - last stage of bacterial translation (5)

- doesn't involve tRNA - release factors halt termination - they recognize STOP codons and modify larger ribo. subunits —> activates another ribozyme and severs the polypeptide from the final tRNA (resident of P Site) - ribosome dissociates into its subunits

small interfering RNA (siRNA) - regulation of transcription (4)

- double stranded RNA - can be complementary to mRNA, tRNA, or DNA - capable of gene silencing - used in labs to artificially regulate gene expression

Broad-Spectrum Drugs (3)

- drugs effective against many different kinds of pathogens - May allow development of secondary infections by transient pathogens or superinfections by normal microbiota - Killing of normal flora reduces microbial antagonism

Chemotherapeutic Agents (2)

- drugs that act against disease - ex. insulin, anticancer drugs, antimicrobials

Narrow-Spectrum Drugs (2)

- drugs that work against only a few kinds of pathogens - Ex. Penicillin, only effective against Gram-positive

Quinolones (4)

- drugs used to inhibit nucleic acid synthesis - inhibit DNA gyrase (bacterial enzyme necessary for correct coiling and uncoiling of replicating bacterial DNA) - typically have little effect on eukaryotes or viruses - MAY act against replication of mitochondrial DNA in some euk. (mito DNA is similar to bacterial DNA)

Dessication - Physical Methods of Microbial Control (3)

- drying - inhibits microbial growth with the removal of water - inhibits most pathogens but many molds can grown on dried raisins and apricots (<16% water content)

Endospore review (5)

- each vegetative cell transforms into one endospore - each endospore germinates to form one vegetative cell - it's a defensive strategy against unfavorable conditions - difficult to kill so they're a big concern - anthrax, tetanus, and gangrene

Metronidazole (Flagyl) (4) - toxicity of drugs

- effective against anaerobic protozoa and bacteria - may cause "black hairy tongue" - harmless/temporary - breakdown products of hemoglobin accumulate in papillae of tongue

Electron carrier molecules (2)

- electrons rarely exist freely in cytoplasm; instead orbit atomic nuclei - therefore, cells use electron carrier molecules to carry electrons from one location in a cell to another

Eukaryotes use miRISC for: (5)

- embryogenesis - cell division - apoptosis (programmed cell death) - blood cell formation - cancer development

Energy-conserving stage (3)

- energy products created during this stage - 2 NADH and 4 ATP created - 2 pyruvic acid are formed

Electromagnetic Radiation (2)

- energy without mass traveling in waves at the speed of light - released from atoms that have undergone internal changes

What does the increased temperature of a fever do? (5)

- enhances interferons - inhibits growth of some microbes - enhances phagocytes - enhances lymphocytes of adaptive immunity - enhances tissue repair process

Margins of Bacterial Colonies (5)

- entire - undulate - lobate - curled - filiform

Genome (2)

- entire genetic complement - includes both 1) genes and 2) nucleotide sequences that connect genes to one another

How do envelopes provide protection to viruses from the immune system? (2)

- enveloped viruses are carrying membrane from host cells - thus are more chemically similar to the host

Which white blood cells DON'T kill using phagocytosis? (3)

- eosinophils - NK (natural killer) cells - neutrophils

Microbial Antagonism/Competition (2)

- established microbiota use up available nutrients and space, reducing the ability of arriving pathogens to colonize - LACK of this could cause Candida albicans to grow prolifically, producing an opportunistic vaginal yeast infection

Prions - resistance (4)

- more resistant than any cell or virus - requires 482 C for hours to denature - infectious proteins - cause degenerative diseases of the brain

Gaseous Agents - Antimicrobial Chemicals (5)

- ethylene oxide, propylene oxide, beta-propriolactone - denatures proteins - sterilization of heat/water-sensitive objects; high activity - used to sterilize large objects (autoclaves and spaceships) - highly explosive, highly poisonous, carcinogenic

Occurrence - Frequency of Disease (2)

- evaluated in terms of frequency and geographic distribution - endemic, sporadic, epidemic, pandemic

Metabolic Processes Guided by 8 Elementary Statements

- every cell acquires nutrients - Required energy comes from light or the catabolism of nutrients - Energy is stored in ATP - Enzymes catabolize nutrients to form precursor metabolites - Precursor metabolites, energy from ATP, and enzymes are used in anabolic reactions - Enzymes + ATP form macromolecules in "polymerization" reactions - Cells grow by assembling macromolecules into cell structures (ribosomes, membranes, cell walls, etc.) - Cell reproduce when they've doubled in size

Complex media - 6 types of culture media (4)

- exact chem comp is unknown - nutrients commonly derived from breakdown of soy, beef, yeast and proteins - supports growth of a wide variety of microorganisms - useful when sample nutritional needs are unknown

Induction (2)

- excision of a prophage from the host chromosome - afterwards, prophage reenters lytic phase

Types of Antigens (3)

- exogenous - endogenous - autoantigens

Why are zoonoses difficult to eradicate? (4)

- extensive animal reservoirs are often involved - the larger the animal reservoir (the great # and types of animals infected); the greater contact between humans and the animals - the most difficult and costly it is to eradicate - Ex. rabies transmission can be limited by vaccinating domestic pets

What can cause a protein's shape to change?

- extreme conditions (heat/chemicals/radiation) break the Hydrogen or Disulfate bonds between amino acids - denaturation occurs

Physical Methods of Microbial Control (5)

- extremes of heat/cold - desiccation - filtration - osmotic pressure - radiation

How are passive immune responses advantageous? (2)

- fast - but do not confer immunological memory because B and T lymphocytes are not activated

Ames test

- fast, inexpensive method for screening mutagens

Organic Materials - Environmental Conditions Affecting Efficiency of Antimicrobial Agents (4)

- fat, feces, vomit, blood, intracellular matrix of biofilms - all interfere with penetration of heat, chems, some radiation - some materials inactivate chemical disinfectants - CLEAN OBJECTS BEFORE STERILIZATION SO AGENTS CAN WORK PROPERLY

What are the most suitable eggs for culturing? (2)

- fertilized chicken eggs that contain a fertilizing embryo - embryonic tissues (called "membranes") are ideal inoculation sites

Elevation of Bacterial Colonies (5)

- flat - raised - convex - pulvinate - umbonate

Bacterial Chromosomal DNA (2)

- folded into loops that are 50,00 - 100,000 bp long - held in place by protein and RNA molecules

Class II MHC Protein

- found ONLY on antigen-presenting cells (APCs) in addition to MHC I - found on B lymphocytes, macrophages, dendritic cells - nonspecific; can bind thousands of different epitiopes (unlike enzymes)

Class I MHC Protein

- found on the cytoplasmic membranes of all human cells except red blood cells - found on all nucleated cells - nonspecific; can bind thousands of different epitiopes (unlike enzymes)

Aseptic (2)

- free of all pathogens ex. surgery prep; hand-washing; flame/autoclave sterilization of lab equipment

Inhibition of Synthesis of Fungal Walls (4)

- fungal cell walls have a sugar (1,3-d-glucan) that's not found in mammalian cells - "echinocandins" are antifungal drugs that inhibit enzyme synthesis of glucan - w/o glucan, fungal cells can't make cells walls and will lyse - ex. Caspofungin

Review - Even using chemical methods, what are still difficult to kill?

- fungal spores - protozoan cysts - bacterial endospores

How might fungal viruses propagate? (2)

- fusion of cells is a common part of fungal life cycle - viral infection can easily be propagated by the fusion of an infected fungal cell with an uninfected one

Glycocalyx (6)

- gelatinous, sticky substance that surrounds the outside of the cell - "sweet cup" - may be composed of polysaccharides, polypeptides, or both (produced internally and extruded to surface) - protect cells from drying (desiccation) - contribute to biofilms - 2 types (capsule and slime layer)

Stem Cells

- generative cells capable of dividing to form daughter cells of various types

* Protooncogenes (3)

- genes that promote cell growth and division - Uncontrolled activation of oncogenes can lead to cancer - inactivation of oncogene repressors can lead to cancer

Point Mutation (2)

- genetic mutation affecting only one base pair in a genome - most common

External Structure of Archaea (4)

- glycocalyces - flagella - fimbriae - hami

Capsule - glycocalyx (3)

- glycocalyx composed of organized repeating units of organic chemicals firmly attached to the cell's surface - contains chemicals to help avoid detection by defenses of host; more able to cause disease — unencapsulated strains don't cause disease because they're quickly destroyed

Methane (4)

- greenhouse gas that traps heat - 25 times as potent than carbon dioxide - can be used to digest sludge for sewer treatments - can be burned to heat buildings and generate electricity

Polyenes (2) - disruption of cytoplasmic membranes

- group of antifungal and antiprotozoan drugs - ex. Nystatin, amphotericin B

Arrangements of Basilli (5)

- single basillus - diplobacilli - streptobacilli - palisade (Corynebacterium uses snapping division) - V-shape (Corynebacterium)

The Lacrimal Apparatus (5)

- group of structures that produce and drain away tears - tears either evaporate or drain into small lacrimal canals, which carry them into nasolacrimal ducts that empty into the nose --> tears join the nasal mucus and flow into the pharynx, where they are swallowed - Blinking spreads tears and washes surface of the eye - Lysozyme in tears destroys bacteria

all living things share at least 4 processes of life:

- growth - reproduction (the ability to change in response to environment; not all are capable of taxis) - responsiveness - metabolism

Site to be Treated - 3 Factors Affecting Efficiency of Antimicrobial Agents (4)

- harsh chems/extreme heat can't be used on humans, animals, fragile objects - medically, method/level of microbial control is chosen based on site of procedure (as it greatly affects the potential for subsequent infection) - penetration of outer defenses calls for sterilized equipment (scalpels through skin) - disinfection may be adequate for mucous membrane contact

Subacute Disease (2)

- have durations and severities that lie somewhere between acute and chronic - Ex. Subacute bacterial endocarditis, a disease of heart valves

Similarities between Prokaryotic and Eukaryotic DNA Replication (3)

- helicases and topoisonmerases unwind DNA - protein molecules stabilize single-strand DNA - molecules of DNA polymerase synthesize leading/lagging strands simulataneously

Heat-Related Methods - Physical Methods of Microbial Control (3)

- high temps denature proteins, degrade cytoplasmic membranes, cell walls, and nucleic acids - can be used for sterilization - Thermal Death Point and Thermal Death Time

Direct Repair - method of DNA Repair (3)

- highly accurate as they only fix one strand and the right base can be ascertained from the complementary strand - Base-Excision Repair (recognizes specific incorrect base and removes/replaces only that base) - Light Repair

How do humans have species resistance? (5)

- human cells and basic physiological processes are incompatible w/ structures/physiology or most plant/animal pathogens - either the receptors that the pathogens need don't exist in the human body - or the pH/temp is incompatible with pathogen requirements - Ex. humans are resistant to the Tobacco Mosaic Virus (which only affects tobacco plants) - Ex. Feline Immunodeficiency Syndrome attaches to receptors only found on cats' cells

Review - list some chemoheterotrophs. What does that mean?

- humans, animals, fungi, protozoa, helminths - obtain energy from catabolism of nutrients from other organisms - obtain carbon from other organisms

How are the antiparallel strands of a DNA helix held together?

- hydrogen bonding between complementary bases A-T base pair (DNA) G-C base pair (DNA & RNA) A-U base pair (RNA)

Uncoating (4)

- if a virus penetrates a host cell with its capsid intact, the capsid must be removed before replication can continue - poorly understood - some are uncoated in vesicles by enzymes - some are uncoated by enzymes in cell cytosol

Disease

- if an infection of a pathogen alters normal body function - any change from a state of health - AKA "morbidity"

BCR

- immunoglobulin made of 6 polypeptide chains - 2 identical, long heavy chains and 2 identical, short light chains form two arms that extend outside the cell - 2 additional chains anchor the BCR into the membrane (transmembrane portion)

Antibodies (3)

- immunoglobulins similar to BCRs - Secreted by activated B cells called plasma cells - Identical antigen-binding sites and antigen specificity as the BCR of the activated B cell

Memory (3)

- immunological memory for specific pathogens --> adapts to respond faster and more effectively in subsequent encounters with a particular type of pathogen or toxin - innate does NOT do this

Culturing Viruses in Mature Organisms

- in bacteria - in plants/animals

On the skin, where are bacteria particularly abundant? (3)

- in crevices around hairs - in the ducts of glands - they're usually nonpathogenic

Naturally Acquired Passive Immunity (4)

- in the womb, IgG molecules cross the placenta from the mother's bloodstream - children receive secretory IgA in breast milk - a mother provides her baby with antibodies that protect it during its early months - baby is not actively producing its own antibodies

gas vesicles (2)

- inclusions that store gases in protein sacs and buoy cells to the surface and into light needed for photosynthesis - used by many aquatic cyanobacteria (blue-green photosynthetic bacteria)

pH - enzyme reaction rate factors (2)

- increasing pH (the more alkaline), increasing enzyme activity (until denaturation occurs) - remember that enzymes typically have an optimal pH, at which point enzymatic activity reaches a maximum

cold enrichment (2)

- incubation of a specimen in a refrigerator to enhance the growth of cold-tolerant species - uses a selective media

lactose (lac) operon of E. Coli (2)

- inducible operon - includes: promoter, operator, and 3 genes involved in the transport/catabolism of lactose (disaccharide sugar)

Culturing Viruses in Embryonated Chicken Eggs (6)

- inexpensive - eggs are the largest of cells - eggs are free of contaminating microbes - contain a nourishing yolk (which makes them self-sufficient) - virus is injected into embryonic tissue at sites best suited for each virus's replication - vaccines can be prepared in eggs

Describe ideal microbial agents. (4)

- inexpensive - fast-acting - stable during storage - capable of controlling microbial growth while being harmless to humans, animals, and objects

Secondary Infection (2)

- infections that follow a primary infection - often by opportunistic pathogens

Viroidlike agents (3)

- infectious, pathogenic RNA particles that lack capsids but do not infect plants - affect some fungi - (They are not called viroids because they do not infect plants.) - don't cause animal diseases

Mechanisms of Microbial Drug Action (6)

- inhibition of cell wall synthesis - inhibition of protein synthesis - disruption of cytoplasmic membrane - inhibition of general metabolic pathways - inhibition of DNA/RNA (nucleic acid) synthesis - inhibition of pathogen's attachment or entry into host cell

Primary Infection

- initial infection within a given patient

Outer Membrane of Gram-negative bacterial cell (4)

- inner layer is a bilayer of phospholipids and proteins - outer layer is Lipopolysaccaride (LPS) - outer membrane can impede treatment of disease — outer membrane prevents drugs accessing the peptidoglycan cell wall of the bacteria, not allowing it to be destroyed by antibiotics

Phosphorylation (4)

- inorganic phosphate is added to a substrate - process can be done 3 ways ex. ADP has 2 phosphate groups Cells phosphorylate ADP to form ATP, which has 3 phosphate groups

What are examples of RNAs and polypeptides needed continuously by the cell? (3)

- integral proteins in the membrane - structural proteins of ribosomes - enzymes of glycolysis

Inflammatory Response - 2nd Line of Defense (2)

- internal - composed of protective cells, bloodborne chemicals, processes that inactivate/kill invaders

Cytoskeleton (5) (longish)

- internal scaffolding composed of 3-4 types of protein fibers - one type of fiber wraps around cell equator and divides the cell in two - another type forms a helix down length of cell and appear to delegate orientation and deposition of NAG-NAM sugars (determines cell shape) - other fibers keep DNA molecules segregated to areas within bacterial cells - Spiroplasm uses contractile elements of its cytoskeleton to for locomotion (no flagella)

Does the body use cell-mediated immune responses to fight intracellular OR extracellular pathogens? (4)

- intracellular pathogens! - abnormal body cells (cancer) - intracellular parasitic protozoa - intracellular bacteria

Collecting from stomach

- intubation; insert tub through nostril, down into stomach

Energy-investment stage - glycolysis (2)

- invest 2 ATP, glucose phosphorylated twice - Glucose becomes fructose 1,6-biphosphate

Analytical Epidemiology (5)

- investigates a disease in detail, including analysis of data acquired in descriptive epidemiological studies, to determine the probable cause, mode of transmission, and possible means of prevention of the disease - may be used in situations where it is not ethical to apply Koch's postulates --> analytical epidemiological studies indicate that HIV causes AIDS and that it is transmitted primarily sexually - retrospective --> they attempt to identify causation and mode of transmission after an outbreak has occurred

Eosinophils (3)

- involved in defending the body against parasitic worms - present in large number during many allergic reactions --> exact function in allergies is disputed

bacterial growth media is used for: (5)

- isolation of microbial strains - maintenance of microbial collections - aid in identification - assists in diagnosis - find effective antimicrobial drugs

Negative (Indirect) Selection - methods to recognize mutants

- isolation/culture of an auxotroph

What happens when any nucleated cell synthesizes proteins? (3)

- it displays epitopes from them in the antigen-binding grooves of MHC class I molecules on its cytoplasmic membrane - Thus, when viruses are replicated inside cells, epitopes of viral proteins are displayed on the host cell's surface - active Tc cell binds to an infected cell via its TCR, which is complementary to the MHC I protein-epitope complex, and via its CD8 glycoprotein, which is complementary to the MHC class I protein of the infected cell

the in-use test (5) - Methods to Measure Efficiency of Antimicrobial Agents

- it's a more realistic (time-consuming) test - Swabs taken from objects before and after application of disinfectant or antiseptic - Swabs inoculated into growth medium and incubated - Medium monitored for growth - Accurate determination of proper strength and application procedure for each specific situation

Archaea (3)

- lack "peptidogglycan" and instead are composed of other chemicals - often found in extreme environments - no known archaea cause diseases in humans

F- cells (2)

- lack F plasmid - don't have pili

Archaea cell walls (9)

- lack peptidoglycan - composed of specialized proteins or polysaccharides - maintain electrical and chemical gradients; control passage of substances in/out - Gram-negative archaea have an outer layer of protein (instead of phospholipids) - Gram-stain colors are the same as bacteria (pink, negative; purple, positive) - typically spherical or rod-shaped (needle-like, rectangular and square can exist) - lipids use stronger Ether linkages between branches of hydrocarbons and glycerol (bacteria use Ester) —these links allow archaea to survive extreme environments

Survey of Archaea (3)

- lack peptidoglycan in cell walls - cytoplasmic membrane lipids have branched or ring-form hydrocarbon chains (bacteria membrane lipids are straight chains) - AUG codon codes for methionine (it's the initial amino acid in their polypeptide chains)

Monocyte

- large agranulocytes with slightly lobed nuclei - leaves the blood and matures into macrophages

Kreb's Cycle - 2nd stage of cellular respiration (3)

- large amounts of energy remains in bond of acetyl-CoA - Kreb's cycle transfers much of this energy to the coenzymes NAD+ and FAD - occurs in cytosol of prokaryotes; matrix of mitochondria in eukaryotes

Size of Antigens

- larger molecules with molecular masses between 5000 and 100,000 daltons are better antigens - smaller molecules (>5000 daltons) evade detection, making for poor antigens - can bind to carrier molecules (often proteins) and become antigenic and stronger - Ex. penicillin is small but can bind and become antigenic

Antigen-binding groove (4)

- lies between two polypeptides that make up an MHC - antigens bind here - inherited variations in AA sequences modify the shape of this groove --> determine which epitopes can be bound and presented

Mucous Membranes (4)

- line all body cavities open to environment - 2 distinct layers: epithelium and deep connective tissue that supports the epithelium - NONSPECIFIC - limit infection both physically and chemically

polyhydroxybutyrate (PHB) (3)

- lipid polymer used as a carbon storage molecule and energy source by Gram-negative bacteria - long chains of PHB accumulate as inclusion granules in the cytoplasm - slight chemical modifications of PHB produces biodegradable plastic

Examples of PAMPs (3)

- lipopolysaccharide - peptidoglycan - flagellin

Plasma (4)

- liquid portion of blood - most water - contains electrolytes (ions), dissolved gases, nutrients, and a variety of proteins - Includes iron-binding compounds, complement proteins, and antibodies

Cytosol (4)

- liquid portion of cytoplasm; mostly water - contains dissolved/suspended substances like ions, carbs, proteins (mostly enzymes), lipids, and wastes - nucleoid is here (prokaryotes store their DNA in nucleoid) - inclusions are found here

Electron Transport Chain - 3rd stage of cellular respiration (5)

- located in cristae of eukaryotic mitochondria; cytoplasmic membrane of prokaryotes - most significant ATP production occurs because of ETC FUNCTION (not chain itself) - carrier molecules pass electrons down to final electron acceptor - energy from electrons pumps protons across membrane, establish a proton gradient - proton gradient is used to power Chemiosmosis, which produces the majority of ATP

Flagella (4)

- long structures that extend through glycocalyx to propel the cell - NOT all bacteria have flagella; when they do, they're very similar - 3 parts to structure (filament, hook, basal body) - may have different arrangements

Bacterial Flagella Filament - structure (4)

- long, hollow shaft - extends out of cell into environment - no membrane covers a filament of prokaryotic flagellum* - composed of many identical globular protein molecules called Flagellin

Secondary Lymphoid Organs

- lymph nodes - spleen - tonsils - mucosa-associated lymphatic tissue (MALT)

Translation (2)

- mRNA --> proteins (polypeptides) - RNA molecules in ribosomes that convert their DNA info (mRNA) and synthesize polypeptides

Alternative Splicing (2)

- major advantage to splicing - it's the ability to form multiple proteins from one gene ex. you could have 4 exons Protein A joins all 4 together Protein B joins only the first and last Protein C joins the the middle two exons ETC

Gross Mutations (5)

- major change in the nucleotide sequence of DNA - inversion (bases switching places ex. ELK to KLE) - duplication (codons duplicated) - transpositions (codons moving order in a sequence) - large insertions/deletions

Why is taxonomic grouping of infectious disease difficult? (2)

- many different pathogens may cause a disease - Ex. some Gram-positive bacteria, Gram-negative bacteria, protozoa, fungi, DNA viruses, and RNA viruses can cause pneumonia

Why are parasitic worms studied by microbiologists? (2)

- many parasitic worms causes diseases studied by early microbiologists so many classes/books feature them today - laboratory scientists diagnose infections of para. worms by finding microscopic eggs and immature stages in blood, fecal, urine and lymph specimens

Animal Reservoirs of Infection

- many pathogens that normally infect either domesticated or sylvatic (wild) animals can also infect humans - Zoonoses - Humans are usually dead-end host to zoonotic pathogens

Makeup of Enzymes (4)

- many proteins enzymes are complete in themselves - others are composed of both protein and nonprotein portions - Apoenzymes - Holoenzymes

Malignant Tumors (2)

- mass of neoplastic cells that invade neighboring tissue - can metastasize to cause tumors in distant organs or tissues

Benign Tumors (2)

- mass of neoplastic cells that remain in one place and are generally not harmful - noninvasive benign tumors can be painful as they take up space and nutrients

Superinfections

- may result from the use of antimicrobial drugs that, by inhibiting some resident microbiota, allow others to thrive in the absence of competition - not limited to health care settings

Lipid A (endotoxin) (2)

- may trigger fever, vasodilation, inflammation, shock and blood clotting in humans - killing large numbers of Gram-negative bacteria in a short period of time is dangerous for the patient

3 Types of Media for Culturing Viruses

- media consisting of mature organisms (bacteria, plants, or animals) - embryonated (fertilized) eggs - cell cultures

Synergistic relationships - assoc. of microbes

- members of the association cooperate such that each receives benefits that exceed those if it lived by itself, though each could live separately

Endogenous HAIs (3)

- members of the normal microbiota can become opportunistic pathogens as a result of hospitalization or medical treatments such as chemotherapy - arise from normal microbiota within the patient that become pathogenic because of factors within the health care setting - an infection arising within a patient from opportunistic pathogens

Besides inducible and repressible operons, what else can be used to regulate the transcription of polypeptides? (3)

- microRNA (eukaryotic) - small interfering RNA - riboswitches

Virus (3)

- minuscule, acellular infectious agent having either DNA or RNA - causes many infections of humans, animals, plants, and bacteria - they cause most of the disease that plague the industrialized world

Lysogeny (4)

- modified replication cycle - Infected host cells grow and reproduce normally for generations before they lyse - called "Temperate" or "Lysogenic" phages - ex. Lambda Phage

Antigens (2)

- molecules the body recognizes as foreign and worthy of attack - Lymphocytes bind to antigens and can then trigger adaptive immune responses

Nucleotide (2)

- monomer of a nucleic acid - composed of a nucleoside and a phosphate

* Semisynthetic derivatives of beta-lactams (5) - inhibit bacterial cell walls

- more stable in acidic environments - more readily absorbed - less susceptible to deactivation - more active against different types of bacteria - ex. methicillin, dicloxacillin

flash pasteurization (4)

- most common; modern - milk flows through heated tubes - 15 seconds at 72 C; then rapid cooling - effectively destroys all pathogens

Why is agar a useful substance in the microbiology lab? (4 reasons; 6 lines)

- most microbes can't digest agar - powdered agar dissolves at 100 C (most nutrients remain undamaged at this temp) - agar solidifies as temps below 40 C (temp sensitive nutrients can be added w/o harm to cooling agar) (cooling liquid agar can be poured over most bacterial cells w/o harming them ex. pour plate) - solid agar doesn't melt below 100 C (can culture some hyperthermophiles)

Erythrocytes (2)

- most numerous of the formed elements - Carry oxygen and carbon dioxide in the blood

Glycolysis (5)

- most organisms follow the EMP (Embden-Meyerhof-Parnas) pathway of glycolysis - first step in releasing the energy of glucose, in which a molecule of glucose is broken into two molecules of pyruvic acid and results in a small amount of ATP production - occurs in cytosol of most cells - splits a 6-carbon glucose into two 3-carbon sugar molecules - 3 stages, ten steps

Illness - 3rd Stage of Infectious Disease (4)

- most severe stage of an infectious disease - signs/symptoms most evident here - Typically, the patient's immune system has not yet fully responded to the pathogens, and their presence is harming the body - usually when a physician first sees the patient

Humoral Immune Response (3)

- mounted against exogenous pathogens and toxins - Activates only in response to specific epitopes - 2 types (T-dependent; T-independent)

Function of Bacterial Flagella (4)

- movement - Hydrogen ion flow through cytoplasmic membrane powers the rotation - 60 cell lengths per second; 100,000 rpm - light/chemical receptors on cell surface signal flagella to adjust speed and direction

Chemotaxis - 1st Stage of Phagocytosis (3)

- movement of a cell towards (positive chemotaxis) or away from (negative chemotaxis) a chemical stimulant - phagocytes use pseudopods to crawl toward microorganisms at a site of an infection - microbial secretions, parts of cells, components of damaged tissue, leukocytes and chemotactic factors attract phagocytes

Secondary Response (4)

- much faster and more effective than the primary response --> Because many memory cells recognize and respond to the antigen - subsequent exposure directly stimulates a population of memory cells, which proliferate and differentiate rapidly into plasma cells without having to be activated by antigen-presenting cells - Newly differentiated plasma cells produce large amounts of antibody within a few days

2 Examples of Mucous Membrane Chemicals

- mucus contains antimicrobial peptides - Nasal mucus also contains lysozyme

Epidermis

- multiple layers of tightly packed cells that form a physical barrier to most bacteria, fungi, and viruses - Few pathogens can penetrate these layers - Shedding of dead skin cells removes microorganisms - Epidermal dendritic cells phagocytize pathogens

auxotroph

- mutant that requires different nutrients than its wild-type phenotype ex. a bacterium has lost the ability to synthesize tryptophan and now must acquire it from the environment. The bacterium is auxotrophic for this AA. Culturing a tryptophan auxotroph without tryptophan will fail.

