Microbiology
Chargaff's 1st Rule
"DNA from any cell of all organisms should have a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases; the amount of *guanine is approximately equal to cytosine* and the amount of *adenine is approximately equal to thymine*." [A]=[T] and [G]=[C]; They pair up across from one another forming two strands called base pairing.
Mitochondria
"Powerhouse of the cell" -Smooth outer membrane and an inner membrane folded into cristae -provides larger surface area -The inner membrane creates two compartments: inter-membrane space and mitochondrial matrix
Antibodies (immunoglobulins)
"Y" shaped molecules that are used to attack foreign proteins and pathogens; these molecules can combine with each other, forming complex symmetrical structures effective against a wider range of disease. These molecules have TWO DISTINCT REGIONS: Variable (v) regions: the region of the antibody at the end of the chain that binds to the antigen or epitope(s). These regions are subject to change. Constant (Fc) regions: the region of the antibody that conveys which isotope of the antibody it is. These regions aren't subject to change; it's like the stem of a plant. The five classes (isotopes) of Ig: IgG, IgM, IgA, IgD, IgE CHAINS The "Y" shape of the antibody is due to the two identical light chains and two identical heavy chains, joined by disulfide links •Four protein chains form the "Y" shape
Microvilli
"finger-like" extensions of plasma membrane of apical epithelial cells that increase surface area, aid in absorbtion, and exist on every moist epithelia. • They are the most dense in small intestine and kidney
DNA polymerase 3
"proofreads" the original DNA template strand [3'-5'] and synthesizes the new strand [5'-3'] towards the replication fork.
Halophiles
"salt-loving" archaea that live in environments that have very high salt concentrations (high osmotic pressure). Obligate halophiles: microorganisms that can only survive in high salt concentration environments. Facultative halophiles: able to survive in both high and normal salt concentration environments.
filamentous
"thread-like" complex bacteria shape; chains of cells attached end to end
The Golden Age of Microbiology (1857-1914)
(1857-1914) Beginning with Pasteur's work; a period of eminent discoveries including the *relationship between microbes and disease*, *immunity*, and *antimicrobial drugs* The invention of the light microscope allows even small minute particles to be observed and people became curious. This led to the *start* of the golden era of Microbiology. The two main scientists that contributed a lot to this field were *Louis Pasteur* and *Robert Koch*. Louis Pasteur *disproved the spontaneous generation theory*, invented vaccines, gave the world a very important process called pasteurization. Robert Koch discovered disease-causing bacteria and created the *Koch postulates* which helped in establishing a *relationship between the microbes and infection*. Discovery of *agar* made growing bacteria in lab much easier. *Joseph Lister* used antiseptic for the first time. Development of microbiology led to development in various fields (such as genetics, immunology, medicine etc.)
Microfilaments
(ACTIN FILAMENTS) -Built from globular actin subunits -Involved in bearing tension and resisting pulling forces within the cell -Can interact with the motor protein myosin Actin and myosin interact to cause muscle contraction or amoeboid movement of white blood cells.
transient
(adj.) lasting only a short time, fleeting; (n.) one who stays only a short time
endemic
(adj.) native or confined to a particular region or people; characteristic of or prevalent in a field •Endemic disease: disease constantly present in a population.