Naked viruses are more stable outside a host than are enveloped viruses, but they're still in danger. Why? (2)

- naked viral proteins are exposed to the environment - therefore they're more susceptible to recognition & attack from the immune system once inside a host

Collecting blood (2)

- needle aspiration from vein - anticoagulants in the transfer tube

Glycolysis results in: (4)

- net gain of 2 ATP molecules - 2 NADH molecules - 2 precursor metabolite pyruvic acid - 2 H2O molecules

5 Phagocytes

- neutrophils - eosinophils - dendritic cells (ch. 16) - macrophages - monocytes

Review - What are the first phagocytes to arrive at the site of infection? (3)

- neutrophils - followed by monocytes - monocytes leave the blood and become wandering monocytes (major component of pus)

Prokaryotes (8)

- no nucleus; carry DNA in nucleoid found in cytosol - are able to undergo transcription and translation simultaneously because of it - much smaller than eukaryotes - no membranous organelles - single, circular DNA molecule - simple structure - reproduce asexually - found everywhere there is sufficient moisture

Inflammation (3)

- nonspecific response to tissue damage (heat, chems, UV sunburn, abrasions, cuts, pathogens) - Characterized by redness, heat, swelling, and pain - 2 types (acute & chronic)

Viruses (2)

- not seen until the electron microscope was invented in 1932 - all are acellular (not composed of cells) parasites composed of small amounts of genetic material (either DNA or RNA) surrounded by a protein coat

Fungal viruses (3)

- not well studied - have no extracellular state (differs from animal/bacteria viruses here) --> possibly due to thick fungal cell wall

How do insertions/deletions cause frameshift mutations? (3)

- nucleotide triplets following the mutation are displaced - new sequences are created that result in vastly altered polypeptide sequences - frameshift mutations affect a cell more than substitutions because a frameshift affects all codons subsequent to the mutation

Eukaryotes (4)

- nucleus - membrane-bound organelles - much larger and complex than prokaryotes - multiple, linear DNA molecules

Inclusions (3)

- nutrient storage deposits often found in bacterial cytosol - chemicals are taken in and stored when abundant to be utilized later - the presence of specific inclusions is diagnostic for several pathogenic bacteria

Death Phase - 4/4 phases of microbial growth (2)

- nutrients depleted - more cells dying than reproduced

5 groups based on oxygen requirements

- obligate aerobes (require oxygen) - obligate anaerobes (oxygen is deadly) - faculative anaerobes - aerotolerant anaerobes - microaerophiles

Anaerobic media - 6 types of culture media (2)

- obligate anaerobes require special culture conditions to protect their cell from free oxygen - contains compounds (sodium thioglycolate) that chemically combine with free oxygen and remove it from the medium

Spontaneous Mutations (3)

- occur naturally during life - result from errors in replication/repair - can result from recombination

Base-substitution mutations (3)

- occur when a single nucleotide replaces another in the DNA sequence - Silent, Missence, Nonsense

Snapping Division - variation of binary fission (4)

- occurs in some Gram-positive bacilli - only the inner portion of the cell is deposited across the dividing cell - as the cell grows, tension causes the outer wall to break open at the weakest point - daughter cells remain hanging together, held at an angle by the hinge-like outer wall remaining

Self-Termination of Transcription - 1/2 types of termination of bacterial transcription (5)

- occurs when RNA polymerase transcribes a Terminator sequence of DNA composed of two regions: 1) area that is symmetrical in Guanine and Cytosine bases (their 3 Hydrogen bonds make unwinding more difficult) - this 60-second pause allows the RNA to hydrogen bond its own symm. sequences, putting tension on the union of RNA polymerase the DNA 2) followed by an area rich in Adenine bases (back to 2 H bonds that can't withstand the new tension) - RNA transcript breaks away from the DNA, releasing RNA polymerase

Missense Mutation - type of base-substitution mutation (3)

- occurs when base-substitution causes a single AA to be changed - changes the codon from one AA to a different AA - can be harmful/neutral/beneficial depending on location of mutation

Nonsense Mutation - type of base-substitution mutation (2)

- occurs when the base substitution causes a codon to become a STOP codon - harmful bc they lead to the premature termination of the protein

Silent Mutation - type of base-substitution mutation (3)

- occurs when the base substitution produces no change in the AA sequence of the resulting protein - 1/3 of all base-sub mutations are Silent due to the overlapping nature of DNA - affect Genotype (NOT phenotype) because there's no AA seq. change

Bacteria without cell walls were often mistaken for viruses because: (3)

- of their small size - their lack of walls ex. Mycoplasma pneumoniae

batch pasteurization (2)

- old/historical method - 30 minutes at 63 C

Antiparallel DNA strands (6)

- one DNA strand runs 5 ' to 3 ' - the other runs 3' to 5 ' - the base pairs extend into the middle of the molecule like a spiral staircase - hydrophobic bases are tucked inside - hydrophilic sugars and phosphates are outside - ***this explains the double helix structure of cellular DNA

How does soap work? (5)

- one end of soap is composed of fatty acids and therefore hydrophobic - hydrophobic end breaks down oil deposit - other end of soap is negatively charges and therefore hydrophilic - hydrophilic end attracts water molecules - both work together to form oily water droplets better washed away

membrane attack complex (MAC) (4)

- one end product of a full cascade - forms a circular hole in a pathogen's membrane - production of numerous MACs leads to lysis of the pathogen - bacterium causing gonorrhea is particularly sensitive to MACs

antagonistic relationship - associations of microbes (2)

- one microbe harms/kills another organism ex. virus (require host cells in order to replicate and almost always kill the host)

Commensal relationship - assoc. of microbes

- one organism benefits from another without affecting it

Commensalism (2)

- one symbiont benefits without significantly affecting the other - Ex. mites in human hair follicles

Amensalism (3)

- one symbiont is harmed by a second symbiont - the second is neither harmed nor helped by the first - Ex. the fungus Penicillium produces penicillin; penicillin inhibits nearby bacteria; bacteria don't affect fungus

Processing Exogenous Antigens

- only APCs (usually dendritic cells) process exogenous antigens 1. dendritic cell phagocytizes an invading pathogen and clips the proteins into segments, producing peptide epitopes within a phagolysosome 2. Another vesicle, already containing MHC class II molecules in its membrane, fuses with the phagolysosome. MHC II molecules bind complementary epitopes 3. vesicle then fuses with the cytoplasmic membrane 4. results in MHC II-epitope complexes on the cell's surface 5. Empty MHC II molecules (those not bound to epitopes) are not stable on a cell's surface; they degrade.

Specialized Transduction (4)

- only certain host sequences are transferred from donor host to recipient host - in nature, important for transferring genes encoding certain bacterial toxins into cells that would otherwise be harmless ex. diphtheria, scarlet fever - can transfer antibacterial resistance

Killing by Natural Killer Lymphocytes (5)

- only lymphocyte involved in innate immunity - secretes toxins onto the surface of virally infected cells and tumors (neoplasms)] --> Triggers apoptosis and cell death - they ID and spare normal body cells because they have membrane proteins similar to those on NK cells - "NK" comes from the fact that NK cells kill other cells unless they receive an inhibitory signal

* Viruses cannot reproduce independently. Viruses are dependents of hosts' ___ and ___ to produce new ___.

- organelles - enzymes - virions

4 toxic forms of oxygen

- singlet oxygen - superoxide radicals - peroxide anion - hydroxyl radical (**we're focusing on these two in class)

Symbiotic relationships - assoc. of microbes (2)

- organisms live in close nutritional or physical contact that they become interdependent - the members rarely (if ever) live outside the relationship

Chemotrophs - sources of energy for cells (2)

- organisms that acquire energy from redox reactions involving inorganic and organic chemicals - reactions are either aerobic respiration, anaerobic respiration, or fermentation depending on the final electron acceptor

Heterotrophs - sources of carbon for cells (2)

- organisms that catabolize reduced organic molecules (proteins, carbs, amino acids, fatty acids) they acquire from other organisms ex. fungi and most animals

Autotrophs - sources of carbon for cells (3)

- organisms that make organic compounds from inorganic sources of carbon (most often carbon dioxide) - they "feed themselves" and don't rely on other organisms for carbon ex. Algae and plants

Phototrophs - sources of energy for cells

- organisms that use light as an energy source

Why are Diploid cell cultures preferred? (2)

- original phenotype is lost with continuous cell cultures ex. HeLa cells no longer diploid because they've lost so many chromosomes (76-80 chromosomes)

2 physical effects of water on cells

- osmotic pressure - hydrostatic pressure

Skin (3)

- outer Epidermis; inner Dermis - physical structure and chemical components lend to an effective defense - 2 basic characteristics: barriers (tightly joined cells) and clearance (outermost cells slough off)

Cortex of Lymph Node (3)

- outer portion - consists of a tough capsule surrounding primary follicles --> B cell CLONES replicate here

Oxygen Requirements for Cells

- oxygen is essential for Obligate Aerobes - oxygen is deadly for Obligate Anaerobes Why? - The toxic forms of oxygen are those that are highly reactive and excellent oxidizing agents. Resulting oxidation causes irreparable damage to cells.

Parasitism (5)

- parasite derives benefit from its host while harming it - some hosts are only slightly harmed; some hosts are killed - parasites that allow their hosts to survive are more likely to spread --> hosts that tolerate a parasite are more likely to reproduce --> results in coevolution toward commensalism or mutualism

Resident Microbiota

- part of the normal microbiota throughout life - found on skin and mucous membranes of digestive tract, upper resp. tract, distal urethra, and vagina - mostly Commensal --> res. microbiota benefit; humans benefit but aren't harmed

Convalescence - 5th Stage of Infectious Disease

- patient recovers from the illness

gamma rays - ionizing radiation (3)

- penetrate well but require hours to kill microbes - FDA approves use in meats, spices, fresh fruits and vegetables - ex. kills microbes, kills larvae/eggs, kills cells of crops to prevent spoilage and overripening

Review - what is PBP?

- penicillin-binding-protein catalyzes the tetrapeptide crossbridges between NAM molecules

Sweat Glands (4)

- perspiration contains salt, antimicrobial peptides, and lysozyme --> Salt draws water osmotically from pathogens, inhibiting their growth and killing them --> Dermcidin --> Lysozyme destroys cell wall of bacteria

Culturing Viruses in Bacteria - Mature Organism Media (4)

- phages can be grown in bacteria in liquid cultures or on agar plates - phage-infected bacteria lyse and release new phages that infect nearby bacteria - results in a bacterial lawn interrupted by clear Plaques (areas of lysed bacteria) - each Plaque is the work of a single phase, spreading and multiplying

Macrophages - mature monocytes (7)

- phagocytic cells of the second line of defense - devour foreign objects, including bacteria, fungi, spores, and dust as well as dead body cells - often named for their location in the body, because they specialize for each body tissue - Ex. Wandering macrophages leave the blood via diapedesis and perform their scavenger function while traveling throughout the body in intracellular spaces - Ex. alveolar macrophages of the lungs - Ex. microglia of the central nervous system - Fixed macrophages generally phagocytize within specific organs

10 Major Categories of Antimicrobial Chemicals Used as Antiseptics and Disinfectants

- phenols - alcohols - halogens - oxidizing agents - surfactants - heavy metals - aldehydes - gaseous agents - enzymes - antimicrobials

Other chemical requirements for cells - from professor notes

- phosphorus (phospholipid membranes, DNA, RNA, ATP and some proteins) - sulfur (sulfur-containing amino acids critical to tertiary structure of proteins; vitamins like thiamine (B1) and Biotin) - Trace elements (only small amounts required for microbial metabolism) - Growth Factors (necessary organic chemicals that can't be synthesized by certain organisms (amino acids, vitamins, purines, cholesterol, NADH, heme, pyrimidines)

Phenotype (3)

- physical characteristics and functional traits of an organism - includes structures, morphology, and metabolism ex. shape of cell, presence/location of flagella, membrane receptors are all phenotypic traits

Platelets (2)

- pieces of Megakaryocytes that have split into small portions of cytoplasm surrounded by cytoplasmic membranes - Involved in blood clotting

Staphylococci (2)

- planes of cell division are random - clusters form

Saturation Point (2)

- point at which all enzymes are saturated; all possible active sites are full - the addition of more substrate will NOT increase the rate of enzymatic activity

Why are the lungs of smokers not properly cleared of mucus? (3)

- poisons and tars in tobacco smoke damage cilia - smokers may develop severe coughs as their respiratory tracts attempt to expel excess mucus - may succumb to many respiratory pathogens because they can't effectively clear out pathogens

Hyperthermophiles (4)

- require temps above 80 C - some can live in boiling water (over 100 C) - don't cause disease because they "freeze" at body temp - stabilize their proteins with extra Hydrogen and covalent bonds between amino acids

amphotericin B (5) - disruption of cyto membranes

- polyene; antifungal drug - attach to ergosteral in fungal membranes - humans somewhat susceptible because cholesterol is similar to ergosterol BUT amph-B attaches to ergosterol better! - bacteria LACK sterols and aren't susceptible - administered intravenously

Differential media - 6 types of culture media (3)

- presence of visible changes in the medium or differences in the appearance of colonies help microbiologists differentiate among the kinds of bacteria growing ex. blood agar that changes color in response to blood digestion ex. carb utilization tubes

Type I (α and β) Interferons (7)

- present early in viral infections --> virally infected monocytes, macrophages, and some lymphocytes secrete small amounts of alpha interferon (IFN-α) --> virally infected fibroblasts secrete small amounts of beta interferon (IFN-β) - act on the cells that secrete them; trigger protection for nearby uninfected cells - bind to IFN receptors on the cyto-membrane --> triggers production of AVPs - IFNs activate NK and other lymphocytes

Autoclaving - Moist Heat Methods (3)

- pressure applied to boiling water prevents steam from escaping, provides true sterilization. Why? - Boiling temperature increases as pressure increases - Autoclave conditions: 121ºC, 15 psi, 15 min

Osmotic Pressure (6)

- pressure exerted on a semipermeable membrane by a solution containing solutes that cannot freely cross membrane - the amount of hydrostatic pressure required to stop osmosis = osmotic pressure —> the pressure of a solution against a semi-p membrane to prevent water from flowing inward) - Hypotonic solutions have a lower solute concentration (hypotonic = low osmotic pressure) - Hypertonic solutions have a higher solute concentration (hypertonic = high osmotic pressure) - restricts organisms to certain environments (obligate and faculative halophiles)

What do Antiphagocytic factors do? (from chapter video) (3)

- prevent engulfment (bacterial capsules) (M protein) - prevent digestion (chems that prevent fusion of lysosome w/ phagosome) - kill phagocytes (leukocidin is a cytotoxin that kills phagocytes)

Aspirin and ibuprofen are antiprostaglandins. How do they work? (2)

- preventing synthesis of prostaglandins, which drive fever and pain

self-tolerance (2)

- prevents the body from mounting an immune response against itself - immune cells that treat autoantigens as if they were foreign are normally eliminated during the development of the immune system

Antigen-Presenting Cells (APCs) (4)

- process antigens and activate cells of the immune system - includes: B lymphocytes, macrophages, dendritic cells - "Professional" antigen-presenting cells regularly present antigens --> specialize in presenting antigen to T cells

Positive Selection - methods to recognize mutants (2)

- process by which mutants are selected by eliminating wild-type phenotypes - ex. lab wants to isolate penicillin-resistant mutants. They spread penicillin-sensitive cells, the mutants, and penicillin on a growth plate. only the peni-resistant mutants survive.

Nitrogen Fixation (3)

- process of converting nitrogen gas (N2) into ammonia (NH3) - only certain bacteria are capable of this; ex. cyanobacteria - essential for life on Earth because nitrogen fixers provide nitrogen in a form usable by other organisms

cathode ray machines - ionizing radiation (3)

- produce Electron beams - fast, high energy; but can't sterilize thick objects or coats of organic matter - ex. meats, spices, plastic ware, dental/medical supplies

Polymyxin - disruption of BACTERIAL cyto-membrane (4)

- produced by Bacillus polymyxa - effective against Gram-negative bacteria, particularly Pseudomonas - toxic to human kidneys --> it's reserved for use against external pathogens that are resistant to other antibacterial drugs

Antiviral Proteins (AVPs) (6)

- produced by IFNs binding to viral-infected cell cyto-membranes - remain inactive within these cells until AVPs encounter viral nucleic acids (helix RNA) (common in viruses, absent in Euk) - oligoadenylate synthetase destroys RNA - protein kinase R inhibits protein synthesis by ribosomes - AVPs destroy the protein production system of the cell, preventing viruses from being replicated (cell metabolism IS affected) - antiviral state lasts 3-4 days

Type II (Gamma) Interferons (4)

- produced by active T lymphocytes and NK lymphocytes - appear later (bc T lymph are activated in adaptive response days after infection start) - AKA "macrophage activation factor" - regulates the immune system by activating phagocytic activity

Endogenous Antigens (4)

- produced by intracellular microbes and are typically incorporated into a host cell's cytoplasmic membrane - Protozoa, fungi, bacteria, and viruses that reproduce inside a body's cells - immune system cannot assess the internal health of the body's cells --> responds to endogenous antigens only if the body's cells incorporate such antigens into their cytoplasmic membranes, leading to their external display

Vertical Gene Transfer (2)

- prok. and euk. replicate their genomes and supply copies to their offspring - "the passing of genes to the next generation"

Prokaryotic Plasmids (7)

- prokaryotic cells contain 1+ plasmids - small, circular molecule of DNA that replicates independently of the chromosome - each carries genes for its own replication - often carries genes from one or more nonessential functions (can confer survival advantages) (resistance to antimicrobial drugs) - most plasmid-carried genes aren't essential for metabolism, growth, or cellular reproduction - usually circular - 1-20% of the size of a prokarytic chromosome

Species Resistance

- property that protects a type of organism from infection by pathogens of other, very different organisms

Flagellin (4)

- protein that makes up flagella - form helical chains around a hollow core - flagellum lengthens by growing at the tip as flagellin is deposited in a clockwise helix at the tip of the filament - growth is inhibited in dry habitats

Integral Proteins

- proteins that either penetrate the entire phospholipid bilayer of the cytoplasmic membrane or penetrate halfway

possible cocci arrangements (6)

- single - diplococci - streptococci - tetrads - sarcinae - staphylococci

Chemiosmosis (5)

- protons flow down electrochem. gradient through ATP synthases that phosphorylate ADP to ATP - use of electrochemical gradients form ATP - creates proton gradient from energy released in ETC - called oxidative phosphorylation because proton gradient created by oxidation of components of ETC - 34 molecules of ATP formed here

Capsid Morphology - differences in viruses (6)

- provide protection for viral nucleic acid - means of attachment to host's cells for naked (nonenveloped) viruses - composed of proteinaceous subunits called Capsomeres --> made of a single or multiple types of proteins - may contain proteins/enzymes required for viral function --> replication or suppression of cell functions

Cellular Respiration (3)

- pyruvic acid from glycolysis is completely oxidized to produce ATP by a series of redox reactions - 3 stages —> Synthesis of acetyl-CoA; Krebs cycle; redox reactions followed by chemiosmosis

Transposition

- rare mutation in which a genetic segment is transferred to a new position through the action of a DNA segment called a transposon

Horizontal (Lateral) Gene Transfer (5)

- rare! occurs in <1% of prok. pop. - many prokaryotes can acquire genes from microbes of the same generation - donor cell contributes part of their genome to a recipient cell - recipient becomes 'recombinant cell' - enzymes degrade remaining unincorporated donor DNA

Stationary Phase - 3/4 phases of microbial growth (3)

- rate of reproduction decreases - number of dying cells equals number of cell produced - populations at this phase are stress tolerant

Therapeutic Index (TI) (3)

- ratio of the largest dose of a drug that is not toxic to the drug's smallest effective dose - helps estimate the safety of drugs - the higher the TI, the safer the drug

NOD Proteins (6)

- receptors for microbial molecules like PAMPs - in CYTOPLASM (not membrane like TLRs) - trigger inflammation, apoptosis, and other innate immune responses against bacterial pathogens - Mutations in NOD genes are associated with several inflammatory bowel diseases (Crohn's) - bind to Gram- walls - bind to RNA viruses (AIDS, Hep C, mononucleosis)

Proteins of cell membranes may acts as: (5)

- recognition proteins - enzymes - receptors - carriers - channels

Primary Lymphoid Organs (2)

- red bone marrow - thymus

Signs/Symptoms of Inflammation (4)

- redness in light skin (rubor) - localized heat (calor) - edema (swelling) - pain (dolor)

3 Ways to Preserve Cultures

- refrigeration - deep-freezing - lyophilization

Review - What physical methods of microbial control inhibits metabolism?

- refrigeration/freezing - dessication (drying) - osmotic pressure

What can proteins do? (3)

- regulate cell metabolism - function as enzymes in most metabolic reactions - form structural components in membranes/cytoplasm

operator - part of operon (2)

- regulatory element in an operon where repressor protein binds to stop transcription - controls movement of RNA polymerase

Recombination (2)

- relatively long stretches of DNA move among chromosomes, plasmids, and viruses, introducing frameshift mutations - can cause spontaneous mutations

How is a nucleotide both a building block and an energy source? (2)

- removal of a pyrophosphate (diphosphate) from a nucleotide during DNA synthesis releases energy - this energy bonds the nucleotide to the existing DNA strand during synthesis

Sanitation

- removal of pathogens from objects to meet public health standards

Lyophilization - Physical Methods of Microbial Control (5)

- removal of water from a frozen substance (via liquid nitrogen or dry ice) by vacuum pressure - long-term preservation of microbial cultures - not all cells survive but enough are viable - prevents formation of damaging ice crystals - (-196 C) for a few minutes while drying

Lyophilization - 3 ways to preserve cultures (3)

- removing water from a frozen culture using an intense vacuum - ice sublimates (directly becomes gas) and is removed from cells without permanently damaging cellular structures and chemicals - stores for decades

Error-Prone Repair - method of DNA Repair (5)

- repair of double-strand damage - "SOS response" in E. Coli - prokaryotic - DNA polymerases (IV and V) are induced to replicate damaged DNA with little regard to base sequence - results in many new and potentially fatal mutations

Lytic Replication of Viruses (2)

- replication that usually results in the death and lysis of the host cell - occurs in both Bacteriophages and Animal Viruses

tryptophan (trp) operon (5)

- repressible polycistronic operon - consists of: promoter, operator, 5 genes that code for enzymes that synthesize Tryptophan - regulatory genes is constantly made, producing an inactive repressor (lac repressor is usually active btw) - thus, trp operon is usually active - cell transcribes mRNA, translates the enzymes for tryptophan synthesis, and synthesizes tryptophan

What happens if tryptophan is absent in the cell? (2)

- repressor is inactive - the structural genes are transcribed and translated, and the five enzymes needed in the synthesis of tryptophan are produced.

Acidophile (4)

- require a highly acidic pH - many fungi and some bacteria - obligate acidophiles require acidity and die in neutral pH - acid-tolerant microbes merely survive, not thrive, in acid

Neutrophiles (2)

- require a neutral pH (6.5 - 7.5) - most bacteria and protozoa (the human body is in the neutral pH range)

Obligate Halophiles (3)

- require high osmotic pressure (hypertonic environment) - osmotic pressure restricts organisms to certain environments - may grow in up to 30% salt; will lyse in freshwater

Thermophiles (3)

- require temps above 45 C (compost piles and hot springs) - don't cause disease because they "freeze" at body temp - stabilize their proteins with extra Hydrogen and covalent bonds between amino acids

Mesophiles (3)

- require temps from 20-40 C; can survive lower/higher - human pathogens are mesophiles (body temp is 37 C) thermoduric organisms are mesophiles that can survive brief periods at higher temps (inadequate heating during pasteurization or canning can spoil food)

Psychrophiles (5)

- requires below 20 C - grows best at 15 C - can grow below 0 C - psychrophilic algae, fungi, archaea, and bacteria live in snowfields, ice, and cold water - don't cause disease in humans because they can't survive our body temperature (37 C)

Normal Microbiome Contains 2 Types of Organisms

- resident microbiota - transient microbiota

Naturally Acquired Active Immunity (4)

- resulting from infection - contact with pathogens - body responds to exposure to pathogens and environmental antigens by mounting specific immune responses - body is naturally and actively engaged in its own protection

* Lysogenic Conversion (3)

- results when phages carry genes that alter phenotype of a bacterium - can change a harmless cell into a pathogen - Ex. Phage CTXφ infects Vibrio cholerae. Cholera toxin is within genome of phage.

Archaea ribosome 70S (3)

- ribosomal proteins more similar to eukaryotic ribosomal proteins - they use different metabolic enzymes than bacteria to make RNA - they use a genetic code more similar to the code used by eukaryotes

2 types of non-membranous organelles found in bacterial cytosol (3)

- ribosomes (prokaryotic ribosomes are 70S; eukaryotic ribosomes are 80S) — many antibacterial drugs act on 70S ribosomes and don't affect 80S; drugs are able to stop protein synthesis in bacteria without stopping protein synthesis of the patient - cytoskeleton

Why are frameshift mutations harmful? (3)

- ribosomes translate mRNA into proteins by reading the 2-nucleotide codons - the insertion/removal of one or two nucleotides results in a shift in the reading frame of the codons - nearly every codon and AA is changed subsequent to the frameshift mutation

Cancers (3)

- rob normal cells of space and nutrients and cause pain - in some cancers, malignant cells derange function of affected tissue - body eventually can no longer withstand the loss of normal function and dies

Inoculum (4)

- sample introduced into medium to cultivate or culture microorganisms - environmental specimens - clinical specimens (from patients) - stored specimens (obtained previously)

Genetic Methods - Measuring Microbial Reproduction (6)

- scientists isolate DNA sequences of un-culturable prokaryotes - Highly specific and much more selective, unlike culture techniques - Faster, no culture required - Based on DNA and are therefore generic. Avoids having to use different medias for each microbe type ex. Chlamydia test can have 2 hour results (compared to 3-5 day culture) ex. HIV viral load test determines if treatment is working

Large Algae (3)

- seaweeds & kelps; common in oceans - gelatinous chems from their cell walls are used as thickeners & emulsifiers - Agar is used to solidify laboratory media

MALT (6)

- secondary lymph organ - contains most of the body's lymphocytes - lack tough outer capsule - lymphoid tissue associated with the mucous membranes of the appendix - lymphoid tissue of the respiratory tract, vagina, urinary bladder, and mammary glands - discrete bits of lymphoid tissue called Peyer's patches in the wall of the small intestine

Tonsils (4)

- secondary lymph organ - lack tough outer capsule - similar to lymph nodes but have no afferent/efferent vessels - sample microbes that enter the mouth or nose

Spleen (8)

- secondary lymph organ - similar in structure and function to lymph nodes - have a tough outer capsule like the nodes - filters BLOOD, not lymph - removes bacteria, viruses, toxins, and other foreign matter - cleanses the blood of old and damaged blood cells - stores blood platelets - stores blood components, such as iron

Helper T Cells

- secrete cytokines to activate other cells of the immune system

Sebaceous (Oil) Glands (3)

- secrete sebum --> Helps keep skin pliable and less likely to break or tear --> Contains fatty acids that lowers skin to about pH 5, which is inhibitory to many bacteria

Exotoxins (5)

- secreted by a living organism (ex. bacteria) that harms neighboring cells - Ex. Cytotoxin released by bacteria that kills the host's cells - Neurotoxin (interfere w/ nerve cells) - Enterotoxins (interfere w/ cells of gastrointestinal tract) - Cytotoxins (disrupt host cells and destroy tissue)

Clonal Deletion of B Cells (2)

- self-reactive B cells may become inactive or change their BCR rather than undergo apoptosis - removed from the active B cell repertoire

Function of the Cytoplasmic Membrane (3)

- separates the cell contents and the outside environment - controls passage of substances in/out of the cell; it is selectively permeable - harvests light energy in photosynthetic bacteria producing ATP

Prokaryotic tRNA (4)

- sequence of about 75 ribonucleotides that curves back on itself to form 3 main hairpin loops held in place by Hydrogen bonds between bases - bottom loop has an anticodon (tRNA section complementary to a codon on mRNA) - bottom loop has an acceptor stem on the 3 ' end (designed to carry one particular AA; varies with the tRNA) - aminoacyl tRNA synthetases "charge" a specific tRNA molecule, attaching the appropriate amino acid to the acceptor stem

8 Characteristics of Bacterial Colonies (each have listings)

- shape (5) - margin (5) - elevation (5) - size (punctiform, small, moderate, or large) - texture (smooth or rough) - appearance (glistening/shiny or dull) - pigmentation (non- or pigmented) - optical property (opaque, translucent, or transparent)

Archaeal Translation (2)

- similar to that of eukaryotes - BUT they lack endoplasmic reticulums

Monobactams

- simplest synthetic beta-lactams - effective ONLY against aerobic Gram-negatives

Insertion Sequences (2)

- simplest transposons - consist of only 2 inverted repeats & a gene that encodes the enzyme transposase

Lymph Nodes (4)

- sites to facilitate interactions among immune cells and between immune cells and material arriving at lymph nodes from throughout the body - afferent vessels inbound - efferent vessels outbound - concentrated in the cervical (neck), inguinal (groin), axillary (armpit), and abdominal regions

How does the "chill" associated with fever come about? (2)

- skin BVs constrict as the fever progresses which undoes the vasodilation of inflammation - constricted skin vessels carry less blood making the skin feel cold

Physical Barriers - 1st Line of Defense (3)

- skin and mucous membranes - made up of structures, chemicals, and processes that work together to prevent pathogens from entering the body in the first place - When these barriers are pierced, broken, or otherwise damaged, they become portals of entry for pathogens

Archaeal Flagella (8)

- slower than bacteria - half as thick as bacteria (10-14 nm) - not hollow like bacteria - grow at base of filament (instead of tip like bacteria) - share common AA sequences across species (v different sequences than bacteria) - sugar molecules attached to filaments of many archaea (rare in bacteria) - powered by stored ATP (instead of Hydrogen ions of bacteria) - bundle both when turning ccw or cw

Primary Response (4)

- small amounts of antibodies are produced - may take days before sufficient antibodies are made to completely eliminate the toxoid from the body - basically ends when the plasma cells die - memory B and T cells created

Seawater (3)

- solution containing about 3.5% solutes (hypertonic to most cells) - a cell placed in seawater will lose water - crenation can occur (shriveling of the cytoplasm)

* Beta-lactamases (2)

- some bacteria make these enzymes to degrade beta-lactams - most Gram-negative bacteria

What is another way that some bacteria can get iron? (4)

- some can secrete the protein hemolysin --> punches holes in the cytoplasmic membranes of red blood cells, releasing iron-containing hemoglobin --> bacterial proteins then bind hemoglobin to the bacterial membrane and strip it of its iron - Ex. Neisseria meningitidis, a pathogen that causes often fatal meningitis, produces receptors for transferrin and plucks iron from the bloodstream as it flows by.

* Do viral capsids form around a genome? (3)

- some do - for others, enzymes pump the genome into the assembled capsid under high pressure (x5 pressure of a paintball gun) - sometimes a capsid forms around residual host DNA --> virion formed transfers HOST DNA instead of viral DNA (TRANSDUCTION!!!)

How are scientists trying to stop biofilms? (3)

- some drugs can block microbial cell receptors (for quorum sensing), disrupting communication and inhibiting biofilm formation - enzymes that degrade the extracellular matrix of biofilms to enhance penetration of antimicrobial drugs - artificially amplifying quorum sensing while bacteria are still few in number; bacteria reveal themselves early and can be eliminated

Disruption of Cytoplasmic Membranes - 3/6 Mechanisms of Microbial Drug Action (2)

- some drugs form a channel through cytoplasmic membrane and damage its integrity - ex. Gramicidin (short polypeptide); Polyenes

The Development of Resistance in Populations (4)

- some pathogens are naturally resistant - Resistance by bacteria acquired in two ways: - New mutations of chromosomal genes - Acquisition of R-plasmids via transformation, transduction, and conjugation

How do phagocytes destroy invading pathogens but leave the body's healthy cells unharmed? (2)

- some phagocytes have receptors for microbial surface components that are LACKING on the body's cells (body cells can't bind to these!) (ex. cell wall components or flagellar proteins) - Opsonins like blood proteins or antibodies provide signals to the phagocyte

Why is fermentation important? (7)

- sometimes cells can't completely oxidize glucose via cellular respiration - cells require a constance source of NAD+ to live —> Glycolysis and Kreb's consume NAD+; can't create new NAD+ - fermentation pathways provide cells with a NAD+ source —> allows recycling of NADH to NAD+ —> partially oxidizes sugars/metabolites to release energy —> uses organic molecules within cell as final electron acceptor

What does miRISC do? (3)

- sometimes cuts mRNA, making it useless - sometimes remains bound to mRNA, hiding it from ribosomes - thus, miRNAs (associated with RISC) regulate gene expression by blocking translation

What 3 things do all cells need for metabolism?

- source of carbon - source of energy - source of electrons or Hydrogen atoms

Periplasmic Space (3)

- space between outer membrane and cytoplasmic membrane of Gram-negative bacteria - contains the peptidoglycan and periplasm (gel between membranes) - Periplasm contains water, nutrients, and substances such as digestive enzymes, peptidoglycan assembly enzymes and specific transport proteins

Operons (3)

- special arrangements of Prok. genes involved in gene regulation - consists of a promoter, series of genes that code for enzymes/structures, and some are controlled by an operator - can be polycistronic (may code for more than one polypeptide)

reducing media (4)

- special culturing medium containing compounds that combine with free oxygen and remove it from the medium ex. an anaerobic culture system can consist of an airtight jar (sealed w/ a clamp) with the petri plates, methylene blue, palladium pellets and an envelope w/ chemicals that release CO2 and H2 — the palladium pellets catalyze reactions removing oxygen — methylene blue turns clear in the absence of oxygen and will indicate the anaerobic environment

Pili (5)

- special type of fimbriae - AKA "conjugation pilus" - usually longer than other fimbriae but shorter than flagella - sparse when present - capable of "conjugation"

Mast Cells

- specialized cells located in connective tissue that release Histamine when they are exposed to Complement

Adhesion Factors - Adhesion in Infection (2)

- specialized structures or attachment molecules - Capsule, slime layer, fimbriae

5 Distinct Attributes of Adaptive Immunity

- specificity - inducibility - clonality - unresponsiveness to self - memory

mucous membrane of the trachea

- stem cells produce both goblet cells --> secrete an extremely sticky mucus that acts as a barrier, trapping bacteria and other pathogens - ciliated columnar cell cilia propel the mucus and its trapped particles and pathogens up and away from the lungs - Mucus carried into the throat is coughed up and either swallowed or expelled (BARRIER AND CLEARANCE)

Fimbriae (7)

- sticky, bristlelike, rodlike proteinaceous (composed of proteins) extensions that allow adherence to other fimbriae or environment - may be hundreds per cell - usually shorter than flagella - pathogens must be able to adhere to host for survival and to spread disease - some fimbriae carry enzymes that render soluble, toxic metal ionsinto insoluble, nontoxic forms - contribute to biofilm adhesion & can conduct electrical signals across the mass

Antibody-Epitope bond (2)

- strong, highly specific, noncovalent interaction - hydrogen bonds and other molecular attractions mediate antibody binding to epitope

What does a cell wall provide prokaryotes? (6)

- structure - shape to the cell - protection from osmotic forces - assists in attachment - assists in resisting antimicrobial drugs ex. penicillin attacks bacteria cell walls but it harmless to humans because we don't have cell walls

Nucleoside Analogs - type of chemical mutagen (4)

- structure similar to nucleosides but have different base pairing properties - can be added to replicated DNA, replacing their related base - can inhibit further replication or cause mismatching in the future ex. 5-bromouracil is a nuceloside analog of Thymine that often pairs with Guanine instead of Adenine (base sub. mutation)

Iatrogenic Infections (3)

- subset of nosocomial infections that are the direct result of a medical procedure or treatment, such as surgery - "doctor-induced" infections - direct result of modern medical procedures such as the use of catheters, invasive diagnostic procedures, and surgery

Inhibitors - enzyme reaction rate factors (6)

- substances that block enzyme activity - Competitive inhibitors bind to the active site, preventing the normal substrate from binding — > don't undergo a chem. reaction to form products —> can be permanent or reversible; overcome by an increase of substrate molecules - Noncompetitive inhibitors bind to an allosteric site —> alters shape of active site so activity is reduced or blocked

3 ways cells can phosphorylate ADP to ATP

- substrate-level phosphorylation - oxidative phosphorylation - photophosphorylation

Biosafety Level 1 (BSL-1) (3)

- suitable for handling microbes not known to cause disease in healthy humans - ex. E. Coli - minimal precautions (hand-washing, disinfecting surfaces)

Biosafety Level 2 (BSL-2) (5)

- suitable for handling moderately hazardous agents - ex. hepatitis, influenza viruses, methicillin-resistant Staphylococcus aureus (MRSA) - lab access limited while working - extreme precaution w/ sharp objects - aerosols used in safety cabinets

Arildone (3)

- synthetic antiviral - prevents removal of poliovirus capsids (uncoating) - interrupting the viral replication cycle

4 Factors that Influence Rate of Enzymatic Reactions

- temperature - pH - Enzyme and substrate concentrations - presence of activators or inhibitors

Physical Requirement for Microbial Growth (4)

- temperature - pH - osmolarity (osmotic pressure) - hydrostatic pressure

Environmental Conditions - 3 Factors Affecting Efficiency of Antimicrobial Agents

- temperature and pH - organic materials

What environmental conditions affect efficiency of chemical antimicrobial agents? (5)

- temperature/pH - concentration - freshness of chemical - length of exposure - amount of contaminating organic matter in the environment

Termination of Transcription - last step of bacterial transcription

- terminates when RNA polymerase and the transcribed RNA are released from RNA - 2 type of termination (self-termination & Rho-dependent)

the Kelsey-Sykes Capacity test (2) - Methods to Measure Efficiency of Antimicrobial Agents

- test strains of bacteria are added to disinfectants and then removed and placed in broth and turbidity of the resulting culture is measured - standard alt. assessment approved by the European Union

How is peptidoglycan formed? (3)

- tetrapeptide crossbridges (amino acids) connect adjacent NAM molecules from NAG-NAM chains; catalyzed by PBP - depending on the bacterium, the bridges are either bonded to one another (covalent bonds) or by short connecting chains of more amino acids - covers the entire surface of the cell

What happens when an antigenic epitope binds to a specific B cell via its BCR? (3)

- the B cell is activated (becomes Plasma cell) - the B cell undergoes cell division - its offspring secrete immunoglobulins which act against the same epitope that activated the B cell

Enzyme-substrate specificity (5)

- the activity of enzymes depends on the closeness of fit between the active site and the substrate —> active site - the shape of an enzyme's functional site - active site is complementary to the shape of the substrate - 'lock and key' concept — > the active site and substrate have to be of similar shape for them to bind

Genotype (3)

- the actual set of genes in its genome - at the molecular level, consists of all the series of DNA nucleotides that carry instructions for life - differs from the genome because the genome contains nucleotides that aren't part of genes (such as nucleotide sequences that link one gene to another) (genotype + extra stuff = genome)

Fibrinogen (4)

- the blood's clotting protein - delivered to infection site thanks to vasodilation and increased permeability - prevents the spread of pathogens and toxins from the area - pus forms in the walled off area (abscess) (pimples, boils, pustules)

Descriptive Epidemiology (3)

- the careful recording of data concerning a disease - location, time, ages, genders, occupation, health histories, socioeconomic groups - index case (first case) should be found

A bacterial population that has been growing for 15 generations began as a single cell. How many cells are present now?

32,768 (# of cells x 2^generation #) (1 x 2^15) = 32,768

How are humans a dead-end host for zoonotic pathogens? (4)

- the circumstances under which zoonoses are transmitted favor movement from animals to humans but not in the opposite direction - animals don't eat humans much these days - animals aren't so exposed to human waste - most likely method of transfer would be bloodsucking arthropods

Opsonization (3)

- the coating of pathogens by proteins called Opsonins, making them more vulnerable to phagocytes - Opsonins increase the number and kinds of binding sites on a microbe's surface - complement proteins or antibodies help prepare pathogens for easier phagocytizing

Holoenzyme (2)

- the combination of an apoenzyme and it cofactor(s) - a complete and active enzyme

Microbial Antagonism (4)

- the competition between normal microbes and pathogens for nutrients and space - reinforces the body's defense by limiting the ability of pathogens to colonize the skin and mucous membranes - No room or nutrients for pathogens means they're unable to colonize - Any reduction in microbial antagonism may result in an infection.

Probiotics (2)

- the concept that it is sometimes better to introduce beneficial microbes to resolve or prevent a disease rather than kill pathogens after they attack - mitigates the development of antibiotic resistance

How is the epidermis replaced? (4)

- the deepest cells continually divide, pushing their daughter cells toward the surface - the rising daughter cells flatten and die - they are eventually shed as flakes - Microorganisms that attach to the skin's surface are sloughed off with the flakes of dead cells

Wavelength of electromagnetic radiation

- the distance between two crests of a wave Short (more energy): - electrons - very short gamma rays - X-rays - UV - visible light Long (less energy): - radio waves

What happens to a virus if its protein/phospholipid envelope is damaged? (2)

- the envelope is a membrane responsible for the attachment of the virus to its target cell - damage to the envelope prevents viral replication

Genetic Recombination

- the exchange of nucleotide sequences between two DNA molecules - often involves homologous sequences

Innate Immunity (4)

- the first 2 lines of defense - "natural" or "native" immunity; present at birth - always active, NONspecific, rapid - works against a wide variety of pathogens, including parasitic worms, protozoa, fungi, bacteria, and viruses

Serum

- the fluid remaining when clotting factors are removed (as when blood clots)

Considering microbial antagonism of the microbiome, why is using antimicrobial soaps bad for you?

- the human microbiome plays many roles in protecting us from infection, from inhibiting invading pathogens and training the immune system, to strengthening immune responses

The "crisis" of a fever

- the infection comes under control, fewer active phagocytes means less pyrogens - thermostat is reset to 37 C - sweating - metabolic rate lowers - skin BVs dilate **These are signs that the infection has been overcome and body temp is returning to normal.

Why are many cheeses acidic? (2)

- the lactic acid produced by fermenting bacteria and fungi - the pH acts as a preservative by preventing further microbial growth

Bacterial cells package what in their chromosomes? (3)

- the main portion of their DNA - associated molecules of protein - RNA

Contamination (2)

- the mere presence of microbes in or on the body - Microbes may be removed, become part of resident microbiota or transient microbiota, or cause infection

Complexity of Antigens

- the more complex, the more Epitopes - Ex. glycoproteins and phospholipids

Nucleosomes (2)

- the negatively charged Eukaryotic DNA wraps around positively charged globular histone proteins - forms 10-nm-diameter beads (nucleosomes)

Microbial Death

- the permanent loss of reproductive ability under ideal environmental conditions

Methods to Measure Efficiency of Antimicrobial Agents

- the phenol coefficient - the use-dilution test - the Kelsey-Sykes capacity test - the in-use test

Arrangement of Prokaryotes Results From 2 Aspects During Binary Fission (2)

- the planes in which cells divide - whether or not daughter cells remain attached to each other

Translation cont.

- the process whereby ribosomes use the genetic information of nucleotide sequences to synthesize polypeptides composed of specific amino acid sequences Molecules of tRNA (delivery trucks) deliver preformed amino acids (auto parts) to a ribosome (car factory), which can manufacture an infinite variety of polypeptides (car models) by assembling amino acids in the correct order according to the instructions from DNA (corporate headquarters) delivered via mRNA (special courier middle man).

Therapeutic Window

- the range of concentrations of the drug that are effective without being excessively toxic

Degerming (4)

- the removal of microbes from a surface by scrubbing - soap/alcohol are common but the scrubbing action is more important ex. hand-washing ex. nurse preparing skin for injection

Lymphocyte (4)

- the smallest leukocytes - have nuclei that nearly fill the cells - Most are involved in adaptive immunity - natural killer (NK) lymphocytes function in innate defense

Genetics (2)

- the study of inheritance and inheritable traits as expressed in an organism's genetic material - geneticists study the physical structure and function of genetic material, mutations, and the transfer of genetic material among organisms

group translocation (active transport) (4)

- the substance transported across the membrane is chemically changed during transport - the membrane is impermeable to the altered substance, trapping it within the cell - often used by bacteria; very efficient ex. accumulation of glucose inside a bacterial cell

Aerobic respiration supplies how much ATP?

38 molecules in prokaryotes 36 in eukaryotes

Experimental Epidemiology (3)

- the testing of hypotheses resulting from analytical epidemiology concerning the cause of a disease - Ex. application of Koch's postulates to determine etiology - involves studies to test a hypothesis resulting from an analytical study, such as the efficacy of a preventive measure or certain treatment

Pasteurization

- the use of heat to kill pathogens and reduce the number of spoilage microorganisms in food and beverages

Direct Penetration - Entry Method of Animal Viruses (2)

- the viral capsid attaches and sinks into the cytoplasmic membrane, creates pore - genome enters through pore, leaving empty capsid outside ex. Poliovirus

Membrane Fusion - Entry Method of Animal Viruses (3)

- the viral envelope and the host's cytoplasmic membrane fuse - capsid released into cell's cytoplasm - envelope glycoproteins are left in cell membrane

How are the cytokines named? (3)

- their cells of origin - their function - and/or the order in which they were discovered

Why are there few antiviral drugs? (3)

- there ARE major differences between eukaryotes and viruses BUT - viruses utilize their host cells' enzymes and ribosomes to metabolize and replicate - therefore, drugs that are effective against viral replication are likely toxic to the host as well

How do antimicrobial agents work?

- they alter cell walls and membranes, damaging the integrity of the cell - damage nucleic acids, therefore proteins

How do these chemicals make venules more permeable? (4)

- they cause cells lining the vessels to contract and pull apart, leaving gaps in the walls through which phagocytes can move into the damaged tissue and fight invaders - Increased permeability also allows delivery of more bloodborne antimicrobial chemicals to the site - fluid leaking from these gaps caused edema --> puts pressure on nerve endings, producing much of the pain of inflammation

Given that prions lack RNA or DNA genes, how can they replicate themselves?

- they cause normal cellular proteins of the same type to misfold into the infectious form of prions - Prion PrP

How do NK cells kill? (2)

- they destroy target cells with proteins called perforin and granzyme - Perforin molecules form into a tubular structure in the target cell's membrane, forming a channel through which granzyme enters the cell and triggers apoptosis

Review - How do NK cell kill? (2)

- they destroy target cells with proteins called perforin and granzyme - Perforin molecules form into a tubular structure in the target cell's membrane, forming a channel through which granzyme enters the cell and triggers apoptosis

What could happen when microbes obtain nutrients by living in/on another organism? (2)

- they may cause disease - may interfere with their hosts' metabolism and nutrition

How do some bacteria like Staphylococcus aureus respond to an iron shortage? (3)

- they secrete their own iron-binding compounds called siderophores - siderophores have a greater affinity for iron than does transferrin or other proteins --> bacteria that produce siderophores can in effect steal iron from the body

Why aren't X-rays used for microbial control? (2)

- they travel farthest through matter but don't have the high energy of gamma rays - the time it would take comparatively is not practical

The first virus isolated was from a tobacco plant. Are viruses of plants well understood? (3)

- they're less known than bacterial/animal viruses - they're introduced by cell wall abrasions or by plant parasites (nematodes or aphids) - after entry, plant viruses follow animal virus replication cycle

Gram-positive bacterial cell walls (4)

- thick layer of peptidoglycan stabilized by teichoic acids - teichoic acids have a negative electrical charge; gives bacterial surface a negative charge and affects ion flow - some teichoic acids protrude into cytoplasmic membrane and covalently link to lipids, forming "Lipoteichoic Acids" - stains PURPLE with Gram-stain

Membrane Filters (2)

- thin circles of nitrocellulose or plastic containing specific pore sizes, some small enough to trap viruses - can be used to estimate the number of microbes in a fluid by counting the number deposited on the filter

Gram-negative bacterial cell walls (5)

- thin layer of peptidoglycan - has an outer membrane - porins (integral proteins) form channels though both leaflets allowing passage to midsized molecules (like Glucose) across outer membrane - space between outer and cytoplasmic membrane is the Periplasmic Space - appears PINK after Gram-stain

Epithelial Cells of Mucous Membranes (6)

- tightly packed cells form a THIN layer --> in some areas it's only a single cell thick - surface cells are alive! (unlike skin) - Continual shedding of cells carries away microorganisms - diffuse nutrients and oxygen (digestive, respiratory, and female repro systems) - eliminate wastes (urinary, respiratory, and female repro systems)

Incubation Period - 1st Stage of Infectious Disease

- time between infection and occurrence of the first symptoms or signs of disease

A disease must infect thousands or millions to be considered an epidemic. T/F (3)

- time period and # of cases isn't specified to count as an epidemic - the important fact is that there are more cases than expected, based on historical statistics - Ex. the number of cases observed did not exceed the number expected

Generation Time (3)

- time required for a bacterial cell to grow and divide - dependent on chemical and physical conditions - most bacteria require 1-3 hours

Transcription and Translation Further Explained (3)

- to a ribosome, DNA is like a foreign language written in a foreign alphabet - a cell must transcribe the "foreign alphabet" of DNA nucleotides (genes) into the more "familiar alphabet" of RNA nucleotides (mRNA) - cel must translate the message into "words" (amino acids) that can make up the "message" (polypeptide)

Functions of Eukaryotic RNA Processing Before Translation (3)

- to aid in export of RNA from the nucleus - stabilize mRNA in the cytoplasm - aid in translation

Faculative Halophiles (3)

- tolerate high osmotic pressure - can tolerate up to 20% salt (allows it to colonize our skin!) ex. Staphylococcus aureus causes skin/mucous membrane diseases (pimples, sties, boils, lethal scalded skin syndrome and toxic shock)

Mupirocin (4)

- topical drug that selectively binds to isoleucyl- tRNA synthetase (enzyme that loads isoleucine to tRNA in Gram-positive bacteria, particularly Staphylococcus and Streptococcus) - drug is selectively toxic because it does not bind to any eukaryotic tRNA molecules - with this drug, Gram-positive cells cannot load isoleucine, so protein synthesis cannot proceed past isoleucine codons - (WHO) lists mupirocin as an essential medicine for bacterial skin infections

Toxemia (2)

- toxins in the bloodstream - often carries toxins beyond the site of infection

* Generalized Transduction (2)

- transducing phage carries a random DNA segment from a donor host to a recipient host cell - not limited to a particular DNA sequence

How is iron transported in humans? Why? (3)

- transferrin, a transport protein, carries iron via plasma to cells - transferrin-iron complexes binding to their receptors triggers the cell to take up Iron via endocytosis - Why is it needed? Iron is relatively insoluble

What are scientists trying to do with TLRs? (2)

- trying to stimulate TLRs so as to enhance a body's immune response to pathogens and immunizations - methods to inhibit TLRs may provide us with ways to counter inflammatory disorders and hyperimmune responses

What happens if tryptophan is present in the cell? (4)

- tryptophan acts as a co-repressor - binds to the repressor, activates it - repressor binds to operator, halting movement of RNA polymerase and transcription - tryptophan stops its own synthesis

Agranulocytes (3)

- type of leukocyte having a uniform cytoplasm lacking large granules - granules ARE visible with an electron microscope - 2 types (monocyte, lymphocyte)

Frameshift Mutations (5)

- type of point mutation (from professor notes) - when nucleotides are inserted/removed from the DNA sequence - Insertion and Deletion - typically result in drastic Missense & Nonsense mutations - usually lead to nonfunctional proteins --> UNLESS the mutation is very close to the end of a gene

Repressible Operons (3)

- typically active until "turned off" by repressors - transcribed continually until deactivated by repressors - often produce proteins involved in anabolic pathways

Molds (3)

- typically multicellular - grow as long filaments that intertwine to make up the body of the mold - reproduce with sexual & asexual spores

How are mutations in multicellular organisms passed on?

- typically passed on ONLY if a mutation occurs in gametes (sex cells) or gamete-producing cells

Animal Cell Division (4)

- under strict genetic control - Genes dictate that some cells can no longer divide - Cells that can divide are prevented from unlimited division - Genes for cell division "turned off" or genes inhibiting division "turned on"

Yeasts (4)

- unicellular - typically oval to round - reproduce asexually by "budding" - some also produce sexual spores

Lipopolysaccharide (LPS) (3)

- union of lipid with sugar - Lipid A (endotoxin) is released upon Gram-negative cell death - sugars of LPS differ between bacterial strains

supercoils (5)

- unzipping/unwinding action of helicase introduces supercoil into the DNA molecule ahead of the replication fork - excessive supercoiling creates tension on the DNA molecule & could stop DNA replication - Gyrase and Topoisomerase removed supercoils —> cut DNA and rotate cut ends in the direction opposite of the coiling —> rejoin the cut ends

Transformation - Types of Horizontal Gene Transfer

- uptake of extracellular DNA by a competent bacteria (ex. DNA from dead organisms) - also occurs in vitro

Antisepsis (antiseptic)

- use of antiseptic chemicals on living tissue to destroy some microbes/viruses/pathogens

Disinfection (3)

- use of disinfectants for the "destruction of most microbes/viruses/pathogens on nonliving tissue" - does not guarantee that all pathogens are eliminated (unlike sterilization) - alone, can't inhibit viruses/endospores

Transport media - 6 types of culture media (2)

- used by health care personnel to ensure clinical specimens are not contaminated and to protect people from infection - Transport media are designed to keep microbes stable until they can be inoculated into appropriate growth media. - rapid transport of samples is important

Pasteurization - Moist Heat Methods (2)

- used for milk, ice cream, yogurt, fruit juices - this is NOT sterilization (heat-tolerant/loving microbes survive)

photolyases (light repair enzymes) (4)

- used in Light Repair (direct repair) - prokaryotes - repair Thymine Dimers (from UV light) - use energy from visible light to break Dimer bonds - "light repair mechanism"

mismatch-repair enzymes (4)

- used in Mismatch Repair (single-strand repair) - scans new DNA for mismatches and repairs it - these enzymes recognize new DNA from the lack of methylation that DNA acquires from the cell over time - cannot repair methylated DNA

excision-repair enzymes (6)

- used in Nucleotide-Excision Repair (single-strand repair) - excise/cut out damaged DNA - often clip out neighboring nucleotides - DNA polymerase and DNA ligase fill in gaps - called "Dark Repair" when fixing Thymine Dimers - can occur with/without light present

Formalin - Aldehydes (4)

- used in embalming and disinfection of rooms and instruments - formaldehyde + water = 37% Formalin solution - Irritates mucous membranes - carcinogenic

Carbohydrate Utilization (4)

- used to determine fermentation - each tube contains a single kind of sugar as a carbon source and dye phenol red as a pH indicator - if the carb is not fermented, no acid produced, the medium is red - if the carb is fermented, enough acid is produced to turn the phenol yellow

Moist Heat (3)

- used to disinfect, sanitize, sterilize, and pasteurize - denature proteins and destroys cytoplasmic membranes - more effective than dry heat because water conducts heat better than air

Microbial Death Rate

- used to evaluate effectiveness of antimicrobial agents - logarithmic; if 90% of a population is killed in 1 minute, 90% of the remaining population is killed the next minute - usually found to be constant over time for any particular microorganism under a particular set of conditions

Inducible Operons (3)

- usually inactive; must be "turned on" by inducers - often code for proteins that transport/catabolize sparsely available nutrients - often involved in controlling catabolic pathways whose polypeptides are not needed unless a particular nutrient is available.

What is the end of each arm called? (3)

- variable region - the ends of BCRs on any one B cell differ from the ends of any other B cell's BCRs --> the AA sequence varies among B cells

Adaptive Immunity

- vertebrate's ability to recognize and then mount a defense against specific invaders and their products

Provirus

- viral DNA that has attached to a host cell's chromosome and that is replicated with the chromosome's DNA - the genetic material of a virus as incorporated into, and able to replicate with, the genome of a host cell

After entry, what do viral enzymes do to bacterial DNA? (3)

- viral enzymes degrade the bacterial DNA into its constituent nucleotides - the bacteria has lost its chromosome and it stops synthesizing its own molecules - bacteria only synthesizes viral parts under the control of the viral genome

Why can it be difficult to treat viral diseases? (2)

- viral replication uses cell structures/pathways involved in the growth and maintenance of healthy cells - any strategy that disrupts viral replication can disrupt normal cellular processes as well

Length of Incubation Period Depends On: (5)

- virulence of infective agent - infective dose (initial number of pathogens) - state and health of patient's immune system - nature of pathogen and its reproduction time - site of infection

Why can't viruses be grown in standard microbiological broths or on agar plates? (2)

- viruses cannot metabolize or replicate by themselves - must be cultured inside suitable host cells

Genetic Material of Viruses - differences in viruses (9)

- viruses have more genome variety than cells - type of genetic material is the primary way viruses are classified - viruses may be DNA or RNA (never both) --> dsDNA, ssDNA, dsRNA, ssRNA - viral DNA is NOT methylated - can be linear/segmented (like euk.) OR single/circular (like prok.) - much smaller genome than cells --> smallest bacteria has 1,000 genes --> smallest virus has 3 genes

Viral Generalists (2)

- viruses that may infect many kinds of cells or many different hosts --> West Nile Virus (WNV) infects mammals, birds, reptiles, and amphibians

Hydrostatic Pressure (3)

- water exerts pressure in proportion to depth - for every 10 m, water pressure increase 1 atmosphere (atm) (100 m below is 10 times greater than at the surface) - Barophiles live under extreme pressure

cells' water needs (5)

- water is required to dissolve enzymes and nutrients - water is an important reactant in metabolic reactions - most cells die without water - some have cell walls that retain water (months of survival) - in emergency, endospores and cysts can form and cease most metabolic activity then survive for years

Nonionizing Radiation

- wave greater than 1 nm; not enough energy to force electrons out of orbit - enough energy to excite electrons to form new covalent bonds - affects 3D structure of proteins/nucleic acids - ex. UV, visible, infrared, radio

Mycolic Acids (4)

- waxy lipid - helps cells survive desiccation (drying out) - makes cells difficult to stain w/ water-based dyes - found in Mycobacterium such as in the causative agents of TB and leprosy

Positive Regulation by CAP - 1st step of inducing lac operon (5)

- when glucose is low, cAMP accumulates in E. Coli and acts as glucose starvation signal - cAMP binds to CAP - CAP binds to sites on DNA near operons controlling sugar metabolism (lac) - with CAP attached to CAP-site, RNA polymerase is more attracted to lac's promoter - CAP enhances lac transcription in the absence of glucose

Leukocytes (3)

- white blood cells - Involved in defending the body against invaders - Divided into granulocytes and agranulocytes

Systemic Infection (2)

- widespread infection in many systems of the body - often travels in the blood or lymph

Deep-freezing - 3 ways to preserve cultures (2)

-50 to -95 C (-58 to -139 F) - stores for years

Scientists number the carbon atoms in a nucleotide's sugar component as:

1 ' (pronounced "one prime") through 5 ' (pronounced "five prime") (Figure 7.1)

The carbon atoms of deoxyribose are number __ ' through ___ '.

1 ' through 5 '

Endospore formation steps (8)

1) DNA is replicated 2) DNA aligns along the cell's long axis 3) cytoplasmic membrane invaginates to form forespore (two separate plasma membranes within the cell wall) 4) cytoplasmic membrane grows and engulfs forespore within a second membrane -vegetative cell's DNA disintegrates 5) a cortex of calcium and dipicolinic acid is deposited between the membranes 6) spore coat forms around endospore 7) endospore matures: completion of spore coat and increase in resistance to heat and chemicals by unknown process 8) endospore is released from original cell

* About one of every ___ genes contain an error. Mutagens increase this to one every ___ to ___ genes.

1) about one of every 10^7 (10 million) genes contain an error 2) 10^6 3) 10^4 - Mutagens increase the mutation rate by a factor of 10 to 1000 times

4 Types of Eukaryotic DNA polymerases

1) initiates replication, including primer synthesis (compared to bacterial primase) 2) replicates the leading strand 3) replicates the lagging strand 4) replicates mitochondrial DNA

Types of Eukaryotic Nuclear RNA Polymerase (4)

1) transcribes mRNA 2) transcribes the major rRNA gene 3) transcribes tRNA and smaller rRNA molecules 4) mitochondria used a fourth type of RNA polymerase

Microbial Death Rate Example

1,000 cells are in a broth. The antimicrobial agent will kill 90% of them in 1 minute. Death rate is logarithmic. 1 minute exposure results in 900 dead cells, 100 living cells. An additional minute will kill 90% of the remaining 100 cells. 2 minute exposure results in a total 990 dead cells, 10 cells remain. 3 minutes results in 999 dead cells, 1 cell remains. 4 minutes results in a sterile broth with 100% of the 1,000 cells dead. If plotted, the rate is a straight line showing constant microbial death.

Antibodies Function in Several Ways

1. Activation of complement and inflammation 2. Neutralization 3. Opsonization 4. Agglutination 5. Antibody-dependent cell-mediated cytotoxicity (ADCC)

Steps of Activation of Tc (Cytotoxic T) Cell Clones and Their Functions (PROFESSOR NOTES)

1. Antigen Presentation - DOUBLE activation of T cells - Th cell binds via CD4 to MHC II of APC. - Then the APC will secrete an IL-12. 2. Helper T cell Differentiation - Th cell is activated and secretes IL-2 to activate Tc cells 3. Clonal Expansion - Tc cell clone 'army' is made, a small amount remain as memory 4. Self Stimulation - Secrete IL-2 to stimulate their own proliferation and activation

Steps of Activation of Tc (Cytotoxic T) Cell Clones and Their Functions (BOOK)

1. Antigen presentation - APCs present epitopes in conjunction with (MHC II to Helper T cells) OR with (MHC I to Cytotoxic T cells) - immunological synapse; Tc binds to dendritic cell - CD8 glycoprotein of the Tc cell, which specifically binds to MHC I protein, stabilizes the synapse 2. Helper T cell differentiation - nearby CD4-bearing helper T (Th) lymphocyte assists by binding to MHC II on the dendritic cell via the TCR of the helper cell - Association with a helper T cell induces the APC to more vigorously signal the Tc cell - Infected APCs secrete IL-12, which causes helper T cells to differentiate into Th1 clone cells - Th1 cells in turn secrete IL-2 - Lacking the assistance of Th cells, an immunological synapse between the APC and the Tc cell fails --> This limits improper immune responses 3. Clonal expansion - Signaling from the APC and IL-2 from the Th1 cell activate Tc cells that recognize the MHC I protein-epitope complex - IL-2 triggers Tc cells to divide, forming a clone of active Tc cells as well as memory T cells (clonal expansion) 4. Self-stimulation - Active Tc cells secrete IL-2, becoming self-stimulatory - no longer require either an APC or a helper T cell - They leave the lymph node and are now ready to attack virally infected cells

Koch's Postulates

1. The suspected agent (bacterium, virus, etc.) must be present in every case of the disease. 2. That agent must be isolated and grown in pure culture. 3. The cultured agent must cause the disease when it is inoculated into a healthy, susceptible experimental host. 4. The same agent should be found in the diseased experimental host.

Steps of T-dependent antibody response (LONG)

1. Antigen presentation for Th activation and proliferation - Antigen presentation, in which an APC, typically a dendritic cell, presents antigen to a complementary Th cell - Antigen presentation depends on chance encounters between Th cells and the dendritic cells - Once they have established an immunological synapse, CD4 molecules in membrane rafts of the Th cell's cytoplasmic membrane recognize and bind to MHC II, stabilizing the synapse - a second signal helps prevent accidental inducement of an immune response - APC imparts the second signal by displaying an integral membrane protein in the immunological synapse. This induces the Th cell to proliferate, producing clones 2. Differentiation of helper T cells into Th2 cells - the cytokine interleukin 4 (IL-4) acts as a signal to the Th cells to become type 2 helper T cells (Th2 cells) 3. Activation of B cells - A Th2 cell binds to the B cell with an MHC II protein-epitope complex that is complementary to the TCR of the Th2 cell. - CD4 glycoprotein again stabilizes the immunological synapse - Th2 cells secrete more IL-4, which induces the selected B cell to move to the cortex of the lymph node - Th2 cell in contact with an MHC II protein-epitope on the B cell is stimulated, expresses new gene products, and inserts a protein called CD40L into its cytoplasmic membrane - CD40L binds to CD40, which is found on B cells triggering Clonal Selection 4. Proliferation and Differentiation of B Cells - memory B cells - antibody-secreting plasma cells

8 Stages of Lysogenic Replication Cycle

1. Attachment 2. Entry 3. Prophage 4. Reproduction of host and prophage 5. Induction 6. Synthesis 7. Assembly 8. Release

3 domains of life

1. Bacteria 2. Archaea 3. Eukarya Prokaryotes (domain Archaea, domain Bacteria) Eukaryotes (domain Eukarya)

** 3 Events of Eukaryotic RNA Processing Before Translation (LONG)

1. Capping - cell adds a modified Guanine to the 5 ' of mRNA when the RNA molecule is 30 nucleotides long - allows mRNA to be exported from nucleus 2. Polyadenylation - occurs without a DNA template - when RNA polymerase reaches the end of a gene, termination proteins cleave the RNA molecule and add 100-250 Adenine to the 3 ' end (# depending on the organism) 3. Splicing - newly capped and polyadenylated mRNA molecules are called pre-messenger RNA (pre-mRNA) because they contain Introns (non-coding sequences up to thousands of nucleotides long) - Few Prok. mRNA contain Introns - cell removes Introns to make functional mRNA only containing coding regions called Exons (coding sequences up to150 nucleotides long) - 5 small RNA molecules assoc. w/ about 300 polypeptides to form a spliceosome to splice pre-mRNA into mRNA (removes introns, splicing together exons to produce a functional mRNA molecule) - the pre-mRNA has introns removed, and exons spliced together via a spliceosome

Templating Steps

1. Cell makes c-PrP, which is inserted into the cell's cytoplasmic membrane 2. Incorrectly folded p-PrP may infect the brain or may be produced by an altered c-PrP gene 3. Prion protein (p-PrP) reacts with c-PrP on the cell surface 4. p-PrP converts c-PrP to p-PrP 5. p-PrP molecules continue to convert normal c-PrP into p-PrP

4 steps of binary fission

1. Cell replicates its chromosome they attach to the cytoplasmic membrane. 2. Cell elongates and subsequently separates the DNA. 3. Cell invaginates and forms a new cytoplasmic membrane and wall (septum) across the midline 4. When complete, the daughter cells may remain attached to one another of separate

* Central Dogma of Genetics

1. DNA is transcribed to RNA 2. resulting mRNA is translated to form polypeptides

binary fission - 5 steps

1. DNA replication by "semiconservative replication" 2. Cell grows, cytoplasmic membrane elongates, daughter DNA molecules moved apart 3. Cell invaginates and begins to form a cross wall 4. Cross wall fully formed, daughter cells completely divided 5. Daughter cells MAY separate; parent cell disappears w/ formation of offspring

Taxonomy Review Example

1. Domain (Eukarya) 2. Kingdom (Animalia) 3. Phylum (Chordata) 4. Class (Mammalia) 5. Order (Carnivora) 6. Family (Canidae) 7. Genus (Vulpes) 8. Species (Vulpes Vulpes) It's a red fox.

5 Stages of Infectious Disease

1. Incubation Period (no signs/symptoms) 2. Prodromal Period (vague, general symptoms) 3. Illness (most severe signs/symptoms) 4. Decline (declining signs/symptoms) 5. Convalescence (no signs/symptoms)

* Bacterial Transcription (3 steps)

1. Initiation of Transcription 2. Elongation of the RNA Transcript 3. Termination of Transcription

3 important electron carriers

1. NAD+ (oxidized) —> NADH (reduced) Nicotinamide adenine dinucleotide 2. NADP+ —> NADPH Nicotinamide adenine dinucleotide phosphate 3. FAD —> FADH2 Flavine adenine dinucleotide

4 Steps of Fever

1. Phagocytes release Pyrogens 2. causing Hypothalamus to release prostaglandin which resets the hypothalamic thermostat 3. Nerve impulses cause shivering, higher metabolic rate, inhibition of sweating, vasoconstriction 4. These processes increase body temp to the point set by the hypothalamic thermostat

Initiation of Transcription - first step of bacterial transcription (5)

1. RNA polymerases (enzymes that synthesize RNA) bind to Promoters (specific DNA nucleotide sequences) - each Promoter is located near the beginning of a gene and serves to initiate transcription - a sigma factor is necessary to recognize promoters - the stronger the attraction between sigma factor and promoter, the better chance that particular gene will be transcribed 2. sigma factors often drop off the RNA polymerase as transcription begins

3 Factors Affecting Efficiency of Antimicrobial Agents

1. Site to be Treated 2. Susceptibility of Microorganisms 3. Environmental Conditions

Koch's Postulates 4 steps

1. The suspected causative agent must be found in every case of the disease and be absent from healthy hosts. 2. The agent must be isolated and grown outside the host (culturing) 3. When the agent is introduced to healthy, susceptible host, the host must get the disease. 4. The same agent must be found in the diseased experimental host

Several Characteristics of Antimicrobials Considered by Medical Personnel

1. Type of Pathogen Antimicrobials Are Effective Against - level of effectiveness - dosages required to be effective 2. Administration Methods 3. Overall Safety 4. Side Effects

4 Steps of Bacterial Conjugation

1. a sex pilus connects a donor (F+) cell to a recipient (F-) cell 2. F plasmid enzyme nicks plasmid DNA; the single strand transfer to recipient (starts with Origin of Transfer) 3. both cells synthesize complementary strands of F plasmid DNA to form complete double-stranded DNA circles 4. F- recipient is now an F+ cell

Difference between Antiseptics and Disinfectants (3)

1. antiseptics on live tissue; disinfectants on inanimate objects 2. disinfectants are more concentrated & can be left on a surface for longer time 3. mostly same components BUT some disinfectants (bleach/steam) are not suitable antiseptics

Budding - Enveloped Animal Virus Release (3)

1. assembled virions are extruded through one of the cell membranes (nuclear, endoplasmic reticulum or the cytoplasmic membrane) 2. each enveloped virion acquires a portion the cellular membrane (viral proteins were inserted here during synthesis) 3. this membrane becomes the viral envelope

5 Stages of the Lytic Reproduction Cycle

1. attachment (of the virion to the host cell) 2. entry (of the virion or its genome into the host cell) 3. synthesis (of new nucleic acids and viral proteins by the host's enzymes/ribosomes) 4. assembly (of new virions within the host) 5. release (of the new virions from host)

DNA Replication Steps (16)

1. cell removes histones from DNA molecule 2. Helicase unzips the double helix by breaking hydrogen bonds of bases to form a Replication Fork 3. DNA polymerase binds to each strand; catalyze synthesis of DNA by the addition of new nucleotides only to a hydroxyl group at the 3 ' end of a nucleic acid 4. nucleotides are added in one direction - 5 ' to 3 ' 5. LEADING STRAND is synthesized continuously TOWARDS REPLICATION FORK 5a. primase forms an RNA primer complementary to the existing strand 5b. RNA Primer provides a 3 ' hydroxyl group for DNA polymerase III 5c. DNA polymerase III covalently bonds nucleotides (using the diphosphate energy release) 5d. DNA Polymerase III proofreads mismatched nucleotides and removes them before synthesis (proofreading exouclease function) 5e. DNA Polymerase I replaces RNA Primer with nucleotides 6. Lagging strand is synthesized in short segments and later joined 6a. Primase synthesizes multiple!! primers (1 every 1-2k bases) 6b. DNA polymerase III proofreads and joins discontinuous segments (Okazaki fragments) that each use a new RNA primer (so each have 1-2k bases) 6c. Nucleotides pair up with their complements 6d. DNA polymerase I replaces Okazaki fragments and RNA primers 6e. DNA ligase seals gaps between fragments to form continuous DNA

6 Stages of Phagocytosis

1. chemotaxis (of phagocyte to microbes) 2. adhesion 3. ingestion (of microbes by phagocytes) 4. maturation (fusion of a series of vesicles including lysosomes) 5. killing (of microbes by enzymes and other chemicals) 6. elimination (exocytosis) ***process is actually continuous and doesn't proceed in a discrete step-wise manner

Steps for Processing Endogenous Antigens (6)

1. each polypeptide is cut into smaller 8-12 AA pieces by proteases 2. the pieces, including the epitopes, move into the endoplasmic reticulum and bind onto complementary antigen-binding grooves of MHC class I molecules that were previously inserted into the membrane of the ER 3. The ER membrane, now loaded with MHC class I proteins and epitopes, is packaged by a Golgi body to form vesicles 4. The vesicles fuse with the cytoplasmic membrane 5. The result is that the cell displays the MHC I protein-epitope complex on the cell's surface **Since every nucleated cell in the body makes MHC class I, each cell displays epitopes from every endogenous antigen and every autoantigen inside that cell. This allows immune cells to detect all the antigens inside cells

3 Stages of Glycolysis

1. energy-investment stage 2. lysis stage 3. energy-conserving stage

5 Steps of Enzyme Activity

1. enzyme associates with its specific substrate molecule 2. enzyme and substrate bind (enzyme-substrate complex); induced-fit model occurs 3. Substrate bonds are broken; 2+ products formed via catabolic reaction (or linked via anabolic reaction) 4. Enzyme dissociates; products diffuse away from reaction site 5. Enzymes assumes original configuration, ready to do it again elsewhere

Biofilm steps (5)

1. free-floating microbes land on a surface and attach 2. cells produce extracellular matrix and secrete quorum sensing molecules 3. when population threshold is met, quorum sensing triggers cells to change biochemistry and shape 4. new cells arrive (possibly new species) and water channels form 5. some microbes escape to possibly form new biofilm

3 Stages of Bacterial Translation

1. initiation 2. elongation 3. termination

Diffusion susceptibility test (Kirby-Bauer) (4)

1. inoculate pathogen as microbial lawn 2. drug-concentrated paper disks are arranged on the plate 3. incubate 4. bacteria grows except where the effective antimicrobial drugs diffuse through the agar (zone of inhibition)

Why is ATP well suited to serve as the primary short term energy carrier in metabolic pathways? (4)

1. it's multifunctional; can serve as a ribonucleotide to synthesize RNA 2. highly water soluble; can accumulate in cells with no ill effects 3. has two levels of energy donation, depending on what's needed for reaction (ATP to ADP) (ATP to AMP) 4. ATP can serve as a phosphate group

Phases of Microbial Population Growth

1. lag phase 2. log phase 3. stationary phase 4. death phase

Ames test steps

1. mixture containing "his−" (histidine auxotroph) Salmonella mutants, rat liver extract, and the suspected mutagen is inoculated onto a plate lacking histidine 2. colonies form IF mutagen reverses the "his-" mutation, producing "his+" mutations (reverent cells) capable of synthesizing histidine 3. control tube shows that the lack of the suspect mutagen doesn't cause the mutation reversion (proves the mutagen is responsible)

Tetrads

Cocci that divide in two planes and remain attached

RNA Processing (from MMB video)

1. modified Guanine is added to the beginning as a cap 2. segments of the RNA that don't code for the protein are removed 3. remaining RNA segments are reconnected 4. extra Adenine are added to the end of the RNA strand, forming a tail 5. completed mRNA leaves nucleus

Steps of Negative Selection to Isolate a Tryptophan Auxotroph (8)

1. mutagen is added to a bacterial suspension 2. inoculate bacteria onto complete medium containing tryptophan 3. mark the plate to maintain colony orientation 4. bacterial colonies grow. a few might be auxotrophs. most wild-types. 5. stamp sterile velvet onto plate, picking up cells from each colony 6. (Replica Plating) stamp replica plates WITH MATCHING ORIENTATION. one plate is a complete medium with tryptophan, the other lacks tryptophan 7. ID colony growing on complete medium but not on lacking medium 8. inoculate auxotroph colony into complete medium

2 Events Induce the lac operon

1. positive regulation by CAP protein 2. deactivation of a repressor molecule

4 Steps of Tears

1. produced in lacrimal glands 2. exit on to through lacrimal ducts 3. enter lacrimal canal 4. exits into nose through nasolacrimal duct

Protozoa classified by their locomotive structures (3)

1. pseudopods (extensions of cell that flow in the direction of travel; also used for feeding) 2. cilia (numerous short protrusions of cell that beat rhythmically to propel the protozoa) 3. flagella (also ext. of cell but are fewer, longer and more whip-like)

Bacterial Transduction (7 steps)

1. to reproduce, a bacteriophage attaches to bacterial host cell and injects its genome 2. phage enzymes degrade bacteria's DNA 3. phage genome now controls cell function and synthesizes phage DNA and phage proteins 4. cell synthesizes new phages (prophages) with phage DNA. Mistakenly, some remaining host DNA is used to form Transducing phages 5. host cell lyses, daughter and transducing phages released 6. Transducing phage injects donor DNA into a new host recipient 7. Recipient incorporates donor DNA

What is the function of iron-binding proteins? How is it relative to defense?

1. transporting and storing iron 2. they sequester iron so it's unavailable to invading microorganisms

5 Steps of Lysogeny with Lambda Phage

1. viral DNA enters cell but doesn't immediately destroy host DNA; prophage (inactive viral genome/bacteriophage) 2. prophage codes repressor genes 3. prophage merges with bacterial chromosome 4. all daughter cells of lysogenic cells are infected w/ the nearly inactive virus 5. a prophage and its descendants may remain part of the bacterial chromosome for generations or forever

Actions of Alpha and Beta Interferons (picture)

1. virus infects cell 2. viral components trigger activation of type I IFN genes 3. IFN alpha and bet are released and bind to receptors on the same and nearby cells 4. Binding activates genes for AVPs, though AVPs remain inactive at this time (IN NEIGHBOR UNINFECTED CELLS) 5. Infected cell dies, releasing viruses 6. If a new cell is infected, viral components activate the AVPs (that were already in there by step 4) 7. Active AVPs degrade mRNA and bind to ribosomes, which stops protein synthesis, preventing viral replication

The cytoplasmic membrane of a professional APC has about ___ MHC II molecules

100,000

Micrometer (um)

10^-6 - one millionth of a meter

Nanometer (nm)

10^-9 - one billionth of a meter

Nitrogen makes up about ___% of the dry weight of microbial cells.

14%

Within the peptidoglycan layer, the crossbridges that connect the chains of alternating sugar molecules extend between ___. - 2 NAM molecules - 2 NAG molecules - a NAG acid and a NAM acid - 2 glucose molecules

2 NAM molecules (provides structural integrity of the peptidoglycan layer)

Fermentation supplies how much ATP?

2 molecules

Gram-positive flagella have ___ rings in the basal body. They are attached to the ____. (2)

2 rings (one pair) cytoplasmic membrane

How are naked animal viruses released?

2 ways: - extruded by exocytosis - they cause cell lysis (like bacteriophage release)

Correctly order the steps involved cellular immunity: 1) The Tc recognizes the infected host cell 2) The Tc interacts with epitope presented by MHC-I on the dendritic cell 3) The Tc secretes perforin and granzyme, causing apoptosis 4) The helper T cell activates the Tc cell

2, 4, 1, 3 2) The Tc interacts with epitope presented by MHC-I on the dendritic cell 4) The helper T cell activates the Tc cell 1) The Tc recognizes the infected host cell 3) The Tc secretes perforin and granzyme, causing apoptosis

Place the following steps of phagocytosis in the order that they occur: 1) Endosome fuses with lysozome 2) Dendritic cell engulfs Rhinovirus 3) Epitopes are attached to MHC-II 4) Digestion of the Rhinovirus 5) MHC-II plus the attached epitope move to the outside of the dendritic cell

2,1,4,3,5 2) Dendritic cell engulfs Rhinovirus 1) Endosome fuses with lysozome 4) Digestion of the Rhinovirus 3) Epitopes are attached to MHC-II 5) MHC-II plus the attached epitope move to the outside of the dendritic cell

Anaerobic respiration supplies how much ATP?

2-36 molecules

DNA polymerase can only add bases to which end of the DNA strand? (5)

3 ' - this means DNA polymerase can only bases to a nucleic acid (can't start replication from scratch) - DNA polymerase interacts with an RNA primer at the 3 ' end - DNA polymerase catalyzes the addition of bases to the 3 ' end of a growing DNA molecule - catalyst reaction is power by high-energy bond of the nucleotide triphosphates

E. Coli has how many base pairs in its genome?

4.6 x 10^6 bp -it's 800 times longer than the cell itself

If you begin with six cells, how many cells would you have after three rounds of division?

48

* How many different DNA polymerases do Prokaryotes have?

5

At which point does a recipient cell become an F+ cell? 1. Fusion of the cell membranes 2. Attachment of the sex pilus 3. Transfer of the single stranded F factor 4. Pulling of donor and recipient cells together 5. Formation of the complementary strand of the F factor

5. Formation of the complementary strand of the F factor

How many codons code for the amino acid arginine? - 3 - 4 - 1 - 6

6 - Arginine and leucine each have six codons, more codons than any other amino acid.

A medium designed to change color in order to indicate growth of certain types of bacteria would be considered a __________.

A differential medium shows different results for different organisms.

fragmentation

A means of asexual reproduction whereby a single parent breaks into parts that regenerate into whole new individuals, identical to the parent cells.

Which of the following statements regarding the cell-mediated immune response is TRUE? - Helper T lymphocytes have no role in the activation of cytotoxic T lymphocytes. - Cytotoxic T lymphocytes interact with antibodies that have bound antigen to identify their target. - Cytotoxic T lymphocytes kill by producing hydrogen peroxide. - Cytotoxic T lymphocytes do not require antigen presentation to become activated. - A single cytotoxic T lymphocyte can kill many target cells.

A single cytotoxic T lymphocyte can kill many target cells

What would happen if the mRNA codon that coded for Cys was mutated in the third position from a U to an A? - The codon would now code for Trp instead of Cys. - The amino acid Cys would still be coded. - A stop codon would be introduced prematurely

A stop codon would be introduced prematurely

Endospores (7)

A thick-walled protective spore that forms inside a vegetative bacterial cell and resists harsh conditions. - the transformation process is called "sporulation" and takes 8-10 hours - depending on the species it can form centrally, subterminally (near one end), or terminally (at one end) - extremely resistant to drying, heat, radiation and lethal chemicals - not completely unerstood - can survive tens of thousands of years (or millions) ex. anthrax, tetanus, gangrene

start codon (4)

AUG - codon that signals to ribosomes to begin translation - can code for the amino acid methionine - acts as a start codon for N-formylmehionine (a modified amino acid) in bacteria, mitochondria, and chloroplasts

Pathogenicity

Ability of a microorganism to cause disease

Which of the following is NOT a step that ultimately leads to antibody production? - Immature B cells conducting surveillance for foreign epitopes - Differentiation of plasma cells - Activation of helper T cells by dendritic cells - Activation of cytotoxic T cells by helper T cells

Activation of cytotoxic T cells by helper T cells - The activation of cytotoxic T cells leads down the path of cell-mediated immunity.

Active or Passive Acquired Immunity

Active - either the immune system responds actively to antigens via antibody or cell-mediated responses Passive - or the body passively receives antibodies from another individual

Which of the following statements is true? - Memory B cells are typically established when the B cell binds to an antigen. - Adaptive defenses include both humoral and cellular immunity. - Adaptive defenses include humoral immunity only. - Innate defenses are enough to keep a person healthly

Adaptive defenses include both humoral and cellular immunity - This answer is correct. Adaptive defenses are operating optimally when both humoral and cellular immunity are working together in response to a pathogen.

During DNA replication, which nucleotide will bind to an A nucleotide in the parental DNA?

Adenine binds to Thymine (A-T) DNA (A-U) RNA (G-C) DNA

Exons - book definition (2)

Coding sequence of mRNA - exons are connected to produced a functional mRNA molecule

Vehicle Transmisison

Airborne transmission - When pathogens travel more than 1 m via an aerosol - Aerosols can occur from various activities --> Sneezing, coughing, air-conditioning systems, sweeping Waterborne transmission - Important in the spread of many gastrointestinal diseases - Fecal-oral infection Foodborne transmission - Spread of pathogens in and on foods - Inadequately processed, cooked, or refrigerated foods - Foods may become contaminated with feces Bodily fluid transmission - Bodily fluids such as blood, urine, and saliva can carry pathogens - Prevent contact with conjunctiva or breaks in the skin or mucous membranes

Review - A nurse is preparing a patient's arm for an injection. She swabs the area thoroughly with 70% ethanol. What cleaning method is the alcohol? What cleaning method is the physical swabbing? Which removes the most microbes?

Alcohol - antiseptic (on live tissue) Swabbing - degerming The physical degerming (swabbing) removes the most microbes.

Which of the following statements is NOT accurate about prokaryotic and eukaryotic genomes? - Most bacteria and archaea have circular DNA in the cytoplasm, while most eukaryotes have linear DNA in the nucleus. - Archaea and eukaryotes have histone proteins associated with their DNA, while bacteria do not have histones. - The chromosomes and plasmids in bacteria, archaea, and eukaryotes contain double-stranded DNA. - All of the DNA in eukaryotic cells is contained within a nucleus.

All of the DNA in eukaryotic cells is contained within a nucleus. - Some eukaryotes have plasmids in their cytoplasm, as well as circular DNA molecules within their chloroplasts and mitochondria.

What is the inducer molecule in the lac operon? - Glucose - Repressor proteins - Lactose - Allolactose - Galactose

Allolactose

Figure 1.6 - Which protozoa uses Pseudopods?

Amoeba proteus

What is meant by the clonal expansion of a B cell? - An activated B cell will immediately begin to produce antibodies. - An activated B cell will engulf and digest anything foreign. - An activated B cell will kill infected host cells. - An activated B cell divides into cells that give rise to memory B cells and plasma cells.

An activated B cell divides into cells that give rise to memory B cells and plasma cells. - This answer is correct. The activated B cell divides until there are many clones. Some differentiate into memory cells, other become plasma cells that produce and secrete antibodies.

Reverse Transcriptase

An enzyme encoded by some certain viruses (retroviruses) that uses RNA as a template for DNA synthesis.

* MHC I and II are nonspecific. What determines their binding diversity? (5)

An individual's genes! - Some epitopes won't be bound to the MHC of a particular person --> such epitopes typically don't trigger an immune response - MHC molecules determine which epitopes might trigger immune responses - explains why some people are allergic to peanuts and others are not

Budding

An outgrowth of the original cell receives a copy of DNA and enlarges and eventually cuts off from the parent cell, typically while it's still quite small

How is ADP reformed?

Anabolic pathways use some energy of ATP by breaking a phosphate bond (which reforms ADP). ATP molecules store energy from catabolic reactions. ATP releases stored energy to drive cellular processes and becomes ADP again.

Which cells possess MHC class II proteins? - All white blood cells - Nucleated cells - Antigen-presenting cells - Red blood cells

Antigen-presenting cells ONLY

Who discovered the bacterial world? (4)

Antoni van Leeuwenhoek (1632-1723) - turned his handmade microscope on a drop of water - started making microscopes in the 1670s - often made a new microscope for each specimen

What are the 3 Domains?

Archaea, Bacteria, Eukarya

What do the differences between archaeal and bacterial flagella mean?

Archaeal flagella arose independently of bacterial flagella; they are analogous structures- having similar structure without having a common ancestor.

How does an autoclave work?

As steam enters an autoclave chamber, it forces air out, raises the temperature of the contents, and increases the pressure until a set temperature and pressure are reached.

Collecting urine

Aseptic collection - catheter inserted into bladder through urethra "clean catch" - initial urination washes the urethra and the specimen is the midstream urine

GAU codes for: - isoleucine. - serine. - aspartic acid. - proline. - tryptophan.

Aspartic Acid

Which of the following statements about lymphocytes is FALSE? - Lymphocytes have different types of CD molecules in their cytoplasmic membranes. - Once they are mature, they migrate to secondary lymphoid organs. - B and T lymphocytes can be differentiated using a bright-field light microscope. - Lymphocytes have integral surface proteins by which they can be recognized. - The glycoproteins on the surface of a lymphocyte are designated with the prefix CD, for "cluster of differentiation."

B and T lymphocytes can be differentiated using a bright-field light microscope - FALSE STATEMENT

Review - Which lymphocyte controls Humoral immune response?

B cells

Which pair of molecules do NOT directly interact with one another? - CD4 and MHC-II - BCR and TCR - CD8 and MHC-I - BCR and epitope

BCR and TCR - Both of these molecules interact with epitopes. BCRs interact with epitopes on the whole pathogen. TRCs interact with processed epitopes when presented on MHC-II.

Review - Type of Nucleic Acid for Bacteria, Archaea, Eukaryotes

Bacteria - circular or linear DNA Archaea - circular DNA Eukaryotes - linear DNA in nucleus and chloroplasts Eukaryotes - circular DNA in mitochondria and plasmids

Review - Plasmids present? Bacteria, Archaea, Eukaryotes

Bacteria - in some cells; frequently more than one per cell Archaea - in some cells Eukaryotes - in some fungi, algae, and protozoa

Review - Histones Present? Bacteria, Archaea, Eukaryotes

Bacteria - no (chromosome IS assoc. w/ small amount of nonhistone protein) Archaea - yes Eukaryotes - yes in nuclear chromosomes; no in extranuclear chromosomes

Review - Location of DNA for Bacteria, Archaea, Eukaryotes

Bacteria - nucleoid of cytoplasm; in plasmids Archaea - nucleoid of cytoplasm; in plasmids Eukaryotes - nucleus; mitochondria, chloroplasts, plasmids in cytosol

Review - # of chromosomes for Bacteria, Archaea, and Eukaryotes

Bacteria - single (haploid) copies of one or more chromosomes Archaea - one chromosome (haploid) Eukaryotes - Two or more chromosomes, typically diploid

What 2 microbes are prokaryotic? (4)

Bacteria and Archaea - both reproduce asexually - most are much smaller than eukaryotic cells - live in nearly every habitat w/ sufficient moisture

How are pili different from bacterial flagella?

Bacterial flagella are flexible structures that rotate to propel the cell; pili are hollow tubes used to transfer DNA from one cell to another.

The alternative pathway of complement cascade activation begins with ________ binding to the surface of a microbe. - factor B - C3b - C5b - C5a - C1

C3b

Which event happens first during cytotoxic T-cell activation? - Clonal proliferation - Secretion of granzymes and perforin - Production of IL-2 and gamma-interferon receptors - CD8 binds to MHC molecules of infected cells

CD8 binds to MHC molecules of infected cells

Review - What provides significant nonspecific defense against pathogens? (3)

COMBO OF: - barrier function of epidermis - continual replacement of epidermis - phagocytic dendritic cells

What yeast causes yeast infections in women?

Candida albicans

Low-oxygen culture - 2 special culture techniques (3)

Candle jars - culture plates are sealed in a jar along with a lit candle - the flame consumes oxygen and releases CO2

2 Major Pathways of Metabolic Reactions (6)

Catabolism - break larger molecules into smaller products - Exergonic (release energy) Anabolism - synthesize large molecules from products of catabolism - Endergonic (consume energy)

induced-fit model (3)

Change in the shape of an enzyme's active site that enhances the fit between the active site and its substrate(s) - enzymes' active sites change shape slightly when they bind to their substrate; to more closely match the substrate shape - almost as if a lock could grasp its key once inserted

Virulence Factors (definition) (6)

Characteristics that allow microbes to be pathogens, including the abilities to: - enter body - adhere to body cells - gain access to nutrients - escape detection - protect from the immune system - interfere w/ normal anatomy and physiology

Which of the following would you likely see on the surface of a human dendritic cell following phagocytosis of a bacterium? - Class II MHC with dendritic cell antigens - Class II MHC with engulfed bacterial antigens - Class I MHC with dendritic cell antigens and - - Class II MHC with engulfed bacteria - Class I MHC with dendritic cell antigens

Class I MHC with dendritic cell antigens and Class II MHC with engulfed bacteria

What would a virally infected skin epithelial cell have on its cell surface? - Class II MHC with liver cell antigens - Class I MHC with skin cell antigens - Class II MHC with viral antigens - Class II MHC with macrophage antigen

Class I MHC with skin cell antigens

What purpose does clonal deletion serve? - Clonal deletion destroys T cells with receptors complementary to the body's normal autoantigens. - Clonal deletion ensures that no two T cells are alike. - Clonal deletion destroys cancerous T cells. - Clonal deletion safeguards against making too many T cells.

Clonal deletion destroys T cells with receptors complementary to the body's normal autoantigens - The process of clonal deletion will eradicate any T cell generated against self, and thus any progeny (clones) that cell may have produced.

A person who has AIDS contracts rare and often life-threatening infections because their helper T cell count is so low. Which of the following components of the immune response still respond to antigen despite the low helper T cell count? - Clonal expansion and antibody production - Activation of cytotoxic T cells - Apoptosis of infected host cells - Clonal selection of B cells

Clonal selection of B cells - B cells can still bind to antigen, which is the process of clonal selection. However, without a helper T cell, clonal expansion and antibody production will not occur.

How does the microbiome protect the body?

Competitive Inhibition (microbial antagonism) 1. Members of the microbiome consume nutrients, making them unavailable to pathogens 2. Microbiome can change the pH of regions of the body, creating an environment that is favorable for themselves but unfavorable to other microorganisms, such as acid in the vagina 3. Microbiome can attach to all of the sites on human cells, blocking pathogens from attaching 4. Microbiome stimulates the body's second line of defense, boosting the body's production of antimicrobial substances --> Researchers have observed that animals raised in an axenic environment—that is, one free of all other organisms or viruses—are slower to defend themselves when exposed to a pathogen 5. Members of the microbiome can themselves generate antimicrobial compounds to defend their "turf," the human body 6. Nutritionally, the resident microbiota of the intestines improve overall health by providing several vitamins, including biotin (vitamin B7)(vitamin B7) and pantothenic acid (vitamin B5),(vitamin B5), which are important in glucose metabolism; folic acid, which is essential for the production of the purine and pyrimidine bases of nucleic acids; and the precursor of vitamin K, which has an important role in blood clotting

Partially digested yeast, which has varying chemical elements, is added to a medium that has been created with exactly measured ingredients. What type of media has been produced? - selective media - defined media - differential media - complex media

Complex media - The exact proportion and types of at least one content of complex media are not precisely known

Lymphatic Vessels

Conducts lymph from tissues and returns it to the circulatory system

2 Types of Regulatory Mechanisms

Control of Gene Expression - cells control amount and timing of protein (enzyme) production Control of Metabolic Expression - cells control activity of proteins (enzymes) once produced

Methylation roles

Control of Genetic Expression - Some methylated genes are "turned off" and not transcribed - Some are "turned on" and transcribed Initiation of DNA Replication - In many bacteria, methylated nucleotide sequences can initiate DNA replication Protection Against Viral Infection - Methylation at specific sites in the nucleotide sequence allows cells to distinguish their DNA from viral DNA (which lacks methylation). - Cells can then selectively degrade viral DNA - methylation can help distinguish new DNA for Mismatch Repair

In a microbiology laboratory, what does culturing mean? - Culturing is the act of producing media. - Culturing is the process of studying microbes from textbooks. - Culturing involves growing microbes in the lab. - Culturing involves sterilizing media in the laboratory.

Culturing is the act of growing microbes in a scientific setting.

Which cells directly attack abnormal cells in the body? - B cells - Helper T cells - Cytotoxic T cells - Phagocytes

Cytotoxic T cells

HIV directly infects T-cells. Why is this problematic for cell-mediated immunity? - HIV causes cytokines to be produced at much higher levels, altering the normal function of the immune system. - HIV transforms the T-cells into cancer cells. - HIV reprograms these cells to attack the body cells. - Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body.

Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body.

Answer to Decimal Reduction Time Example (from book)

D = 5 minutes; thermal death time = 22.5 minutes.

Transcription (3)

DNA --> RNA - copy of a gene is made first before converting DNA info into proteins - the info in DNA is copied as RNA nucleotide sequences (messenger RNA)

What structures do DNA nucleotides and RNA nucleotides have in common? (3)

DNA and RNA nucleotides are each composed of a pentose sugar, a phosphate, and a nitrogenous base Nucleotide = nucleoside + phosphate Nucleoside = pentose sugar + nitrogenous base

What seals the gaps between the DNA fragments created during the synthesis of the lagging strand?

DNA ligase

Which statement about DNA replication is FALSE? - Because the two strands of parental DNA run in opposite directions, the new strands must be made in different ways. - DNA ligase adds nucleotides to the lagging strand. - The lagging strand is made of a series of pieces that must be joined together to make a continuous strand. - DNA polymerase builds a new strand by adding DNA nucleotides one at a time. - The two strands of parental DNA are separated during DNA replication.

DNA ligase adds nucleotides to the lagging strand (is a false statement) - You're right! This statement is FALSE. DNA ligase seals the gaps between segments of DNA in the lagging strand. It does not add nucleotides to the lagging strand

The molecule that seals the gaps between the pieces of DNA in the lagging strand is: - DNA ligase. - DNA polymerase. - the replication fork. - RNA. - the leading strand.

DNA ligase seals the gaps between the pieces of DNA in the lagging strand, turning it into a continuous strand.

Which of the following build(s) new strands of DNA? - The lagging strand - The leading strand - The origins of replication - DNA polymerases - Parental DNA

DNA polymerases build new strands of DNA by adding DNA nucleotides one at a time.

Recombinant DNA

DNA produced by combining DNA from different sources (through genetic recombination)

homologous sequences

DNA segments that are composed of identical or nearly identical nucleotide sequences

Which of the following are likely to be found on an MHC-I protein? - Membranes from a neighboring dead host cell - Bacterial flagella - Damaged mitochondrial fragment - Bacterial DNA - Bacterial cell wall fragment

Damaged mitochondrial fragment

Which of the following is NOT a step in bacterial cell division? - Replication of the genetic material - Cell elongation - Splitting apart of two new daughter cells - Disappearance of nuclear envelope

Disappearance of nuclear envelope (they don't have a nucleus!)

What bonds link the heavy and light chains together?

Disulfide bonds, which are covalent bonds between sulfur atoms in adjoining amino acids

Why do lymph nodes enlarge during an infection?

During an infection, lymphocytes multiply profusely in lymph nodes. This proliferation and swelling cause lymph nodes to enlarge.

Why do cells trail behind their optimum reproductive potential during the lag phase?

During the lag phase, cells are synthesizing thhe metabolic machinery and chemicals required for optimal reproduction.

Understanding DNA replication comes largely from studying what bacterium?

E. Coli

Biosafety levels

Each level raises personnel and environmental safety by specifying increasingly strict laboratory techniques, use of safety equipment, and design of facilities. (BSL-1) (BSL-2) (BSL-3) (BSL-4)

semiconservative replication - of binary fission (2)

Each molecule of DNA consists of one strand of the original DNA and one strand of the new DNA. Each DNA molecules remains attached to the cytoplasmic membrane.

How can a sufficient humoral immune response occur if a plasma cell only lives for a few days? - T cells can also produce antibodies. - Each plasma cell can produce up to 2000 antibodies every second. - Each plasma cell can proliferate into more plasma cells. - Memory B cells can also produce antibodies

Each plasma cell can produce up to 2000 antibodies every second

Review - Why are eggs often used to grow animal viruses?

Eggs are large, sterile, self-sufficient cells that contain a number of different sites suitable for viral replication.

Which of the following steps of transcription is INCORRECTLY paired with its function? - Elongation: RNA polymerase links nucleotides to the 3′ end of the growing transcript. - Initiation: RNA polymerase binds to the promoter region of DNA. - Elongation: RNA polymerase synthesizes a transcript from both strands of DNA to create multiple copies. - Termination: RNA polymerase and the transcript are released from DNA by self-termination or Rho-dependent termination.

Elongation: RNA polymerase synthesizes a transcript from both strands of DNA to create multiple copies.

In which location within the cell are epitopes bound to MHC class I proteins? - Nucleus - Golgi body - Endoplasmic reticulum - Cytoplasm

Endoplasmic reticulum - It is within the endoplasmic reticulum that endogenous antigen is bound to the MHC class I protein.

Active Processes

Energy (ATP) required - Active Transport (by carrier proteins called "permeases") - Group Translocation

Glycolysis Energy Summary

Energy-investment stage: -2 ATP Energy-conserving stage: +4 ATP NET gain: 2 ATP

Generally, viruses are known solely by their (latin or english?) ____names.

English

Role of Enzymes in Metabolism (6)

Enzymes are organic catalysts! - increase likelihood and speed of reactions - they're not change or consumed by the reaction - lower activation energy - enzyme-substrate specificity - 6 categories

If Koch's postulates cannot be applied to a disease condition for whatever reason, how can we positively know the causative agent of a disease?

Epidemiological studies can give statistical support to causation theories but not absolute proof.

When bacteria suffer extreme damage to their DNA, they often resort to a last-chance repair mechanism known as the

Error-Prone Repair (repair of double-strand damage)

As shown in the animation, the start codon also codes for which amino acid? - Proline - Alanine - Methionine - Serine - Glycine

Eukaryotes: Methionine Prokaryotes: N-Formylmethionine

Are fungi prokaryotic or eukaryotic?

Eukaryotic

What is required by an F- cell to become an F+ cell? - F+ chromosome - F plasmid - Conjugation pilus - An F- cell to be a recipient

F Plasmid

What is the key difference between donor cells and recipient cells? - Size - A chromosome - Cell membranes - An F plasmid

F Plasmid

Which of the following is capable of conjugation? - F- cells - F+ and Hfr cells - competent cells - bacteriophages

F+ and Hfr cells

The sigma factor is required for initiation of translation in prokaryotic cells. T/F

False - The sigma factor is necessary for proper recognition of a promoter by RNA polymerase during transcription initiation.

Halophiles grow equally well in the presence or absence of high salt concentrations.

False - optimum range for most is 17-23% salt

Only eukaryotes are susceptible to some sort of viral attack. (3)

False! All types of organisms are susceptible to some sort of viral attack. --> viruses can infect archaeal, bacterial, plant, protozoan, fungal, and animal cells --> tiny viruses can attack specific, larger viruses

All of the eukaryotic genome is contained in its nuclear chromosome. T/F

False! Most eukaryotic cells have mitochondria which contain chromosomes! Plant, algal, and some protozoan cells have chloroplasts which contain chromosomes!

Allosteric sites are only inhibitory. T/F

False! They can be inhibitory (inhibitors) or excitatory (activators)

All bacteria are competent. T/F

False! only a few genera of bacteria are naturally competent ex. streptococcus pnuemoniae are naturally competent ex. E. Coli are artificially made competent in a lab

How is excess iron stored?

Ferritin protein binds to Iron and stores it in the liver.

Regardless of where you live, name a disease that is endemic, one \that is sporadic, and one that is epidemic in your state.

Flu is endemic in every state; tuberculosis is sporadic in most states; AIDS is epidemic in every state.

Why is route of administration important?

For an antimicrobial agent to be effective, an adequate amount of it must reach a site of infection

** How was it proven that DNA is genetic material?

Frederick Griffith was studying Streptococcus pneumoniae. He injected the deadly, encapsulated strain S into mice, killing them. The uncapsulated strain R was less virulent (WBC ate the cells quick). Griffith injected a DEAD strain S and a LIVE strain R into mice. The mice died. Strain R had transformed, assimilating the capsule-coding genes of strain S cells. This discovery was one of the conclusive pieces of evidence that DNA is the genetic material of cells.

How do fungi differ from animals?

Fungi have cell walls

Which of the following would contain teichoic acids? - a Gram-positive cell wall - a Gram-negative cell wall - the glycocalyx - a pseudomurin cell wall

Gram-positive cell wall

Which molecule triggers apoptosis? - IL-2 - Granzyme - Perforin - Gamma-interferon - MHC

Granzyme

7 Viral Groups - based on mRNA synthesis

Group I: dsDNA Group II: ssDNA Group III: dsRNA Group IV: +ssRNA Group V: -ssRNA Group VI: +ssRNA-RT Group VII: dsDNA-RT

Taxa

Groups that organisms are classified into based on shared characteristics ex. two taxa- domain Archaea and domain Bacteria -consist of organisms that are prokaryotic

Viruses in Relation to the 4 Processes of Life (5)

Growth - growth does not occur Reproduction - host cell replicates the virus Responsiveness - reaction to host cells see in some viruses Metabolism - viruses use the host's metabolism Cellular Structure (membrane-bound structure capable of all of the above functions; present in all other living things) - Viruses lack cytoplasmic membrane or cellular structure

"Given that RNA cannot be incorporated directly into a chromosome molecule, how does the ssRNA of HIV become a provirus incorporated into the DNA of its host cell?"

HIV can become a permanent part of a host's chromosome because it, like all retroviruses, carries reverse transcriptase, which transcribes the genetic information of the +RNA molecule to a DNA molecule—which can then become incorporated into a host cell's genome.

How do helper T-cells and cytotoxic T-cells work together? - Cytotoxic T-cells attack abnormal body cells, while helper T-cells attack virally infected cells. - Helper T-cells produce cytokines to activate other cells of the immune system. - Helper T-cells produce cytotoxic T-cells. - Cytotoxic T-cells produce cytokines to activate helper T-cells

Helper T-cells produce cytokines to activate other cells of the immune system

Germicides Classified by Effectiveness

High - kills all pathogens, including endospores (healthcare, high-risk sterilization) Intermediate - kills all fungal spores, protozoan cysts, viruses, pathogenic bacteria (disinfect noninvasive, mucous membrane equipment) Low - kills vegetative bacteria, fungi, protozoa, and some viruses (disinfect items for skin contact only ex. chairs, electrodes)

What is the most common element in cells?

Hydrogen - so common in organic molecules and water that it's never a "limiting nutrient" meaning that metabolism is never interrupted by a lack of hydrogen

What determines which base is added to the 3 ' end of the strand? (3)

Hydrogen bonding between the parental strand and the nucleotide triphosphates - only thymine fits to adenine - only cytosine fits to guanine

Which of the following cytokines promotes the development of a cell-mediated immune response? - IL-4 (interleukin-4) - tumor necrosis factor (TNF) - IL-12 - chemokines - alpha interferon

IL-12

Clonal deletion of T cells

Immature T cells undergo one of four fates 1. T cells that do not recognize body's MHC protein undergo apoptosis 2. T cells that recognize autoantigen die by apoptosis 3. Some "self-recognizing" T cells become regulatory T cells 4. T cells that recognize MHC protein and foreign epitopes become repertoire of protective T cells (don't recognize autoantigen with MHC)

How does budding differ from binary fission?

In binary fission, the parent cell disappears with the formation of two equal-sized offspring; a bud, in contrast, is often much smaller than its parent, and the parent remains to produce more buds.

Where would one find an uncharged tRNA molecule in a ribosome? - In the P and E sites - In the E site - In the A site - In the P site - In the A and P sites - In the A, P, and E sites

In the P and E sites

Immune System Cytokines

Interleukins (ILs) - Signal among leukocytes; 37 Interferons(IFNs) - Antiviral proteins that may act as cytokines - inhibit the spread of viral infections - gamma interferon, (IFN-γ), which is a potent phagocytic activator secreted by type 1 helper T cells Growth factors - Proteins that stimulate stem cells to divide - body can control the progression of an adaptive immune response by limiting the production of growth factors Tumor necrosis factor (TNF) - Secreted by macrophages and T cells to kill tumor cells and regulate immune responses and inflammation Chemokines - Chemotactic cytokines that signal leukocytes to move

Humans require ___ for metabolism. (4)

Iron! - component of cytochromes of electron transport chains - functions as an enzyme cofactor - essential part of hemoglobin

According to the animation, how do the repressor proteins block the transcription of the structural genes? - It binds to the repressor gene when deactivated. - It binds to the repressor when deactivated. - It binds to the operator when activated. - It binds to the promoter when deactivated. - It binds to the promoter when activated. - It binds to the repressor gene when activated.

It binds to the operator when activated.

The envelope found in some virus particles differs from the cytoplasmic membrane of cells in that __________. - it does not perform the physiological functions carried out by the cytoplasmic membrane - it is not as dense as a cytoplasmic membrane - it contains different types of phospholipids than does a cytoplasmic membrane - it is not as flexible as a cytoplasmic membrane

It does not perform the physiological functions carried out by the cytoplasmic membrane - Because viruses are not cells, their envelopes do not carry out the physiological functions of a cytoplasmic membrane, such as endocytosis or active transport.

Which of the following is CORRECT regarding the viral envelope? - It is composed of cellular phospholipid membrane, cellular and viral proteins. - It contains only viral proteins. - It is composed of sterols of viral proteins only. - It is composed of sterols. - It contains only host cell proteins.

It is composed of cellular phospholipid membrane, cellular and viral proteins.

What is the function of the conjugation pilus? - It contains an F plasmid. - It converts F- cells into F+ cells. - It carries the chromosome of F- cells. - It pulls the F+ and F- cells together

It pulls the F+ and F- cells together

protist

Kingdom composed of eukaryotes that are not classified as plants, animals, or fungi

Metabolic Activity - indirect measurement of microbe growth (3)

Known rate of metabolism indirectly estimates # of cells by measuring: - pH - nutrient utilization - waste

Which of the following is a component of a B cell receptor but NOT a T cell receptor? - an antigen-binding site - a transmembrane portion - light chains - a variable region

Light chains are associated only with B cell receptors

Based on the animation, T cells recognized the antigen displayed by what protein of the B cell? - CD4 - MHC - Antigen - TCR - BCR

MHC

T cells recognize epitopes only when they are bound to __________. - CD8 molecules - MHC - other T cells - antibody

MHC - Yes. The major histocompatibility complex proteins are responsible for presenting epitope to T cells

What is the purpose of an MHC class I protein? - MHC class I molecules display epitopes from exogenous antigen. - MHC class I proteins break down endogenous antigen. - MHC class I proteins display epitopes from endogenous antigen. - MHC class I proteins bind antibodies

MHC class I proteins display endogenous antigen, including autoantigen

List some resistant pathogens

MRSA, VRSA, VISA, VRE, MDR-TB, and XDR-TB

Which of the following cells is included as an antigen-presenting cell? - Hepatocytes - Red blood cells - Platelets - Macrophages

Macrophages - The macrophage or "large eater" is responsible for internalizing, lysing, and then presenting exogenous antigen

dsRNA

Made of both +ssRNA and -ssRNA, each used to make complimentary strand - dsRNA virus genome unwinds so that the positive-sense strand serves as mRNA and each strand serves as a template for its complement.

symbionts

Members of a symbiotic relationship

Which of the following does NOT happen above the maximum growth temperature of a microorganism? - Proteins become denatured. - Hydrogen bonds break. - Membranes become rigid and fragile. - Lipids become too fluid.

Membranes become rigid and fragile.

Catabolism

Metabolic pathways that break down molecules, releasing energy.

Anabolism

Metabolic pathways that construct molecules, requiring energy.

Obligate Aerobes (2)

Microorganism that requires oxygen as the final electron acceptor of the electron transport chain, which produce most of the ATP in these organisms. - Algae, most fungi and protozoa, and many prokaryotes

Obligate Anaerobes (2)

Microorganisms that cannot tolerate oxygen and uses a final electron acceptor other than oxygen to produce ATP - many prokaryotes and a few protozoa

2 Direct Methods Not Requiring Incubation - how to measure microbial reproduction (6)

Microscopic Counts —> scientist count directly through a microscope (They need to multiply the mean # of bacteria per square by 1,250,000 to calculate the # of bacteria per milliliter of bacterial suspension) Electronic Counters —> A Coulter Counter directly counts cells as they interrupt an electrical current flowing across a narrow tube held in front of an electronic detector —> useful for large yeasts, unicelluar algae, and protozoa —> not as useful for bacterial counts due to debris in media, filaments and cell clumps

How could antimicrobials targeting 70S prokaryotic ribosomes still be harmful to eukaryotic cells/organisms?

Mitochondria and chloroplast ribosomes are 70S!

2 Heat Methods

Moist Heat Dry Heat

Flagellar Arrangement (6)

Monotrichous - single flagellum Amphitrichous - single flagellum at either end of the cell Lophotrichous - tuft of flagella at one end (counterclockwise, bundle and run; clockwise, open and tumble) Peritrichous - flagella that cover the surface of a cell (ccw, all bundle and run; cw, open and tumble) Polar - flagella are only at the ends Endoflagella - flagella at both ends that spiral around the cell instead of protruding into the surrounding medium (internal flagella)

Morbidity vs. Morality

Morbidity - refers to your risk of health and well-being Morality - refers to your risk of death

Which of the following is NOT a characteristic of the genetic code? - More than one codon is associated with each amino acid. - Most organisms use the same genetic code. - There are 64 possible codons. - More than one amino acid is associated with each codon.

More than one amino acid is associated with each codon.

What are the sugars of peptidoglycan?

N-acetylmuramic acid (NAM) N-acetylglucosamine (NAG)

Are plasmids unique to prokaryotes?

NO

Are virions motile? (2)

NO - all virions (and phages) are nonmotile - their contact with bacteria occurs purely by random collision

What domain are viruses under?

NONE - NO domain - NO kingdom - NO phylum - NO class

What is the smallest known cellular genome discovered to date?

Nasuia deltocephalinicola - is only 112,091 bp long

Review - Which two cells use perforin and granzyme?

Natural Killer cells and Cytotoxic T cells

neutrophil extracellular traps

Neutrophils also generate webs of extracellular fibers nicknamed NETs, for neutrophil extracellular traps. Neutrophils synthesize NETs via a unique form of cellular suicide involving the disintegration of their nuclei. As the nuclear envelope breaks down, DNA and histones are released into the cytosol, and the mixing of nuclear components with membranes and proteins derived from cytoplasmic granules combine to form NET fibers. The neutrophil then kills itself using superoxide and peroxide. The dying cell releases the NETs as its cytoplasmic membrane ruptures. NETs trap both Gram-positive and Gram-negative bacteria, immobilizing them and sequestering them along with antimicrobial peptides, which kill the bacteria. Thus even in their dying moments, neutrophils fulfill their role as defensive cells.

Does "pathogenicity" or "virulence" refer to the severity of a disease?

No! A pathogen could be highly virulent while the disease is relatively mild

Dendritic cells are phagocytic. Are they white blood cells?

No! Dendritic cells await microbial invaders, phagocytize them, and inform cells of adaptive immunity that there is a microbial invasion.

Do all cells die in the death phase?

No, not in every case. The death phase just means that death outweighs reproduction

Are all enzyme protein based? (4)

No, some are RNA molecules called Ribozymes - Ribozymes process other RNA molecules by removing sections of RNA and splicing the remaining pieces together - makes up the functional core of a ribosome - all protein enzymes are made by ribozymes this way

Are all of a bacterium's genes expressed at all times? (2)

No- but many ARE expressed at all times. - They are constantly transcribed and translated and play a persistent role in the phenotype

How do normal prion proteins (PrP) differ from the infectious prion proteins? - Normal PrP are found in all mammals; infectious PrP are found in only cows. - Normal PrP are found on mammals; infectious PrP are found on reptiles. - Normal PrP have alpha-helices; infectious PrP have beta-pleated sheets. - Normal PrP lack nucleic acid; infectious PrP have nucleic acid.

Normal PrP have alpha-helices; infectious PrP have beta-pleated sheets

Review - what is a viral nucleic acid surrounded by its capsid called? What state is it seen in?

Nucleocapsids are seen in the extracellular state

How are nucleotide/nucleoside analogs important medically? (3)

Nucleotide (or nucleoside) analogs make potent antiviral and anticancer drugs. - viruses/cancer replicate faster than normal cells so they quickly incorporate analogs into their DNA and RNA - analog presence is harmful, killing virus/cancer cells faster than they do normal cells

Incidence - Frequency of Disease

Number of new cases of a disease in a given area during a given period of time

Prevalence - Frequency of Disease

Number of total cases of a disease in a given area during a given period of time

** Eukaryotic mRNA can code for how many proteins?

ONLY ONE - prokaryote mRNA can code for more than one protein

Signs

Objective manifestations of disease observed or measured by others

When was the last case of smallpox documented?

October 26, 1977

Which of the following is/are associated with the lagging strand during DNA replication? - introns - codons - Okazaki fragments - Rho protein

Okazaki fragments

Clonality

Once induced, cells of adaptive immunity proliferate to form many generations of nearly identical cells, which are collectively called clones

What portion of bacteriophage T4 enters E. coli? - Only the T4 genome enters the bacterial cell. - No portion of phage T4 actually enters the bacterial cell. - Only the tail fibers penetrate into the interior of the bacterial cell. - The entire phage enters into the bacterial cell.

Only the T4 genome enters the bacterial cell. - The capsid remains on the surface of the cell, and the genome is the only portion to enter the cell.

Dry Weight - indirect measurement of microbe growth (2)

Organisms are filtered from their culture medium, dried and weighed - suitable for broth cultures but can't grow again because the process kills the subjects

Superoxide radicals (2)

Organisms produce superoxide dismutase to detoxify this toxic form of oxygen - this forms hydrogen peroxide (H2O2) and oxygen gas (O2)

During the initiation step of translation, the fMet charged tRNA assembles in which site of the ribosome? - E site - P site - A site

P site

Figure 1.6 - What protozoa uses flagella?

Paranema

What mold produces penicillin?

Penicillium chrysogenum

2 Pathways of Cytotoxic T Cell Killing

Perforin-granzyme pathway - involves the synthesis of special killing proteins - perforins and granzymes are released from Tc cell vesicles - granzymes enter the infected cell via perforin complex pore & activate enzymes of apoptosis CD95 pathway - mediated through a integral glycoprotein (Fas) found on the body's cells - binding of CD95L (receptor) on the Tc cell activates the enzymatic portion of the infected cell's CD95 such that apoptosis is induced

During a lytic replication cycle, what action does a phage take to ensure that its host bacterium does NOT continue synthesizing cellular molecules? - The phage integrates its DNA into the host cell DNA. - Phage enzymes degrade the bacterial DNA. - A phage traps the host DNA in an endosome. - The host DNA is released from the cell.

Phage enzymes degrade the bacterial DNA. - By degrading the host DNA, the phage ensures that only phage proteins are synthesized

antibodies interact with which innate defenses? -I nflammation - Phagocytosis and the complement system - The complement system - First-line defenses - Phagocytosis - Phagocytosis, inflammation, and the complement system

Phagocytosis and the complement system

Which of the following statements concerning conjugation pili is FALSE? - Pili are longer than fimbriae and flagella - Pili are long, hollow tubules - Not all bacteria have pili - A bacterial cell will usually have only one or two pili - Pili facilitate the transfer of DNA among bacterial cells

Pili are longer than fimbriae and flagella

What is produced by the process of clonal expansion? - Plasma cells and memory B cells - Memory B cells - Plasma cells - Plasma cells, T cells, and memory B cell

Plasma cells and memory B cells

What protozoa causes Malaria?

Plasmodium (nonmotile in mature form)

Why are smokers more likely to have infections with respiratory pathogens? - Smokers do not produce lysozyme in their mucus. - Respiratory pathogens produce substances that react with tobacco smoke. - Poisons and tars in tobacco smoke damage ciliated columnar cells. - Smokers do not produce as much mucus as do nonsmokers.

Poisons and tars in tobacco smoke damage ciliated columnar cells. - Tobacco smoke contains substances that damage ciliated cells in the respiratory tract. This makes it more difficult for smokers to clear their lungs of potential pathogens.

Methods to recognize mutants

Positive selection Negative (indirect) selection Ames test

How does the number of infectious prions increase? - Prions reproduce by mitosis. - Prions reproduce by binary fission. - Prions transform normal proteins into the misfolded beta-pleated sheet configuration; therefore, prions multiply by conversion. - Prions form multimers which can then form more single copies of the prion protein.

Prions transform normal proteins into the misfolded beta-pleated sheet configuration; therefore, prions multiply by conversion.

A bacterium is Gram-positive, mesophilic, and facultatively halophilic and can grow with or without oxygen. What color are the Gram-stained cells? What does the term "facultatively halophilic" mean? Describe the cell's oxygen requirement.

Purple. Can tolerate high osmotic pressure; can colonize our skin. Facultative anaerobe.

* Cells Transcribe 6 Main Types of RNA from DNA

RNA Primer - molecules for DNA polymerase to use during DNA replication Messenger RNA - molecules which carry genetic information from chromosomes to ribosomes Ribosomal RNA - molecules which combine with ribosomal polypeptides to form ribosomes (the organelles that synthesize polypeptides) Transfer RNA - molecules which deliver the correct amino acids to ribosomes based on the sequence of nucleotides in mRNA Regulatory RNA - molecules which interact with DNA to control gene expression Ribozymes - RNA molecules that function as metabolic enzymes in a cell

According to the animation, which of the following makes mRNA from the information stored in a DNA template? - RNA polymerase - Ribosomes - DNA polymerase - tRNA

RNA polymerase

The repressor of the lac operon binds to DNA and prevents the ____ from binding to the promoter.

RNA polymerase

When the cell is NOT in the presence of tryptophan, - RNA polymerase can transcribe mRNA. - structural genes are not transcribed. - the repressor proteins bind to the operator. - the repressor proteins are active

RNA polymerase can transcribe mRNA

2 Major Categories of Mutagens

Radiation Mutagens Chemical Mutagens

Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells? - Secretion of granzyme - Recognition of infected host cell using its TCR - Recognition of infected host cell using its CD4 glycoprotein - Secretion of perforin

Recognition of infected host cell using its CD4 glycoprotein - The cytotoxic T cell uses its CD8 glycoprotein to bind to the MHC-I of an infected host cell.

Location used for Replication, Transcription, Translation

Rep - Prok: cytosol - Euk: nucleus Transcription - Prok: cytosol; can be simultaneous with transl - Euk: nucleolus within nucleus Translation - Prok: cytosol; can be simulatenous with transc - Euk: cytosol or on RER

Direction of Polymerization used for Replication, Transcription, Translation

Rep - 5 ' to 3 ' Transc - 5 ' to 3 ' Transl - N terminus (end w/ amino group) to C terminus (end w/ carboxyl group)

Enzymes used for Replication, Transcription, Translation

Rep - DNA polymerase Transcription - RNA polymerase Translation - Ribosomes

Start Site used for Replication, Transcription, Translation

Rep - Origin of replication Transc - Promoter Transl - AUG start codon

Fidelity Mechanism used for Replication, Transcription, Translation

Rep - Polymerase proofreading, followed by mismatch repair systems Transc - none Transl - Specificity of enzymes that charge tRNAs

Termination used for Replication, Transcription, Translation

Rep - Termination resquences Transc - Terminator Transl - UAA, UAG, UGA stop codons

Templates used for Replication, Transcription, Translation

Rep - both parent DNA strands Transcription - one DNA strand Translation - mRNA

Energy Source used for Replication, Transcription, Translation

Rep - deoxyribonucleotides Transc - ribonucleotides Transl - ATP for charging tRNAs

Product of Replication, Transcription, Translation

Rep - two daughter DNA strands, each paired w/ one original strand (semiconservative) Transc - RNA single strand Transl - polypeptides; some function alone as proteins, some work together as a single protein

Which step of binary fission is the reason for genetically identical daughter cells? - Elongation of the cell - Replication of the bacterial chromosome - There are four new daughter cells that result from one parental cell - Splitting of the two daughter cells

Replication of the bacterial chromosome

Which of the following is a molecule involved in transcription termination in prokaryotic cells? - a release factor - a sigma factor - the Rho protein - an anticodon

Rho protein

Which of the following regulatory RNAs is NOT correctly described? - MicroRNAs bind to messenger RNA to silence the message. - Ribosomal RNA may inhibit translation by binding up GTP and destabilizing the A site. - Small interfering RNAs are small and double stranded and may induce degradation of target RNA. - Riboswitches change conformation in response to environmental changes.

Ribosomal RNA may inhibit translation by binding up GTP and destabilizing the A site.

* Physical/chemical interference has what effect on protein synthesis?

Ribozymes, RNA molecules, are made of nucleic acids. Ribozymes catalyze protein synthesis in ribosomes. If nucleic acids are alter/damaged by physical/chemical agents, then protein synthesis is stopped!

Which finding is most surprising from Griffith's experiments? - S strains are able to escape phagocytosis. - S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains. - R strain cells fail to produce a capsule. - S strain cells kill the mice.

S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains.

How can scientists know the normal prevalence of a given disease?

Scientists record every case of the disease so that they will have a "baseline" prevalence, which then becomes the expected prevalence for each disease.

Is the Primary or Secondary response stronger?

Secondary! - memory T cell outnumber the original T cells during the initial exposure - a subsequent cell-mediated immune response to a previously encountered antigen is much more effective than a primary response - this is called "Memory Response"

Because some target bacterial species are out-competed by others during growth on media, it is sometimes necessary to inhibit the growth of the competitors. What type of medium is specialized for this scenario?

Selective media inhibit the growth of competitors while facilitating the growth of bacteria of interest.

What is likely is worst infectious disease of all time? (2)

Smallpox - 33% death rate

Soaps and Detergents - Surfactants (4)

Soaps: - degerming (NOT antimicrobial) - Removes vegetative bacteria, endospores, cysts, and viruses from hands - Soaps have hydrophilic and hydrophobic ends Detergents: - antiseptic - positively charged organic surfactants

Why would a particular microbe need to be cultured inside an animal? - The microbe can grow slower inside an animal. - Standard laboratory culture techniques have proven inadequate. - The microbe becomes more pathogenic when grown inside a live animal host. - It allows researchers to simultaneously observe the pathogenic effects of the microbe.

Standard laboratory culture techniques have proven inadequate.

Review - What is the function of stem cells within the respiratory epithelium?

Stem cells in the respiratory epithelium undergo cytokinesis to form both ciliated cells and goblet cells to replace those lost during normal shedding.

Lipid Catabolism (10)

Step 1. Hydrolysis - hydrolysis separates glycerol from fatty acid chains - uses lipase and water - Glycerol is converted to glyceraldehyde 3-phosphate and enters energy-conserving stage Step 2. Beta-oxidation - it breaks down fatty acid chains - CoA binds to the end of fatty acid chain - Carbon pair is cleaved; produces 1 FADH2 & 1 NADH - Acetyl-CoA enters Kreb's - FADH2 and NADH enter ETC

Protein Catabolism

Step 1. Protease activity - proteins are too large to cross membrane - proteases are secreted to breakdown protein extracellularly - individual amino acids small enough to enter cell Step 2. Deamination - Amine group (NH2) is removed - Product converted and enters Krebs cycle

The goal of streaking for isolation is to spread an inoculum of bacteria thinner and thinner with each pass for the identification of individual colony-forming units. What action must be performed between each step to ensure this? - Sterilization of the loop must be performed. - Sterilization of the agar plate must be performed. - The agar plate must be incubated overnight. - An additional inoculum of bacteria must be added.

Sterilization of the loop will destroy all remaining bacteria, ensuring that the next pass will spread fewer bacteria

2 common isolation techniques

Streak plates - mechanically (w/ inoculation loop) dilutes sample to separates CFUs Pour plates - separates CFUs through a series of dilutions; only works well w/ a large # of CFUs in the initial sample —> w/ this method, colonies form both at and below the surface of the medium

What is the purpose of using the streak plate method? - The streak plate method will prevent any contamination of a culture. - The streak plate method is a way of sterilizing media. - Streak plates lead a scientist toward a pure culture for identification or examination of a single bacterial strain. - A streak plate allows the scientist to study many microbes on one medium.

Streak plates lead a scientist toward a pure culture for identification or examination of a single bacterial strain.

What bacteria makes a biofilm that causes dental plaque?

Streptococcus mutans

Symptoms

Subjective characteristics of disease felt only by the patient

Syndrome

Symptoms and signs that collectively characterize a disease or abnormal condition

The leading strand in DNA replication is characterized by all EXCEPT which of the following features? - Synthesis moves away from the replication fork. - DNA polymerase starts at the origin and follows helicase. - The leading strand requires one RNA primer. - Synthesis is continuous and moves in the 5′ to 3′ direction.

Synthesis moves away from the replication fork. (leading - moves towards) (lagging - moves away)

In the thymus, T cells randomly generate different __________ with a particular shape - MHC proteins - epitopes - T cell receptors - cytotoxins

T cell receptors - In the thymus, each T cell generates a different T cell receptor resulting in a great variety of T cells, each specific for recognizing a different antigen.

Which of the following defense systems would be involved in eliminating virally-infected cells? - Complement system - T lymphocytes - Humoral immunity - Phagocytosis

T lymphocytes

Which of the following statements about T lymphocytes is FALSE? - T lymphocytes have TCRs that recognize antigen only if it is bound to MHC. - T lymphocytes produce antibody molecules. - There are three types of T lymphocytes. - T lymphocytes directly attack cells and produce the cell-mediated immune response. - T lymphocytes are called such because they mature in the thymus.

T lymphocytes produce antibody molecules

How do lymphocytes develop receptors complementary to normal body components (autoantigens)?

T lymphocytes randomly generate the variable region shapes of their TCRs - It is vitally important that adaptive immune responses not be directed against autoantigens - When self-tolerance is impaired, the result is an autoimmune disease

An antigen that is potent enough to activate a B cell on its own is known as: - BCR. - T-independent antigens. - T-dependent antigens. - antibodies.

T-independent antigens.

Review - Name an antimicrobial protein found in tears

Tears contain lysozyme, an antimicrobial protein which acts against the peptidoglycan of bacterial cell walls.

Antimicrobial Agents that Inhibit Protein Synthesis (4)

Tetracycline - Aminoglycosides block docking site of tRNA Chloramphenicol - blocks peptide bond formation Erythromycin - lincosamides or macrolides bind to 50S unit, blocking proper mRNA movement; synthesis stops Streptomycin - Aminoglycosides change 30S shape so mRNA is misread

Example of a Broad-Spectrum Drug

Tetracycline - effective against Gram-positive, Gram-negative, chlamydias, and rickettsias

+ssRNA viruses of animals

The -ssRNA is transcribed by viral RNA-dependent RNA polymerase for genome of new virions - Positive-sense ssRNA virus, in which +ssRNA acts as mRNA and −ssRNA is synthesized for a viral genome template.

How is the HIV provirus different from a lambda-phage prophage? - Lambda phage-infected cells produce virus slowly over time. - All subsequent generations of HIV-infected cells carry the provirus. - The HIV provirus is inactive inside the host cell. - The HIV provirus is integrated permanently into the host cell's DNA. - All the offspring of a cell infected with a prophage will contain the virus.

The HIV provirus is integrated permanently into the host cell's DNA.

What most likely explains the recovery of live S strain cells from a mouse injected with heat-killed S strain mixed with live R strain cells? - The S strain fused with the R strain, making it resistant. - The S strain was revived by the presence of the host's immune system. - The R strain cells picked up the capsules from the S strain cells. - The R strain picked up the S strain DNA, enabling it to produce a capsule.

The R strain picked up the S strain DNA, enabling it to produce a capsule.

Quorum sensing (4)

The ability of bacteria to sense population density via secreted chemical signals (autoinducers; quorum-sensing molecules) - once binding exceeds a threshold limit, cells activate previously suppressed genes - enzyme production, changed cell shape, formation of mating types, and the ability to form and maintain biofilms can change - up to 10% of a cell's genes can be regulated by quorum sensing

How does the ribosome know if the entering charged tRNA is correct? - The incorrect tRNA does not fit into the A site. - The anticodon on the tRNA base pairs to the codon on the mRNA. - The preceding amino acid will not permit it to enter the A site.

The anticodon on the tRNA base pairs to the codon on the mRNA.

What happens if a cell wall is disrupted by chemical/physical agents when the cell is in a hypotonic solution?

The cell wall no longer prevents the cell from bursting as water moves into the cell by osmosis

What characteristic of the S strain allows it to evade the immune system of the mice? - They are naturally competent. - The cells have a capsule. - They are genetically engineered to be resistant to killing. - They are resistant to heat.

The cells have a capsule. (S strain = smooth, encapsulated)

Fluid Mosaic Model

The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.

Which statement about DNA replication is CORRECT? - The lagging strand is built continuously. - The leading strand is one of the strands of parental DNA. - DNA ligase helps assemble the leading strand. - The leading strand is built continuously, and the lagging strand is built in pieces. - The lagging strand is one of the strands of parental DNA.

The leading strand is built continuously, and the lagging strand is built in pieces.

If a microbe were capable of preventing a phagosome from fusing with a lysosome, which of the following would occur? - The microbe would cause the phagocyte to go through apoptosis. - The microbe would be expelled from the residual body. - The microbe would be killed by the lysosome's enzymes. - The microbe would survive inside the phagocyte.

The microbe would survive inside the phagocyte

If microorganisms can survive at temperatures lower than their minimum growth temp, then why is it called "minimum"?

The min. growth temp is defined as the lowest temp that supports metabolism. Though organisms might survive at lower temps, they don't actively metabolize, grow, or reproduce

Why are the beta-pleated multimers of PrP potentially pathogenic? - They are found on the surface of immune cells, resulting in damage to the immune system. - They are not detected by other organisms. - They repress the immune system. - The multimers are more stable and resistant to protease.

The multimers are more stable and resistant to protease.

* Template Strand

The nucleotide sequence of the template strand determines the nucleotide sequence of the mRNA strand.

"The microorganisms grow in salt-containing media." What is this understood to mean?

The organisms metabolize and reproduce rather than they increase is size.

Which organelle is responsible for the degradation of exogenous antigen within an antigen-presenting cell? - Ribosome - Nucleus - Endoplasmic reticulum - Phagolysosome

The phagolysosome is the site of exogenous antigen degradation within an antigen-presenting cell.

Describe one method of genetic recombination (4 steps)

There are 2 DNA molecules, each with homologous sequences. 1. enzymes nick one strand of DNA at the homologous sequence 2. another enzyme inserts the nicked strand into the second DNA molecule 3. Ligase reconnects the strands in new combinations 4. Molecules resolve themselves into novel molecules

What is apoptosis? - The process of programmed cell death. - The receptor on a cytotoxic T-cell that recognizes MHC molecules. - A protein molecule that forms a pore in the membranes of infected cells. - The proliferation of cytotoxic T-cells.

The process of programmed cell death.

Which of the following best characterizes clonal selection? - The production of identical B cells producing the same antibody - The production of identical T cells producing the same antibody - The production of identical B cells producing different antibodies - The production of different antigens by the same B cell

The production of identical B cells producing the same antibody

According to the animation, to what genetic element does the RNA polymerase bind? - The promoter - The repressor protein - The operator - The repressor mRNA

The promoter

Peripheral Proteins

The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane.

Would it take longer to sterilize 1 L of fluid in a flask or 1 L of fluid distributed into smaller tubes?

The single 1 L flask would take longer. - Sterilizing large volumes of liquids or solids slows the process because they require more time for heat to penetrate.

A cell is placed in a hypotonic solution. Describe the osmotic pressure and resulting water flow.

The solution has a lower osmotic pressure (hypotonic; less solute) than the cell. Water will rush into the cell.

A cell is placed in a solution with a higher osmotic pressure than itself. What does that mean?

The solution is hypertonic (greater osmotic pressure) to the cell. The cell will lose water to the solution through osmosis.

Which of the following genetic elements is transcribed into a single mRNA? - The repressor - The structural genes - The promoter - The operator - The inducer

The structural genes

In reference to clonal deletion, what are the clones? - They are the offspring or potential offspring of lymphocytes. - They are the stem cells from which all T cells are derived. - They are the cells of the thymus. - They are the T cells that undergo apoptosis.

They are the offspring or potential offspring of lymphocytes. - The clones are exact copies of lymphocytes that have been activated against a specific antigen and stimulated to divide into a large population of cells (clones).

How does the mismatch repair system determine which of the two strands is in error?

They distinguish a new DNA strand from an old strand because old strands are methylated. Recognition of an error as far as 1000 bp away from a methylated portion of DNA triggers mismatch repair enzymes. (Once a new DNA strand is methylated, mismatch repair enzymes cannot correct any errors that remain, so mismatch repair must immediately follow DNA replication.)

Most metabolic pathways are amphibolic. What does this mean?

They function as part of either catabolism or anabolism as needed.

Which of the following is NOT a way in which viruses differ from all other living things? - They live inside host cells. - They do not grow. - They cannot self-replicate. - They cannot respond to environmental stimuli through metabolic changes

They live inside host cells - Other organisms, including some bacteria and protozoans, live inside the cells of their hosts.

Why can't rubber, paper, or most plastic objects be sterilized in an oven?

They oxidize rapidly (combust) in temperatures of 171°C for 1 hour or 160°C for 2 hours

What is the fate of activated cytotoxic T-cells? - They can mature and attack infected cells. - Each activated cytotoxic T-cell proliferates, forming a clone of cells specific to the same antigen. - They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells. - They can differentiate into long-lived memory T-cells. - They are destroyed via apoptosis. - They are infected by viruses.

They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells.

How are viruses grouped?

They're grouped based on how mRNA is synthesized

How are most prokaryotes known? (3)

They're known only from their ribosomal "fingerprints" - known only from sequences of rRNA that don't match any known rRNA sequences - scientists now classify prokaryotes on the relative similarities of their rRNA sequences

Which of the following statements best describes translation of the genetic code into peptides in a cell? - Transfer RNA delivers amino acid as directed by messenger RNA. - Three types of RNA (mRNA, tRNA, and rRNA) in the ribosome synthesize peptides based on nucleotide sequences. - Messenger RNA carries information from chromosomes as triplet sequences. - Ribosomal RNA catalyzes the peptide bond between amino acids in the A and P sites of a ribosome.

Three types of RNA (mRNA, tRNA, and rRNA) in the ribosome synthesize peptides based on nucleotide sequences.

Reduction of Microbial Antagonism Example

Thus, a woman using erythromycin to treat strep throat (a bacterial disease) could develop vaginitis resulting from the excessive growth of Candida albicans (kan'did-ă al'bi-kanz), a yeast that is unaffected by erythromycin and is freed from microbial antagonism when the antibiotic kills normal bacteria in the vagina.

In general, what types of cells are involved in tissue repair? (picture)

Tissue repair is effected by cells that are capable of cytokinesis and differentiation. If fibroblasts are among them, scar tissue is laid down.

What is the basic function of the lac operon? - To code for enzymes involved in synthesizing lactose. - To code for enzymes involved in catabolizing lactose. - To produce lactose when none is present - To produce glucose when none is available

To code for enzymes involved in catabolizing lactose.

What is the overall function of the trp operon? - To block RNA polymerase from the structural genes - To always make sure the operator is being bound to repressor proteins - To control the production of repressor proteins - To ensure that the cell has a supply of tryptophan at all times

To ensure that the cell has a supply of tryptophan at all times

Tom has a genetic disorder in which he does not synthesize class I MHC proteins or functional NK cells. Which of the following statements would be true for Tom? - Tom would not be able to produce antibodies against viruses. - Tom would not be able to destroy virally-infected cells. - Tom would be more susceptible to bacterial infections. - Tom would be less susceptible to helminth infections

Tom would not be able to destroy virally-infected cells.

Routes of Administration

Topical - application of drug for external infections Oral - requires no needles and is self-administered Intramuscular - administration delivers drug via needle into muscle Intravenous - administration delivers drug directly to bloodstream - can be administered one-time or continuous

What is unique about transduction compared to normal bacteriophage infection? - The bacteriophage takes fragments of the cell with it during transduction. - The bacteriophage does not erupt from an infected cell during transduction. - Transduction transfers DNA from the chromosome of one cell to another

Transduction transfers DNA from the chromosome of one cell to another

Why might a hospital choose to use transport media to carry clinical specimens? - Transport media enable the transporter to easily add more nutrients during transit. - Transport media allow for long-term storage of microorganisms. - Transport media are designed to keep microorganisms growing during transport. - Transport media are designed to keep microbes stable until they can be inoculated into appropriate growth media.

Transport media are designed to keep microbes stable until they can be inoculated into appropriate growth media. - provides an environment that is not hostile to the survival of certain microbes.

Which of the following statements concerning transposons is FALSE? - A special enzyme is needed for the insertion of some transposons. - Transposons are found only in prokaryotic cells. - Transposons are often called "jumping genes." - All transposons contain palindromic sequences at their ends.

Transposons are found only in prokaryotic cells.

Which of the following amino acids is coded by only one codon? - Tyr - Glu - Phe - His - Trp

Trp

Positive selection involves eliminating wild-type phenotypes and favoring mutant phenotypes with media. T/F

True

Slow freezing is more damaging to microbial cells than quick freezing. T/F

True

Archaea can have fimbriae. T/F

True; many do! Archaea DO NOT HAVE pili and their fimbriae aren't used much for movement

Why is the tryptophan operon turned off in the presence of tryptophan? - Tryptophan binds to and activates the repressor proteins; the repressor proteins, in turn, bind to the operator, preventing transcription. - Tryptophan can be used over and over again in the cell. - Tryptophan is not an important amino acid for cells.

Tryptophan binds to and activates the repressor proteins; the repressor proteins, in turn, bind to the operator, preventing transcription.

List the 3 STOP codons

UAA, UAG, UGA - instruct ribosomes to stop translating - UGA can code for selenocysteine

Which form of nonionizing radiation has sufficient energy to be practical antimicrobial agent?

UV light

What factor may induce a prophage to enter the lytic cycle? - replication of the host bacterium - UV light - Infection by an additional phage - burst time

UV light - Ultraviolet radiation is known to cause the induction of prophage into the lytic cycle.

How is translation terminated? - When the ribosome runs out of the mRNA - When there are no more charged tRNA molecules - When a protein called a release factor enters and binds to the A site - When the A, P, and E sites are all filled

When a protein called a release factor enters and binds to the A site

Viral mRNA Translation produces: (4)

Viral proteins! - capsomeres - components of the tail - viral DNA polymerase - lysozyme (weakens cell wall from within to release virions)

** Viruses cause what percentage of human cancers?

Viruses cause 20-25% of all human cancers

Size of Viruses - differences in viruses How can viruses be so small and yet still be pathogenic?

Viruses utilize a host cell's enzymes, organelles, and membranes to complete their replication cycle.

When is denaturation considered permanent? (2)

When an enzyme cannot regain its original structure once conditions return to normal ex. the irreversible solidification of albumin in cooked egg whites

Autoclave vs. Oven Example

Whereas an autoclave needs about 15 minutes to sterilize an object at 121°C, an oven at the same temperature requires at least 16 hours to achieve sterility.

Riboswitch example (4)

Yersinia pestis - mRNA for the virulence regulator of the plague bacterium folds to prevent translation when temp. is below 37 C - when bacterium enters a human, the mRNA refolds into a shape that allows translation - virulence regulator is synthesized & plague ensues

Is it important to consider how the blood distributes antimicrobial agents to infected tissue? (2)

Yes! - an agent quickly removed by blood could be a good choice for a bladder infection but not a heart infection - infection of the brain, spinal cord, and eye are difficult to treat. Their BVs are almost impenetrable to antimicrobials due to the blood-brain barrier

The peptidoglycan cell wall of bacteria is most analogous to ___. - a sugary candy shell - a chain-link fence - a rain coat - an impenetrable brick wall

a chain-link fence (the peptidoglycan cell wall is mesh-like, allowing for easy passage of ions, amino acids and nutrients while maintaining structural integrity)

Anaerobic respiration

a molecule other than oxygen serves as the final electron acceptor

Inherited Prion Disease

a mutation in the cellular PrP gene results in the initial formation of prion PrP

asexual budding in yeasts

a process in which a daughter cell grows off the mother cell

Antibody

a protective protein secreted by descendants of a B cell that recognizes and strongly binds to the specific biochemical shape of the antigen

Contact between a phage and its bacterial host occurs by _____. - using phage tail fibers - a random collision - using jet-style propulsion - using flagella

a random collision - Phages are incapable of movement, and thus are completely reliant on randomly colliding with a bacterium before attachment.

Review - what is a plasmid?

a small, circular, extrachromosomal molecule of DNA

Conjugation

a unidirectional method of horizontal gene transfer from a donor to a recipient

What do organisms use to meet energy needs and to build organic molecules and cellular structures?

a variety of nutrients from a variety of sources!

bacteriophage (phage)

a virus that infects bacteria

Immune privilege

able to tolerate antigens and not mount an immune response (inflammation) - eyes - testicles - placenta and fetus - small extent, brain

SPECIFIC VIRUSES are known to cause what percentage of human cancers? (5)

about 15% - Burkitt's lymphoma: Epstein-barrvirus (HHV-4) - Hodgkin's disease: Epstein-barrvirus - Kaposi's sarcoma: HIV - Cervical cancer: HPV

A pH below 7 is ___

acidic

fragment C3b

acts as an opsonin

DNA polymerase III proceeds at what rate?

adds about 500-1000 nucleotides per second

A + T (3)

adenine + thymine - formed by 2 Hydrogen bonds - found ONLY in DNA

A + U (3)

adenine + uracil - formed by 2 Hydrogen bonds - found in RNA only

Ligands are called ___ on bacteria and called ___ on viruses.

adhesins on bacteria attachment proteins on viruses

In regard to antibody function, identify the MISMATCHED pair - opsonization = simulates phagocytosis - neutralization = covering a critical portion of a toxin so that it is no longer harmful - antibody-dependent cell-mediated cytotoxicity = target cell dies by apoptosis - agglutination = antibodies bind microbes to the vessel walls inhibiting spread of the microbe

agglutination = antibodies bind microbes to the vessel walls inhibiting spread of the microbe - Agglutination causes soluble molecules to become insoluble, which may target them for phagocytosis or filtering by the kidneys

Plasma Proteins

albumins, globulins, fibrinogen - inflammation, blood clotting, etc.

Which of the following is NOT an example of a fungus? - molds - yeasts - mushrooms - algae

algae

In archaea and bacteria are prokaryotes, what are the eukaryotes?

algae, protozoa, fungi, animals, and plants (SEPARATE FROM THE 6 CATEGORIES OF MICROORGANISMS!)

** Which stages of bacterial translation require additional protein factors?

all 3 stages

What is another way that All cells gain nitrogen?

all cells recycle nitrogen from their amino acids and nucleotides

C3a and C5a

also trigger the release of other inflammatory chemicals

Which of the following are phagocytic cells descended from monocytes? - alveolar macrophages - dendritic cells - microglial cells - alveolar macrophages and dendritic cells - alveolar macrophages and microglial cells

alveolar macrophages and microglial cells

Peptidoglycans are composed of sugars and ___. - amino acids - nucleic acids - lipids - teichoic acids

amino acids (combine to form the peptide portion of peptidoglycan)

* Review - What does tRNA transfer to a ribosome during translation?

an amino acid - the anticodon is what binds to the mRNA

Selective Toxicity

an effective antimicrobial agent must be more toxic to a pathogen than to the pathogen's host

Pandemic - Occurrence of Disease

an epidemic disease occurring on more than one continent at a given time

Which of the following functions might be associated with genes carried on a bacterial plasmid? - metabolism - antibiotic resistance - cellular reproduction - growth

antibiotic resistance

How does the body protect itself from exotoxins?

antibodies! - bind to specific toxins and neutralize them

Synthetic Drugs

antimicrobials completely synthesized in a lab

Which of the following is/are involved in the regulation of translation in cells? - ethidium bromide - operators - exons - antisense RNA

antisense RNA what is this???

An antimicrobial chemical used on the skin is usually called __________. - a sterilant - an antiseptic - a germicide - a disinfectant

antiseptic - Antiseptics often contain the same chemicals as disinfectants, but they are less concentrated and therefore safer to use on living tissues.

Which of the following is a prokaryote? - protozoa - archaea - algae - fungus - both archaea and protozoa

archaea (and bacteria!)

Which of the following are prokaryotes? - archaea - worms - protozoa - algae - molds

archaea (and bacteria) (prokaryotes lack nuclei in their cells)

The leukocytes called natural killer lymphocytes: - are nonspecific leukocytes that secrete toxins onto the surface of virus-infected cells. - are specialists in killing bacteria. - release prostaglandins and leukotrienes in response to microbes. - increase in allergies and helminth infection. - respond to the coating of a pathogen by complement.

are nonspecific leukocytes that secrete toxins onto the surface of virus-infected cells

Vectors

arthropods that transmit diseases

A physician wants to stimulate immunological memory in a patient. Which of the following types of immunity would be the most useful? - artificially acquired passive immunity - naturally acquired passive immunity - artificially acquired active immunity - naturally acquired active immunity

artificially acquired active immunity

How do all prokaryotes reproduce?

asexually (none produce sexually) - the common way is Binary Fission

type 1 helper T cells (Th1 cells)

assist cytotoxic T cells and stimulate and regulate innate immunity

The normal function of the PrP protein in mammals is believed to be: - assisting in normal synaptic development and function. - assisting proteins in forming beta-pleated sheets. - assisting in normal membrane development and function. - assisting proteins in forming alpha-helices.

assisting in normal synaptic development and function.

Lithotrophs

autotrophic organelles acquire electrons or hydrogen atoms from inorganic molecules

Why wouldn't a drug like Terbinafine be effective against bacteria?

bacteria lack sterols, which is the element of the cytoplasmic membrane that allylamines act upon (ergosterol)

just review- 6 categories of microorganisms

bacteria, archaea, fungi, protozoa, algae, small multicellular animals (helminths) (parasitic worms)

Review - Requirement for Transduction

bacteriophage

How are algae categorized? (3)

based on pigmentation, storage products & composition of cell wall

3 Types of T Cells

based on surface glycoproteins and characteristic functions - Cytotoxic T lymphocyte, TC(CD8 cell) - Helper T lymphocyte, TH(CD4 cell) - Regulatory T lymphocyte, TReg

Why were prion diseases thought to be caused by "slow viruses"?

because 60 years might lapse between an infection and the onset of signs and symptoms

Why is boiling not recommended when true sterilization is required?

because bacterial endospores can withstand boiling for more than 20 hours!

Prokaryotic ribosomes can begin translation before transcription is finished. How?

because both events occur in the cytosol of prokaryotes (no nucleus to wait on!)

Why are organisms sensitive to changes in acidity?

because hydrogen ions interfere with hydrogen bonds within proteins and nucleic acids - H+ and OH- interfere with hydrogen bonding

* Does phenotype determine genotype? Why?

because not all genes are active at all times

Why are prions NOT viruses?

because prions lack nucleic acid

Antibacterial drugs constitute the greatest number and diversity of antimicrobial agents. Why?

because there are many differences between the structure and metabolism of pathogenic bacteria and their eukaryotic hosts

How is Decimal Reduction Time used in the food industry? (4)

because they must heat foods to eliminate the endospores of anaerobic Clostridium botulinum, which could germinate and produce life-threatening botulism toxin inside sealed cans - apply heat in a 12-fold reduction, which leaves only a very small chance that any particular can of food contains a single endospore - D value for C. botulinum endospores at 121°C is 0.204 minute - D value for C. botulinum endospores at 121°C is 0.204 minute

How do most unicellular microorganisms reproduce? (4)

binary fission - a cell grows to twice its normal size and divides in half to produce two daughter cells of equal size - four steps - results in logarithmic growth

What are the largest of cells?

bird eggs

May components of the 2nd line of defense either are contained in or originate in the ___.

blood (complex liquid tissue composed of cells and portions of cells within plasma)

hematopoiesis (picture)

blood stem cells located principally in the bone marrow within the hollow cavities of larger bones produce three types of formed elements

Which of the following bacterial genera produce(s) endospores? - Lactobacillus - Clostridium - Bacillus - both Bacillus and Lactobacillus - both Bacillus and Clostridium

both Bacillus and Clostridium

Which of the following bacterial structures plays an important role in the creation of biofilms? - fimbriae - pili - flagella - glycocalyces - both fimbriae and glycocalyces

both fimbriae and glycocalyces

Which of the following may be a component of bacterial cell walls? - tubulin - carrageenan - lipoteichoic acids - mycolic acids - both lipoteichoic and mycolic acids

both lipoteichoic and mycolic acids

The outermost layer of a virion fulfills which of the following functions of the virus? - recognition - protection - replication - both protection and recognition - both recognition and replication

both protection and recognition

Which of the following is NOT a typical habitat for an extremophile? - deep-sea hydrothermal vents - the bottom of a swamp - acidic hot springs - the Dead Sea

bottom of a swamp - Extremophiles can be thermophiles or halophiles, both of which can survive in extreme environments. Methanogens are more likely to be found at the bottom of a swamp.

The process known as ________ is a mechanism of release for enveloped viruses. - lytic replication - latency - persistent infection - metastasis - budding

budding

In which of the following methods of prokaryotic reproduction does the parental cell exist before AND after the reproduction event? - binary fission and snapping division - snapping division - budding - binary fission

budding - In the process of budding, small buds receive copies of the cell's genetic material and break off, becoming independent cells. The parental cell is preserved during the process.

How do scientists distinguish wild-type cells from mutants?

by observing or testing for altered phenotypes

commercial sterilization example

commercial sterilization of canned food does not kill all hyperthermophilic microbes; because they do not cause disease and cannot grow and spoil food at ambient temperatures, they are of no practical concern

Competent cells are cells that: - have the ability to produce capsules. are killed by heat. - are also considered "rough-strain" based on colony phenotype. - can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.

can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.

Which of the following is NOT a characteristic of a eukaryotic cell? - contain chromosomes composed of DNA and histones - can undergo transcription and translation simultaneously - presence of membrane-bound organelles - presence of a nuclear envelope

can undergo transcription and translation simultaneously

What are malignant tumors called?

cancers

Some bacteria have an outer layer called a ___ which allows them to adhere to surfaces and contributes to their ability to cause disease. - flagellum - capsule - cell wall - pilus - LPS

capsule

Some bacteria have a water-soluble outer slime layer composed of: - lipid - peptidoglycan - carbohydrate - protein - lipoteichoic acid

carbohydrate

What is commonly oxidized as the primary energy source for anabolic reactions? (2)

carbohydrates * Glucose is the most common carb used

What are the most common nutrients?

compounds containing necessary elements such as Carbon, Oxygen, Hydrogen and Nitrogen (remember C.O.H.N.)

The energy required for DNA polymerization (the addition of nucleotides to a DNA strand) is carried by what?

carried by each triphosphate nucleotide in the high-energy bonds between phosphate groups ex. Guanine base + deoxyribose sugar = Guanosine (nucleoside) Guanosine (nucleoside) + one phosphate group = Guanine nucleotide (dGMP) Guanine nucleotide + 2 phosphate groups (diphosphate) = Guanosine triphosphate deoxyribonucleotide (dGTP) When a triphosphate nucleotide (like dGTP) is polymerized (attached to existing strand), the diphosphate molecule is removed! That energy is released and used for that synthesis. A longer DNA strand is produced.

Hydrogen peroxide does NOT make a good antiseptic for open wounds because __________. - it evaporates too quickly - catalase in human tissues neutralizes it - it is too toxic for human cells - it is too expensive for this type of use

catalase in human tissues neutralizes it

Exogenous HAIs

caused by pathogens acquired from the health care environment

Review - Requirement for Conjugation

cell-to-cell contact and F plasmid, which is either in cytosol or incorporated into chromosome of donor (Hfr) cell

A chemical agent that dissolves lipids can damage: - cells. - nonenveloped and enveloped viruses. - bacterial endospores. - enveloped viruses. - cells and enveloped viruses.

cells and enveloped viruses.

asexual spores

cells that produce a new individual without fusing with another cell

Conjugation

cells use pili to transfer DNA from one cell to the other

carcinogenic

chemical capable of causing cancer

chemotactic factors

chemicals that recruit leukocytes to a site

fragment C5a

chemotactic, attracting phagocytes to the site of infection

Both pathways converge on C3 (3)

cleaves into C3a and C3b - C3a: inflammation - C3b: opsonizationand membrane attack complex

The ability of a specific immune cell to proliferate and form many generations of nearly identical cells is called __________. - specificity - memory - clonality - inducibility

clonality - Specific immune cells such as B cells make a huge impact on the immune response, in part because of their ability to rapidly clone themselves, a characteristic called clonality.

Sarcinae

cocci that divide in three planes to form cuboidal packets

Diplococci

cocci that remain attached in pairs

Triplet nucleotides of mRNA that code for specific amino acids are ___

codons

Collecting from lungs

collect sputum either dislodged by coughing or acquired via a catheter

microbial growth forms either a __ or a ___.

colony - aggregation of cells arising from a single parent cell biofilm - a collection of microbes living on a surface in a complex community

A transducing phage: - cannot infect new host cells. - contains fragments of the host chromosome instead of the viral genome. - has a viral coat made of host proteins. - is a lysogenic bacteriophage.

contains fragments of the host chromosome instead of the viral genome.

Ionizing radiation can energize electrons that may break ____ bonds in DNA, causing mutations.

covalent

Colonies (2)

cultures visible on the surface of solid media - bacterial and fungal colonies often have distinctive characteristics

Which type of cell directly attacks infected cells? - Cancerous cells - Helper T-cells - Cytotoxic T-cells - Bacterial cells

cytotoxic t cells

3 Approaches to Epidemiology

descriptive, analytical, and experimental epidemiology

What is the difference between dGTP and rGTP?

dGTP contains deoxyribose sugar (DNA) rGTP contains ribose sugar (RNA)

Why is using antimicrobial drugs to kill large numbers of Gram-negative bacteria in a short period of time a cause for medical concern? - dead Gram-negative cells release lipid A, which causes fever and other medical problems - Gram-negative bacteria often contain viruses that are released when they die - dead Gram-negative bacteria are more infectious than live Gram-negative bacteria - dead Gram-negative cells transform into Gram-positive cells, which release exotoxins

dead Gram-negative cells release lipid A, which causes fever and other medical problems

A nurse preparing a section of skin for an injection is an example of __________. - sanitization - disinfection - degerming - sterilization

degerming - Even something as simple as washing your hands can be an effective degerming method.

Exogenous antigens are processed for immune recognition by ________ cells. - helper T - all nucleated - dendritic - macrophage - dendritic and macrophage

dendritic and macrophage

Genomes of cells and DNA viruses are composed of:

deoxyribonucleic acid (DNA)

Sporadic Prion Disease

develops following a rare random change of c-PrP in the membrane into p-PrP; note that this is a change in protein shape—the PrP gene remains normal in these patients

Kinase - Extracellular Enzymes of Virulence Factors

digest blood clots allowing further invasion from the bacteria that had multiplied inside

Pairs of spherical bacterial cells are called __________. - streptococci - diplococci - streptobacilli - staphylococci

diplococci

Endemic - Occurrence of Disease

disease is normally present in a region

Epidemic - Occurrence of Disease

disease is present in greater frequency than is usual

Sporadic - Occurrence of Disease

disease occurs irregularly and infrequently

Both viruses and carcinogenic chemicals can cause tumors by __________. - disruption of control over the rate of cell division - creating new cellular genes - killing cells - slowing cellular growth

disruption of control over the rate of cell division - Viruses and carcinogenic chemicals both cause tumors by interfering with the normal cellular controls over division and growth.

Antimicrobials

drugs for treating infections

* Where does transcription occur?

eukaryotes: the nucleus prokaryotes: the cytoplasm

C3am C4a, C5a

each inflammatory agents that cause localized vascular dilation, leading to inflammation

Another classification method

effects they have on populations rather than on individuals

Why are endospores used to measure the effectiveness of autoclave sterilization? - Endospores are composed of all the molecules found in living cells. - Endospores are very hard to kill. - Endospores of different bacteria are destroyed at different temperatures and can be used to calibrate autoclave temperatures. - Endospores are easy to store in the lab until needed. - Endospores are very simple structures and easy to detect.

endospores are very hard to kill

Viral Order

ends in -virales

Viral Family

ends in -viridae

Viral Genus

ends in -virus

oxidative phosphorylation

energy from redox reactions of cellular respiration is used to attach inorganic phosphate to ADP

activation energy (2)

energy that is needed to get a reaction started - enzymes lower the activation energy requirement

What removes the RNA primers? (3)

enzyme called RNAse - this leaves a gap in the DNA - DNA polymerase fills these gaps

How does the removal of water inhibit cellular metabolism?

enzymes are fully functional only in aqueous environments

Apoenzymes (3)

enzymes without their cofactors (protein enzymes not complete in themselves) - inactive if not bound to nonprotein Cofactors (inorganic) or Coenzymes (organic; all are or contain vitamins) - binding of apoenzyme and its cofactor(s) yields a Holoenzyme

Which of the following leukocytes is primarily responsible for an immune response against helminths? - basophils - natural killer cells - neutrophils - eosinophils

eosinophils

Thymus cells are specialized to participate in clonal deletion because they have the ability to __________. - express all of the body's autoantigens - undergo apoptosis - recognize MHC proteins and epitopes - express MHC proteins

express all of the body's autoantigens - Yes. Thymus cells have the ability to process all of the body's autoantigens and present them in MHC proteins.

Review - What are virions?

extracellular state - a fully formed virus that is able to establish an infection in a host cell

** What is the first amino acid for prokaryotes?

f-methionine

The majority of prokaryotes are capable of forming endospores. T/F

false

Most human pathogens can survive well outside the body. T/F

false - Most pathogens cannot survive for long outside their host - require safe haven (reservoir of infection)

The genome of an organism contains only its genes, or coding sequences. T/F

false - The genome of an organism contains all its genes or coding sequences of DNA plus the noncoding nucleotide sequences that connect genes to each other.

Archaeal cell walls are identical among taxa. T/F

false Archaeal cell walls vary among taxa and are composed of a variety of compounds, including proteins, glycoproteins, lipoproteins, and polysaccharides.

When an endospore germinates, it gives rise to two daughter cells called vegetative cells. T/F

false It produces one vegetative cell

All 5 stages occur in every disease. T/F

false!

Often, scientists will select a method to kill the weakest microorganisms first. T/F

false! - They'll often choose a method that kills the hardiest, assuming that such treatment will kill the weak too.

A rapid boil is hotter than a slow boil. T/F

false! - boiling water at normal atmospheric pressure cannot exceed boiling temperature (100°C at sea level), because escaping steam carries excess heat away

Beta-lactams, lipoglycopeptides, and bacitracin destroy existing peptidoglycan. T/F (3)

false! - these drugs prevent bacteria from increasing the amount of cell wall material but have no effect on existing peptidoglycan - they're effective ONLY on growing/reproducing cells - dormant cells are unaffected

Acellular agents cannot cause disease. T/F

false! - viruses, viroids, and prions can all cause infection

Differences in flagellar proteins have no importance to pathogen identification. T/F (2)

false! Certain pathogenic bacteria can be identified/classified by differences in their flagellar proteins.

In an autoclave, it is appropriate to wrap objects to be sterilized in plastic or aluminum foil. T/F

false! Plastic and aluminum foil are impenetrable to steam! Steam must be able to contact all contaminated liquids/surfaces. Solid objects must be wrapped in porous cloth or paper. Containers must be sealed loosely enough.

Prokaryotes are the least common group of microbes. T/F

false! Prokaryotes are by far the most numerous and diverse group of cellular microbes.

Together, the hook, rod, and rings allow the filament to rotate 90 degrees. T/F (2)

false! The filament is able to rotate 360 degrees.

Nothing can survive being frozen in -30 to -80 C. T/F

false! Vegetative bacterial cells, bacterial endospores, and viruses can survive subfreezing temps for years.

Among all prokaryotes, most are dangerous to humans. T/F

false! Very few have enzymes, toxins, or cellular structures that allow them to colonize humans or cause diseases.

Each prokaryote has a single circular chromosome. T/F (4)

false; this was thought but there are many exceptions - Epulopiscium can have hundreds or thousands of identical chromosomes - some have linear chromosomes —> Agrobacterium tumefaciens has one circular and one linear

Review - What physical methods of microbial control physically separates microbes from air/liquids?

filtration

Which of the following could be used to sterilize a heat-sensitive liquid such as urea broth? - autoclaving - lyophilization - filtration - pasteurization

filtration

Ethidium bromide is an example of which of the following? - a pyrimidine dimer - a frameshift mutagen - a nucleotide-altering chemical - a nucleotide analog

frameshift mutagen

Review - Requirement for Transformation

free DNA in the environment and a competent recipient

Aseptic means: - sanitized. - free of pathogens. - free of all microbes. - sterile. - clean.

free of pathogens

type 2 helper T cells (Th2 cells)

function in conjunction with B cells

Which of the following statements about fungi is FALSE? - fungi are photosynthetic - fungi have a cell wall - molds are multicellular - fungi are eukaryotes - yeasts are unicellular

fungi are photosynthetic (fungi are different from plants because fungi obtain their food from other organisms; they differ from animals by having cell walls)

Plasmids are extra chromosomal pieces of circular DNA that contain all of the following information EXCEPT __________. - resistance factors for resistance to drugs and heavy metals - virulence factors that allow a bacterium to become pathogenic - genes for cell division - fertility factors for conjugation - bacteriocins to kill bacterial competitors

genes for cell division

E. Coli can catabolize lactose to release what? (2)

glucose & galactose - these can be further catabolized as energy sources

What two components of bacterial external structures contribute to biofilms?

glycocalyces and fimbriae

external structures of bacterial cells (4)

glycocalyces, flagella, fimbriae, pili

Most often, antigens are composed of __________. - nucleic acids - lipids - glycoproteins - polysaccharides

glycoproteins

The ________ of a virion determines the type of cell it enters. - matrix proteins - glycoproteins - nucleic acid - shape - lipid molecules

glycoproteins

Review - What "unzips" the DNA helix?

helicase enzyme that use energy from ATP to break the hydrogen bonds of bases that hold the DNA molecule together

According to the animation, B cells interact directly with - inflammation. - the complement system. - phagocytes. - helper T cells.

helper T cells

Organotrophs

heterotrophs acquire electrons from same organic molecules that provide them carbon

What does HEPA stand for?

high-efficiency particulate air (filter)

Particulate Radiation

high-speed subatomic particles, such as protons, that have been freed from their atoms

Compared to moist heat methods, dry heat needs which of the following in order to sterilize effectively? - lower temperature and shorter time - lower temperature and increased time - higher temperature and increased time - higher temperature and shorter time

higher temperature and increased time - Air does not conduct heat as effectively as water does, so sterilization methods that rely on hot air require more time and higher temperatures than methods involving moisture.

Hyaluronic Acid - Extracellular Enzymes of Virulence Factors

holds cells together and collagen is the chief structural protein

Crenation can result from a change in which of the following? - hydrostatic pressure - osmotic pressure - temperature - pH

hydrostatic

Living cells are typically ___ (tonicity) to their environment?

hypertonic

Obligate anaerobes may be cultured in the laboratory... - in a reducing medium. - on blood agar plates. - in a standard incubator. - in standard complex media. - in standard Petri plates.

in a reducing medium.

How is the length of a DNA molecule expressed? (2)

in base pairs - most known bacteria have genomes of 1.5 - 6 million base pairs

How does algae differ from plants?

in the relative simplicity of their reproductive structures - NO: roots, stems, leaves, flowers, fruits, seeds, and cones

Review - What physical methods of microbial control oxidizes everything completely?

incineration (dry heat method)

logarithmic growth (3)

increase in size of a microbial population in which the number of cells doubles in a fixed interval of time - AKA "exponential growth" - in binary fission, # of cells arising is calculated as (# of cells that started) x 2^n (n is the number of generation) ex. 3 cells after 6 divisions(generations) 3 x 2^6 = 3 x 64 = 192

Temperature - enzyme reaction rate factors

increased temp, increased enzyme activity (until denaturation occurs)

Fever is beneficial during viral infection because the higher temperature: - increases vasodilation, contributing to inflammation. - prevents viral infection of fibroblasts. - inactivates interferons. - increases sweating and consequently the barrier effect. - increases the effectiveness of interferons.

increases the effectiveness of interferons

What are two hallmark characteristics of adaptive immunity?

inducibility and specificity

Which operons are never transcribed unless activated? - Inducible operons - Repressible operons - Inducible and repressible operons

inducible operons

Local Infection

infection confined to a small region of the body

Focal Infection

infection site that serves as a source of pathogens for infections at other sites in the body

** Which stages of bacterial translation require GTP energy?

initiation and elongation (GTP is equivalent to ATP)

Mucous membranes are a part of - innate defense. - the complement system. - cell-mediated immunity. - humoral immunity. - adaptive defense

innate defense

The first and second lines of defense against microbial invasion are part of: - adaptive immunity. - innate immunity. - microbial antagonism. - species resistance. - both species resistance and adaptive immunity.

innate immunity

Review - What physical methods of microbial control destroys DNA?

ionizing radiation (electron beams, gamma rays, X-rays)

Bacteria of the genus "Mycoplasma" lack cell walls. What sort of environment do they require for survival? - a biofilm - hypotonic - hypertonic - low temperature - isotonic

isotonic

What does it tell you to see a virus lacking an envelope?

it has a greater tolerance of harsh environmental conditions, including antimicrobial agents

All of the following are characteristics of RNA polymerase EXCEPT that __________. - it exhibits relatively slow polymerization - it proofreads - it does not require helicase - it incorporates ribonucleotides

it proofreads

A bacterial cell possesses a glycocalyx (capsule). Which of the following is FALSE? - it will be more pathogenic - it will be engulfed more quickly by defensive cells of the host - it will be able to attach to surfaces - it will be less likely to dry out

it will be engulfed more quickly by defensive cells of the host (it does the opposite and allows prokaryotes to pass undetected by defenses)

When is the repressor protein transcribed? - Only in the presence of tryptophan - Only in the absence of tryptophan - It is always transcribed.

it's always transcribed

What decides a protein's function? (2)

its exact 3D shape! - maintained by Hydrogen and Disulfate bonds between amino acids

Diapedesis

leukocytes exit the blood to attack invading microbes in the tissues by squeezing between the cells lining capillaries

Photophosphorylation

light energy is used to phosphorylate ADP with inorganic phosphate

Probiotics (2)

live microorganisms administered to improve health and prevent disease - may be needed in the future with the heavy use of antimicrobial agents in soaps

Microbial growth is at its maximum rate during which of the following phases of the microbial growth curve? - lag phase - log phase - stationary phase - death phase

log

Microbes in the __________ phase of the microbial growth curve are most susceptible to antimicrobial drugs. - death - stationary - lag - log

log - The rapid growth of cells during the log phase means they are more susceptible to antimicrobial drugs during this phase than in any other phase; many of these drugs interfere with the metabolism of the cell or with the synthesis of important cell structures.

Cell death occurs ____

logarithmically

Streptococci

long chains of cocci

How can EVERY disease be classified?

longevity and severity

Euchromatin

loosely packed chromatin fibers where genes are ACTIVE in a chromosome

Where do adaptive immune responses initiate? - site of infection - lymph nodes

lymph nodes - because antigen-presenting cells interact with lymphocytes here

During the lysogenic cycle, it is possible for integrated phage genes to change the characteristics of the host cell. This is known as _____. - induction - transduction - lysogenic conversion - synthesis

lysogenic conversion - Lysogenic conversion involves phenotypic changes to the bacterium due to new genes from the integration of the phage genome

What antibacterial chemical is present in tear fluid? - defensins - antibodies - lysozyme - complement - interferon

lysozyme

Temperate phages carry out two types of life cycle:

lytic cycle and lsyogenic cycle

Which of the following can be translated into protein? - mRNA - rRNA - tRNA - mRNA, tRNA, and rRNA are all translated into protein

mRNA

Transcription produces which of the following? - mRNA - rRNA - tRNA - mRNA and tRNA - mRNA and rRNA - mRNA, tRNA, and rRNA are all produced by transcription.

mRNA, tRNA, and rRNA are all produced by transcription.

Lectin Pathway of Complement Activation

mannose sugar, which is found on the surfaces of fungi, bacteria, and viruses, attaches to activating molecules called lectins. This begins the series of enzyme activities as in the classical activation pathway, leading to a complement cascade

What viral proteins fill the region between capsid and envelope?

matrix proteins

Which of the following techniques is most useful for measuring microbial reproduction when the density of a microbial population is very small? - membrane filtration - viable plate counts - turbidity - microscopic counts

membrane filtration

The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. What component of the immune system will protect her from getting the same cold again? - Antibodies that are "left over" from the last infection - Dendritic cells - Memory B cells - Plasma cells

memory B cells - Memory cells to that specific virus are stored in the lymph nodes for many years. When the student comes into contact with this specific Rhinovirus, these memory cells quickly divide and differentiate into antibody-producing plasma cells. The antibodies will prevent the virus from reaching an infectious titer (number that causes infection).

Review - Refrigeration halts the growth of most pathogens, which are predominantly ___.

mesophiles

** What is the first amino acid for eukaryotes?

methionine

Extremophiles (2)

microbes that require extreme conditions of temperature, pH, pressure, and/or salinity to survive - thermophiles and halophiles are prominent

normal microbiota (2)

microorganisms assoc. w/ a certain area of the body without causing disease - often collected along with pathogens in clinical specimen

During mitosis, duplicated chromatin fulls condenses into a ___ visible by light microscopy.

mitotic chromosome

What kind of environment do microorganisms need in order to be metabolically active?

moist They need water!

Microscopic fungi include some: (2)

molds and yeasts

All polymerization processes require ___ and energy.

monomers

* Anabolic polymerization process requires ___ and ___.

monomers and energy - Triphosphate deoxyribonucleotides serve both functions (nucleotide bases)

Taxis (6)

movement in response to a stimulus - Phototaxis (light stimuli) - Chemotaxis (chemical stimuli) - Negative taxis (away from unfavorable stimuli) - Positive taxis (towards favorable stimuli) ex. positive chemotaxis

What happens if TLRs fail?

much of an immune response collapses, leaving the body open to attack by myriad pathogens

What are the successful descendants of a mutation called?

mutants - descendants of a cell that doesn't repair a mutation

Most commonly used antimicrobials are either ___ or ___

natural or semisynthetic

What type of immunity is produced by the body when a person contracts a disease? - artificially acquired passive immunity - naturally acquired active immunity - innate immunity - naturally acquired passive immunity - artificially acquired active immunity

naturally acquired active immunity

collecting cerebrospinal fluid

needle aspiration from subarachnoid space of spinal column

Is a virus a prokaryote or eukaryote?

neither

A cell is infected with a virus carrying an oncogene sequence in its genome. What process may occur if the oncogene is expressed in the infected cell? - neoplasia - lysogeny - lysis - latency - both lysis and neoplasia

neoplasia

Is oxygen required for fermentation?

no

Do genes directly code for such molecules as phospholipids or behavior such as chemotaxis? (5)

no - Ultimately phenotypic traits result from the actions of RNA and protein molecules that are themselves coded by DNA - not all genes are active at all times —> the info of a genotype is not always expressed as a phenotype ex. E. Coli activates genes for lactose catabolism only when it detects lactose in its environment

Is every molecule an effective antigen?

no - different properties make certain molecules more effective at provoking adaptive immunity --> shape, size, complexity

Are animal cells quickly lysed?

no (that occurs in bacteriophage replication)

Ribosomes contain which of the following? - mRNA - mRNA, tRNA, and rRNA are all found as part of the ribosome. - rRNA - tRNA

rRNA

Which of the following is a true statement concerning bacteria and archaea? - bacteria are only found in extreme environments - while some bacteria are pathogenic to humans, no archaea are known to cause human diseases - bacteria and archaea have identical cell walls - bacteria reproduce asexually, while archaea reproduce sexually

no archaea are known to cause human diseases (bacteria are everywhere; bacteria and archaea have different cell walls; members of both groups reproduce asexually)

If there are 61 mRNA codons, do we need 61 tRNA anticodons? (4)

no! - many tRNA molecules recognize more than one codon - the anticodon's third nucleotide "wobbles" (changes its normal molecule axis) - this allows it to Hydrogen bond to a nucleotide other than its usual complement

Are all viruses deleterious? (4)

no! - one virus inhibits algal blooms that would otherwise deplete water sources of oxygen --> when the algal cells die this way, a death by-product seeds clouds, measurably lowering temperature (helps reduce global warming) - a bacteriophage of oceanic cyanobacteria transfers photosynthetic genes to its host, increasing its photosynthetic rate --> much of the air we breath may be attributable to this viral action on blue-green bacteria

Under normal circumstances, do normal microbiota cause disease?

no! but they can become Opportunistic Pathogens (opportunists)

Do ribosomes directly access genetic information on a DNA molecule?

no! mRNA carries the code to the ribosomes

Is disinfection adequate for mucous membrane contact if the patient is immunocompromised?

no! sterilization is usually required if the patient is immunocompromised

Are archaeal DNA replication processes well understood?

no, the book doesn't cover them

Introns - book definition

noncoding sequence of mRNA that is removed to make functional mRNA

Review - What physical methods of microbial control forms Thymine Dimers that inhibit DNA replication and transcription?

nonionizing radiation (UV light)

Which of the following types of mutations creates a stop codon where one did not exist before? - frameshift mutation - missense mutation - nonsense mutation - silent mutation

nonsense mutation

Are flagella present on all bacteria?

nope!

Do gamma rays change the taste or nutritional value of food?

nope!

The ___ is the genetic material (genome) of the virus.

nucleic acid

What cellular macromolecule is the fertility factor comprised of? - Carbohydrate - Nucleic acid - Protein - Lipid

nucleic acid

* DNA polymerase III proofreading exonuclease function has what error count?

one error for every 10 billion bp replicated

What is a colony-forming unit? - a type of media that allows only one type of bacteria to grow - one or more cells that give rise to an assemblage of identical cells - a unit of measure equal to the mass of one bacterium - a single agar plate with various different species of microorganisms

one or more cells that give rise to an assemblage of identical cells - Bacterial colonies usually begin as a single bacterium or group of bacteria that then reproduces into a large "colony" of like bacteria.

On that plane to bacilli divide?

only the transverse plane (their chains look like sausage links!)

Which of the following is the regulatory sequence responsible for control of an operon? - the promoter - the corepressor - the operator - the release factor

operator

With which genetic region does the repressor protein interact? - The promoter region - The regulatory gene - lacY - lacZ - The operator region

operator region

Halophiles (5)

organisms that inhabit extremely saline habitats - phylum Euryarchaeota - depend on >9% NaCL to maintain integrity of cell walls - optimum range for most is 17-23% salt - many contain red to orange pigments that play a role in protection from intense sunlight

Damage to the cell wall will adversely affect a bacterial cell by making it more susceptible to __________. - osmotic pressure - high temperature - radiation - alcohols

osmotic pressure - Without a strong, functional cell wall, the bacterial cell cannot resist sudden changes in osmotic pressure and can die as a result.

What stops DNA strands from rejoining?

other protein molecules

Aerobic respiration

oxygen serves as the final electron acceptor

If an epidemic occurs simultaneously on more than one continent, it is referred to as a ____

pandemic

Any parasite that causes disease is called a:

pathogen

PBP (2)

penicillin binding protein - the enzyme that catalyzes the crosslink of amino acids to form the tetrapeptide binding NAM molecules in peptidoglycan

Nucleoside

pentose sugar + nitrogenous base (ribose in RNA; deoxyribose in DNA) + a nitrogenous base (G, C, T, A, or U)

Attachment of viruses can be blocked by ___ and ___ analogs of either attachment or receptor proteins. When analogs block these sites, viruses can neither attach to nor enter their host's cells.

peptide sugar

What kind of bond is formed when two amino acids join together? - A hydrogen bond - A polar bond - A peptide bond - An ionic bond

peptide bond - Amino acids are joined together with a peptide bond. This occurs, for example, between the A and P sites of the ribosome

Which of the following would NOT be expected to be present in a biochemical analysis of an archaeal cell? - peptidoglycan - membrane proteins - phospholipids - ribosomes

peptidoglycan

Bacterial cell walls are composed of:

peptidoglycan, a mesh-like polysaccharide

The region between the out and inner membranes of a Gram-negative bacterial cell is known as the ___, and is the location of enzymes that assemble peptidoglycan. - cytoplasm - intramembranous space - lipopolysaccharide layer - periplasmic space

periplasmic space (an area surrounding the bacterial cytoplasmic membrane)

Which structure do antigen presenting cells utilize to directly help them present bacterial antigens? - Golgi apparatus - Mitochondria - Phagolysosome - Nucleus

phagolysosome

Viroids infect: - fungi. - bacteria. - all organisms. - plants. - plants and animals.

plants

Fungi, algae, and protozoa have extracellular DNA in mitochondria and chloroplasts. What else do some carry? (4)

plasmids! ex. most strains of brewer's yeast (Saccaromyces cerevisiae) contain 70 copies of a plasmic called a 2-um circle - each is about 6,300 bp long - has 4 protein-encoding genes involved solely in replicating the plasmid and confer no other traits to the cell

Cytoskeleton 4 functions shortened

plays roles in: - cell division - cell shape - segregates DNA molecules - can help move the cell through environment

Log Phase - 2/4 phases of microbial growth (5)

population increases logarithmically - exponential phase - populations in log phase are more susceptible to antimicrobial drugs that interfere with metabolism and cell structure formation - populations in log phase are preferred for Gram staining because most cells' walls are intact - also preferred because metabolic rate is at max here and is more useful for industrial and lab purposes

Note that higher temperatures (and consequently, greater antimicrobial action) are associated with higher ____.

pressures

What is used to synthesize an RNA primer?

primase

Templating

prion PrP acts as a template to refold molecules of normal, cellular PrP into Prion PrP

Methanogens (6)

produces methane gas - make up the largest known group of archaea in the phylum Euryarchaeota - converts Carbon Dioxide, Hydrogen gas, and organic acids into methane gas - a few are thermophilic and halophilic - some live in animal colons and are one of the primary sources of environmental methane (cows) - have produced 10 trillion tons of methane buried in the mud of the ocean floor - converts organic wastes in pond, lake, and ocean sediments into methane

Apoptosis is the process of __________. - differentiating into a regulatory T cell - presenting epitope in an MHC protein - programmed cell death - multiplying into a clone repertoire

programmed cell death - T cells that undergo apoptosis commit suicide and are deleted from the immune cell population

Microorganisms characterized by the absence of a nucleus are called:

prokaryotes

Hyperthermophiles

prokaryotes that requires temps over 80 degrees C (176 F)

Hopanoids (2)

prokaryotes use _____ instead of cholesterol in their plasma membranes - sterol-like molecules that help stabilize the bacterial cytoplasmic membrane

Thermophiles (3)

prokaryotes whose DNA, RNA, cytoplasmic membranes, and proteins don't function properly at temps lower than 45 degrees C (113 F) - most thermophilic archaea are in the phylum Crenarchaeota - some are in the phylum Euryarchaetota

Antimicrobial agents that damage nucleic acids also affect: - the viral envelope. - endospores. - protein synthesis. - the cell membrane. - the cell wall.

protein synthesis

Review - what performs the activities necessary to keep the cell alive?

proteins

Which of the following is an INCORRECT pairing? - fungi; cell walls - viruses; acellular parasites - protozoa; multicellular - algae; aquatic and marine habitats - prokaryotes; no nuclei

protozoa; multicelluar (protozoa are single-celled organisms)

__________ are used for communication by the microbes in biofilms. - water channels - quorum-sensing molecules - matrix - streamers

quorum-sensing molecules

A chemoheterotroph obtains its energy from __________ and its carbon from __________ sources. - light; organic - redox reactions; inorganic - redox reactions; organic - light; inorganic

redox reactions; organic

Which operons are always transcribed unless deactivated? - Inducible operons - Repressible operons - Inducible and repressible operons

repressible operons

What is the ultimate outcome of metabolic activity?

reproduction - an ncrease in the number of individual cells or organisms

Using. microscope, you observe an amoeba moving toward a food source. This is an example of: - reproduction - cellular structure - responsiveness - growth - metabolism

responsiveness

Reverse transcriptase is associated with which of the following? +ssRNA viruses -ssRNA viruses retroviruses dsDNA viruses dsRNA viruses

retroviruses

Genomes of RNA viruses are composed of:

ribonucleic acid (RNA)

What part of the ribosome catalyzes protein synthesis?

ribozyme - an enzymatic RNA molecule

Bacilli (2)

rod-shaped bacteria - typically appear singly or in chains

What yeasts causes bread to rise & produces alcohol from sugar?

saccharomyces cerevisiae

The process of phagocytosis involve all of the following EXCEPT: - vesicle fusion. - secretion of cytotoxins. - adhesion. - chemotaxis. - elimination.

secretion of cytotoxins

Which type of media is used to prevent the growth of certain microbes while allowing the growth of others?

selective media

Which of the following is NOT a basic process of life? - sexual reproduction - metabolism - responsiveness - growth

sexual reproduction (not all living organisms reproduce sexually)

Gene Silencing

siRNAs unwind and join RISC proteins to form siRISC, which appears to always bind to and cut the target nucleic acid

All of the following are associated with the process of DNA replication EXCEPT __________. - sigma factors - DNA ligase - primase - helicase

sigma factors

Passive transport includes

simple diffusion (net movement of a chemical down its concentration gradient) nonspecific/specific facilitated diffusion (permeases facilitate movement process using electrochemical gradients) osmosis (the diffusion of water across a semipermeable membrane based on solute concentration)

Axenic

sites free of any microbes

Is slow or quick freezing more efficient at inhibiting microbial growth?

slow freezing is more effective! - ice crystals have time to form & puncture cell membranes

What types of molecules may NOT need transport proteins to be able to cross cytoplasmic membranes? - small hydrophilic molecules - nothing crosses cytoplasmic membranes without transport molecules - ions - large molecules - small hydrophobic molecules

small hydrophobic molecules

What triggers induction? (2)

some alteration to the bacterial DNA - host cell damage (UV lights, X-rays, chemicals) - bacterial health decreasing

How do structural differences between Prok. and Euk. ribosomes play a role in the efficacy and safety of microbial drugs?

some drugs only bind to specific ribosomes ex. Erythromycin binds only to the 23S rRNA found in prokaryotic ribosomes - it doesn't affect 80S ribosomes - BUT! mitochondrial and chloroplasts ribosomes are 70S and are considered prokaryotic! - 80S cytosol and RER would not be affected

Do eukaryotic cells contain plasmids?

some eukaryotic cells do

Inducibility

specific antigen-containing pathogen activates or induces cells of adaptive immunity

Genes

specific sequences of nucleotides that code for DNA or polypeptide molecules

Cocci (5)

spherical bacteria that may appear in various arrangements depending on the planes of cell division - single arrangement - chain arrangement (streptococci) - clusters (staphylococci) - cuboidal packets (sarcinae)

Review - What holds the single-stranded DNA apart and protects them from degradation?

stabilized proteins

Mice that are injected with only the R strain of Streptococcus pneumoniae: - become sick for prolonged periods of time. - are killed, because R strain cells are deadly. - stay healthy, because their immune systems can kill this strain easily.

stay healthy, because their immune systems can kill this strain easily. (R strain = rough, unencapsulated)

Which is lighter: steam or air?

steam is lighter than air! Therefore, steam cannot force air out of an empty vessel. Empty vessels must be tipped so air can flow out.

Koch's Postulates definition

steps necessary to prove the cause of any infectious disease

Collection method for skin/accessible membrane/open wounds (2)

sterile swab brushed across surface - don't touch neighboring surfaces

Polyribosome (2)

string of ribosomes simultaneously translating regions of the same mRNA strand during protein synthesis - as elongation proceeds, ribosomal movement exposes the Start AUG codon, allowing other ribosomes to attach behind the first one

endocytosis by archaea

substances are surrounded by pseudopods and brought into the cell

-statis -static (suffixes)

suffixes indicating INHIBITION but NOT complete destruction of a type of microbe - germistatic agents: some chemicals, refrigeration, and freezing

-cide -cidal (suffixes)

suffixes indicating the DESTRUCTION of a type of microbe - germicides: ethylene oxide; propylene oxide; aldehydes

Collecting diseased tissue

surgical removal (biopsy)

Diffusion susceptibility tests enable scientists to classify pathogens as ___, ___, or ___ to each drug.

susceptible intermediate resistant

Once entry into the bacterial cell has been achieved, the next step in a lytic replication cycle is _____ - assembly - synthesis - release - attachment

synthesis

Which of the following is involved in bringing amino acids to the ribosomes? - mRNA, tRNA, and rRNA are all involved in transporting amino acids to the ribosomes. - mRNA - rRNA - tRNA

tRNA

Which of the following contributes to protecting the eyes from microbial invasion? - tears contain lysozyme and salt. - a mucus layer traps and removes microbes. - tears mechanically flush particles from the eyes. - tears contain lysozyme and salt and mechanically flush particles from the eyes. - tears and mucus combine to trap microbes and remove them.

tears contain lysozyme and salt and mechanically flush particles from the eyes

2 Special Culture Techniques (3)

techniques developed for culturing microorganisms for which artificial media are inadequate - animal and cell culture - low-oxygen culture

One chain of alternating NAGs and NAMs is connected to another chain via ___. - tetrapeptides - enzymes - lipids - teichoic acids

tetrapeptides (composed of 4 amino acids and make up the "peptide" portion of peptidoglycan)

When a transducing phage interacts with a new host cell, - it will cause the new cell to produce more transducing phage. - the new host cell will be lysed. - the DNA from the previous host can recombine with the new host chromosome.

the DNA from the previous host can recombine with the new host chromosome.

What is the first step of a cell-mediated immunity response?

the activation of a specific clone of cytotoxic T cells

Cell-mediated adaptive immune responses involve:

the activity of cytotoxic T lymphocytes in killing cells infected with intracellular bacteria and viruses

In a lytic cycle of replication, release of phages involves _____. - exocytosis of phages across the cell wall - contact with another uninfected bacterium - the bacterial cell bursting open - keeping the host cell alive

the bacterial cell bursting open - The bacterial cell undergoes lysis, meaning that it is destroyed. Phages are then released.

A bacterial cell is placed in distilled water. Which of the following will happen? - the cell will lose water - the cell will gain water - the cell will shrink - there will be no net gain or loss of water in the cell

the cell will gain water

A sick child may have influenza or RSV. These virus infections have different treatment options, so the physician requests antibody titer tests. The results are as follows: anti-influenza antibodies are primarily IgM, and anti-RSV antibodies are all IgA and IgG. Which of the following is the most appropriate interpretation? - the child has a current RSV infection and was previously exposed to influenza. - the child currently has influenza and has previously been exposed to RSV. - the child has concurrent influenza and RSV infections. - the child has neither influenza nor RSV. the results do not provide sufficient data to draw a conclusion.

the child currently has influenza and has previously been exposed to RSV

Opsonization is: - the sticking of monocytes to the wall of the blood vessels at the site of infection. - damage resulting in cell lysis. - nonspecific leukocyte secretion of toxins onto the surface of virally infected cells. - the coating of a pathogen by complement to facilitate phagocytosis. - phagocyte receptors detecting PAMPs.

the coating of a pathogen by complement to facilitate phagocytosis

What is the key to DNA replication?

the complementary base paired structure of the two strands

If all of the tested antimicrobial agents diffuse at the same rate and are equally safe and easily administered, which one would be the drug of choice for killing this pathogen?

the drug that produced the largest zone of inhibition on the plate

Why is lysogeny advantageous to a bacteriophage? - the genetic material of the bacteriophage is amplified many times over that seen in a lytic phage. - it enables the bacteriophage to take over the cell. - it allows the bacteriophage to infect cells it would not normally infect. - it speeds up the viral infection cycle. - it allows the bacteriophage to destroy the host cell's DNA.

the genetic material of the bacteriophage is amplified many times over that seen in a lytic phage

DNA Triplets (4)

the group of three bases in DNA - each triplet specifies a particular amino acid - there are 64 arrangements for the 4 nucleotides in triplets (4^3) —> more than enough to code all 20 amino acids

Maximum Growth Temperature (2)

the highest temp at which an organism continues to metabolize - when the temp exceeds this value, the organism's proteins are permanently denatured and it dies

Handwashing with regular soap is effective because __________. - the fatty acid tail of a soap molecule is an excellent oxidizing agent, while the opposite end of the molecule contains alcohol - the hydrophobic end of the soap molecule attaches to the cell wall of bacteria and the hydrophilic end of the molecule attracts water. The result is that the bacteria are washed away with the water - the hydrophobic end of the soap molecule breaks up oily deposits and the hydrophilic end of the molecule attracts water. This combination makes soap a good de-germing agent - soap is an excellent antimicrobial agent

the hydrophobic end of the soap molecule breaks up oily deposits and the hydrophilic end of the molecule attracts water. This combination makes soap a good de-germing agent

Infection

the invasion of the host by a pathogen

Minimum Growth Temperature (2)

the lowest temp at which an organism is able to conduct metabolism - many microbes (particularly bacteria) can survive (not thrive though) at temps far below their minimum growth temp

Thermal Death Point

the lowest temperature that kills all cells in a broth in 10 minutes

Thermal Death Time

the time it takes to completely sterilize a particular volume of liquid at a set temperature

A patient is infected with Gram-negative bacteria and is experiencing only mild symptoms. When the patient is given an antibiotic causing lysis of the bacterial cells, he suddenly experiences an increase in inflammation and fever, as well and the formation of blood clots. What explanation best describes what happened? - the lysis of the cells releases lipid A form the LPS layer - the antibiotic is toxic and is affecting the patient adversely - the lysis of the cells releases NAG and NAM from the cell wall - any part of the bacterial cell wall released during lysis is seen as foreign and thereby elicits a severe immune response by the body's immune system

the lysis of cells releases lipid A from the lipopolysaccharide layer (lipid A "endotoxin" is known to cause inflammation, fever, and blood clots)

Cardinal Temperatures

the minimum, optimum, and maximum temperatures at which an organism grows

The phenomenon known as chemotaxis is defined as: - the movement of a cell toward or away from a chemical stimulus. - an increase in allergies and helminth infection. - the coating of a pathogen by complement. - the squeezing of cells through the lining of capillaries. - the release of prostaglandins and leukotrienes in response to microbes

the movement of a cell toward or away from a chemical stimulus.

Burst Size

the number of new virions released from each lysed bacterial cell

According to the animation, where on the DNA strand does a repressor bind? - The structural genes - The inducer - The operator - The promoter

the operator

Lipid A is a component of: - the outer membrane of Gram-negative bacteria - Gram-positive bacterial membranes - plant cell walls - bacterial glycocalyces - cytoplasmic membranes

the outer membrane of Gram-negative bacteria

A major difference between the lytic and lysogenic cycles of phage replication is that during the lysogenic phase _____. - the bacterial cell is broken open, destroying the cell - the host DNA is degraded - the phage genome inserts itself into the host genome - attachment of the phage involves a random collision

the phage genome inserts itself into the host genome - The phage DNA is integrated into the host DNA without destroying the cell

What is the purpose of liver extract in an Ames test?

the presence of liver extract simulates the conditions in the body under which liver enzymes can turn harmless chemicals into mutagens

Viviparity (3)

the production of live offspring within a mother ex. Epulopiscium is a giant bacteria in surgeonfish that give "birth" to as many as 12 live offspring that emerge from the body of the dead mother cell. This is the first documented case of viviparous behavior in the prokaryotic world.

Review - What is the site where DNA "unzips" called?

the replication fork

When the cell is not in the presence of lactose, - the repressor proteins are inactivated. - no transcription of the regulatory genes occurs. - the repressor proteins bind to the operator. - transcription of the structural genes occurs

the repressor proteins bind to the operator.

Antibody adaptive immunity involves:

the secretion of specific antibodies that have a variety of functions - T-dependent antibody immune response occurs when an APC binds to a specific Th cell and signals the Th cell to proliferate

Review - What is important for virion attachment to the host cell?

the specific attraction between the virus and the host's surface proteins

Due to the action of tears, potential pathogens of the eyes and its membranes usually end up where? - the stomach - the bloodstream - the lungs - the skin

the stomach - Tears (and the microbes collected by them) flow into the nose through a series of canals and ducts; here, they mix with nasal mucus and pass into the pharynx, where they are swallowed.

Etiology

the study of the cause of a disease

epidemiology

the study of the occurrence and spread of diseases within groups of humans

Epidemiology

the study of where and when diseases occur and how they are transmitted within populations

Optimum Growth Temperature

the temp at which an organism's metabolic activities produce the highest growth rate

Where is the antigen-binding site on BCRs?

the variable region at the end of the arms! - they are complementary in shape to the 3D shape of an epitope - exact binding accounts for the specificity of an antibody immune response

Which of the following is NOT a characteristic of protozoa? - most exhibit asexual reproduction - they are single-celled organisms - they are all photosynthetic - they are eukaryotic - the frequently possess cilia or flagella

they are all photosynthetic (they are similar to animals in their nutritional needs and cellular structure)

Which of the following is NOT a characteristic of viruses? - the are composed of genetic material and protein - the are acellular - they are typically smaller than prokaryotic cells - they are visible with a light microscope - they are obligatory parasites

they are visible with a light microscope (they weren't seen until 1932 with the invention of the electron microscope)

Can doctors use interferons to help patients?

they can administer interferons created using recombinant DNA techniques can activate immune responses to help patients fight viral infections and cancers

Microbiologists study parasitic worms because ___. - they usually contain bacteria and other microbes - they were not studied by early microbiologists - they are microscopic as adults - they cause diseases that are diagnosed by finding microscopic eggs in clinical specimens

they cause diseases that are diagnosed by finding microscopic eggs in clinical specimens (they WERE studied by early microbiologists; they are NOT microscopic as adults)

How are prions different from all other known infectious agents? - How are prions different from all other known infectious agents? - They lack nucleic acid. - They act as slow viruses. - They cause neurological problems. - They can be destroyed by incineration. - They cannot reproduce outside a cell.

they lack nucleic acid

Which of the following is characteristic of archaea? - They lack peptidoglycan cell walls. - N-formylmethionine is the initial amino acid in their proteins. - They frequently cause human disease. - Their plasma membranes contain lipids with straight hydrocarbon chains.

they lack peptidoglycan cell walls

What role do the teichoic acids play within the cell wall of Gram-positive bacteria? They serve: - as adhesins, allow bacteria to bind to one another -as cross-bridges, holding the peptides and sugar molecules together - as pores, allowing the passage of ions, nutrients and amino acids into the cell - to stabilize the cell walls and hold it in place

they serve to stabilize the cell and hold it in place (the teichoic acids anchored to lipids within the cytoplasmic membrane are called "Lipoteichoic Acids"

How are mutations in unicellular organisms passed on?

they're passed on to the organism's progeny/offspring

One of the main differences betweem a Gram-positive and a Gram-negative bacterial cell wall is that the peptidoglycan portion of a Gram-positive cell wall is ___ as compared to a Gram-negative cell wall. - positively charged - more lipid rich - composed of a greater percentage of NAGS than NAMS - thicker

thicker (it's much thicker than Gram-negative's layer)

Clonal deletion occurs in the __________. bone marrow blood thymus thyroid

thymus - thymus is where the T cells migrate to mature and also where they may undergo clonal deletion.

Heterochromatin

tightly packed chromatin fibers where genes are INACTIVE in a chromosome

How can conjugation give us info about gene mapping?

timing conjugation and observing the transferred genes tells researchers about where on the genome each amino acid lies

What is the critical function of DNA?

to carry information in sequences of nucleotide bases in DNA and RNA molecules

* 3 Types of Horizontal Gene Transfer

transformation, transduction, conjugation

Which of the following processes are INCORRECTLY paired? - conjugation: the transfer of chromosomal DNA from one bacterium to another through a pilus - crossing over: occurs during prophase I and creates new genetic combination - transduction: the transfer of genes between bacteria through a phage infection - transformation: the spontaneous change of genetic information in a species that creates deleterious mutations

transformation: the spontaneous change of genetic information in a species that creates deleterious mutations

Codons

triplets of mRNA nucleotides that code for specific amino acids

BCRs of one cell differ from the BCRs of all other B cells. T/F

true

Because an antigen (e.g., a bacterial protein) typically has numerous epitopes of various shapes, many different BCRs will recognize any particular antigen, though each BCR recognizes only one epitope of that antigen. T/F

true

Eukaryotic genomes consist of both Nuclear and Extranuclear chromosomes. T/F

true

Microbes that are parasitic may become mutualistic, or vice versa; that is, the relationships between and among organisms can change over time. T/F

true

Most prokaryotes have a cell wall. T/F

true

The majority of bacteria don't cause disease in animals, humans or crops. T/F

true

The majority of prokaryotes have not been grown in culture medium. T/F

true

Using an alcohol pad before taking a blood sample is an example of antisepsis. T/F

true

Cells must continualy synthesize proteins required for growth, reproduction, metabolism, and regulation. T/F

true - This requires that the genetic info in DNA nucleotide sequences must be transferred to the amino acid sequences of proteins.

Amino acids have no direct affinity for or recognition of mRNA codons. T/F

true - tRNA carries the correct amino acid to a ribosome during polypeptide synthesis

Thanks to the segregation of electrical charges by a membrane, the interior of a cell is usually electrically negative compared to the exterior. T/F

true - this tends to repel negatively charged chemicals and attract positively charged substances into cells

** Nitrogen is often a growth-limiting nutrient for many organisms. T/F

true Anabolism ceases because they do not ave sufficient nitrogen to build proteins and nucleotides.

Some genes are regulated so that the polypeptides they encode are only synthesized in response to a change in environment. T/F

true ex. Pseuomonas aeruginosa uses quorum sensing to detect high levels of bacteria before producing harmful proteins in cystic fibrosis patients

Cells of adaptive immunity ONLY recognize epitopes that are bound to MHC molecules. T/F

true!

MHC class II glycoproteins are expressed only by B cells and special antigen-presenting cells (APCs). T/F

true!

Slow freezing is more damaging to microbial cells than quick freezing. T/F

true!

Some doctors recommend that patient refrain from taking taking fever-reducing drugs unless the fever is prolonged or extremely high. T/F

true!

At higher elevations, water boils at lower temperatures because the atmospheric pressure is lower. T/F

true! - thus, a longer boiling time is required in Denver than in Los Angeles to get the same antimicrobial effect

All living things contain both organic and inorganic chemicals. T/F

true! Many organic chemicals can be made from inorganic materials by laboratory processes.

With most redundant codons, the first 2 nucleotides determine the amino acid. The third is in consequential. T/F

true! This redundancy helps protect cells against the effects fo errors in replication and transcription

When speaking of microbial reproductive activities and of bacteria in particular, microbiologists use the term growth. T/F

true! referring to an increase in the size of a population of microbes rather than to an increase in size of an individual

What is an example of a repressible operon?

tryptophan (trp) operon

What results when a single bacterium reproduces? - One parent cell and a genetically different cell - One parent cell and a genetically identical daughter cell - Two genetically unique daughter cells - Two genetically identical daughter cells

two genetically identical daughter cells

Milk that can be stored for months at room temperature has been treated by which of the following methods? - flash pasteurization - ultrahigh-temperature sterilization - batch pasteurization - ultrahigh-temperature pasteurization

ultrahigh-temperature sterilization - Ultrahigh-temperature sterilization kills all forms of living microbes: UHT-sterilized milk can be kept at room temperature indefinitely without spoilage, although flavor changes may occur.

If a T cell recognizes MHC in conjunction with autoantigens, it will either __________ or differentiate to become a regulatory T cell. - undergo apoptosis - differentiate to become a cytotoxic T cell - differentiate to become a B cell - divide into a repertoire of T cells

undergo apoptosis - Yes. If a T cell recognizes autoantigen, it must undergo apoptosis to prevent the formation of progeny and against self. This could lead to an autoimmune disease.

Why do intramuscular or one-time intravenous drug concentrations diminish so quickly?

unless the drug is continuously administered, the concentration can rapidly diminish as the liver and kidneys remove the drug from the circulation

Pleomorphic bacteria... - vary in size and shape. - are both bacillus and coccobacillus in shape. - are flexible spirals. - have a slightly curved rod shape. - are roughly spherical

vary in shape and size

Which of the following is most susceptible to antimicrobial agents? - mycobacteria - protozoan cysts - bacterial endospores - vegetative bacteria

vegetative bacteria - Vegetative bacteria are active metabolically and will typically be more susceptible to antimicrobial control methods.

Small circular RNAs called ________ are plant pathogens - viroids - phages - plasmids - viruses - prions

viroids

Which of the following infectious particles do NOT have protein in their structure? - bacteriophages - prions - animal viruses - viroids - both prions and viroids

viroids

What are the most common intracellular pathogens?

viruses

What type of microbe did Leeuwenhoek not describe? Why?

viruses - they're too small to be seen without an electron microscope

*** How many total ATP are produced from glucose catabolism? (3)

we have 10 NADH molecules; each has an electron that can create 3 ATP. (30) we have 2 FADH molecules; each has an electron that can create 2 ATP. (4) we have 2 ATP from glycolysis. (2) we have 2 ATP from kreb's (each acetyl-CoA provides 1 entering K cycle) (2) ~38 ATP molecules are formed during chemiosmosis from one molecule of glucose

Genotype determines phenotype by specifying what?

what kinds of RNA and which structural, enzymatic, and regulatory protein molecules are produced

Hypertonic (3)

when comparing two solutions, the solution with the greater concentration of solutes - cells in hypertonic solutions shrink because of the net movement of water out of the cell — can cause the cell to shrivel (crenation)

Hypotonic (4)

when comparing two solutions, the solution with the lesser concentration of solutes - cells in a hypotonic solution undergo a net gain of water - animal cells burst due to lack of a cell wall - in cells with a cell wall, the pressure of water pushing against the interior of the wall eventually stops the net gain

When does the second line of defense operate?

when pathogens penetrate the skin or mucous membrane

Isotonic (2)

when the concentration of two solutions is the same - no net movement of water in/out of a cell

The tryptophan operon is described as repressible because __________. - it is not usually transcribed and must be activated - it is usually transcribed and must be deactivated - when tryptophan is available, it activates a repressor that blocks transcription - it is transcribed when ATP levels are repressed

when tryptophan is available, it activates a repressor that blocks transcription

What is a non-mutant cell called?

wild-type cell - a cell normally found in nature

Role of Public Health Agencies (6)

work to limit disease transmission - Enforce cleanliness of water and food supplies - Work to reduce disease vectors and reservoirs - Establish and enforce immunization schedules - Locate and treat individuals exposed to contagious pathogens - Establish isolation and quarantine measures

Would a third exposure be even more powerful than the second?

yes

Is it possible for pathogens to have more than one type of adhesion? Can they change their adhesion(s) over time?

yes to both! Changing their adhesions can help the pathogen evade the body's immune system and allowing the pathogen to attack more than one kind of cell

Can disease be classified according to body system?

yes!

Do eukaryotic flagellum have a membrane covering the filament?

yes!

Can adaptive immunity harm body cells?

yes! - the body regulates adaptive immune responses to prevent damage - Ex. an immune response requires multiple chemical signals before proceeding --> thus reducing the possibility that an immune response will be randomly triggered against uninfected healthy tissue --> Autoimmune disorders, hypersensitivities, or immunodeficiency diseases result when regulation is insufficient or overexcited

Does the structure of DNA help it act as genetic material?

yes! 1. liner sequence of nucleotides carries instructions for synthesis of polypeptides and RNA molecules (similar to how letter order synthesizes words) 2. the complementary structure of the 2 strands allows a cell to make exact copies t pass to its progeny (offspring)

Is it possible to be infected but not yet diseased?

yes! (ex. HIV)

Do archaea have cell walls and cytoplasmic membranes?

yes, as do bacteria But there are differences between the two.