sporadic
(adj.) occurring at irregular intervals, having no set plan or order •Sporadic disease: a disease that occurs only occasionally or seemingly randomly
duration
(n.) the length of time that something continues or lasts •Acute disease: symptoms develop rapidly but the disease lasts only a short time •Chronic disease: symptoms develop slowly •Subacute disease: intermediate between acute and chronic
Phase III: REGENERATION
(of the Calvin Cycle) 5 molecules of G3P are rearranged back into 3 molecules of RuBP. *This allows the process to begin again, creating a cycle. RuBP can accept the next CO2 (ATP --> ADP is required for these reactions)
Phase II: REDUCTION
(of the Calvin cycle) NADPH and ATP loose electrons - this REDUCES the molecules in the Calvin Cycle (NADPH --> NADP+ The electrons are used to transform six 3-PGA into six *Glyceraldehyde 3 phosphate* (G3P) One G3P exits the Calvin Cycle. (G3P contains more electrons, thus more potential enegry than 3-PGA)
phase I: CARBON FIXATION
(of the Calvin cycle) The initial incorporation of carbon from CO2 into organic compounds, specifically 3-PGA The enzyme RuBisCO (most abundant protein on Earth) adds CO2 to RuBP
second line of defense
* inflammatory response * elements of the blood * The Lymphatic System * phagocytosis * fever * The compliment system * interferons
animal life cycle
*Haploid* EGG SPERM Fertilization *Zygote* Mitosis Adults MALE FEMALE Meiosis EGG SPERM
Louis Pasteur (1822-1895)
*disproved* the *spontaneous generation* theory and invented *vaccines* and *pasteurization* demonstrated that spoilage bacteria could be killed by heat •Pasteurization: the application of high heat for a short time to kill harmful bacteria in beverages He realized that if germs were the cause of fermentation, then they might be a cause of diseases.
mRNA
*messenger* RNA carries the "message" from DNA to protein a large family of RNA molecules that convey genetic information from DNA to the ribosome, where they specify the amino acid sequence of the protein products of gene expression. The RNA polymerase enzyme transcribes genes into primary transcript mRNA (known as pre-mRNA) leading to processed, mature mRNA. This mature mRNA is then translated into a protein, as summarized in the central dogma of molecular biology. NITROGENOUS BASES: This molecule uses *uracil* instead of *thymine* to bond to *adenine*.
tRNA
*transfer* and *adaptor* RNA molecule; used in translation, consisting of a single RNA strand comprised of around 76-90 nucleotides contains an anticodon on an end; the anticodon base-pairs with a complementary codon on mRNA and is an adaptor molecule composed of RNA. serves as the physical link between the mRNA and the amino acid sequence of proteins because it carries an amino acid to the ribosome (protein synthetic machinery of the cell) *as directed by a codon (3-nucleotide sequence) in a messenger RNA (mRNA)*. a necessary component of translation, the biological synthesis of new proteins in accordance with the genetic code. (formerly referred to as sRNA, for soluble RNA)
Nucleolus
-Found inside the nucleus -synthesizes: Ribosomal RNA, rRNA proteins
Difference between free and bound ribosomes
-Free ribosomes: suspended in cytosol -Bound ribosomes: attached to ER or nuclear envelope
Eukaryotic cells
-Larger and more complex -nucleus -membrane bound organelles -DNA tightly wrapped around histone proteins in chromosomes -cellulose in plant cell walls.
nicotinamine adenine dinucleotide
-Oxidizing agent during respiration -Electron carrier -becomes reduced by gaining electrons (NAD+) NAD+ uses dehydrogenase(s) to remove a pair of hydrogen atoms (two electrons) from glucose. NAD+ only bonds with one of those hydrogen atoms.
5 Common features of all cells
-cell membrane -cytoplasm -ribosomes -DNA(chromosomes) -cytosol(semi-fluid substance)
Pigmentation
-color of the colony positive: any other color besides white or beige negative: no color (white/clear)
Cell junctions
-contact points between the plasma membranes of tissue cells -Types of cell junctions: Tight junctions Desmosomes Gap junctions
Food vacuoles
-formed by phagocytosis -pinches off from plasma membrane and encloses a food particle
Contractile vacuoles
-found in many freshwater protists -pump excess water out of cells
Central vacuoles
-found in most mature plant cells -stores organic compounds and water
Oxygen
-gains electrons by bonding with hydrogen -very electronegative (Carbon, Hydrogen, Oxygen, and Nitrogen are compositions of approximately 96% of living things.)
Endoplasmic Reticulum (ER)
-maze of passageways in which proteins and other materials are carried from one part of the cell to another. -possesses the nuclear envelope -Smooth/Rough endoplasmic reticulum: Smooth: no ribsomes Rough: studded with ribosomes -cisternae: tubules and sacs within the ER
Cytoskeleton
-network of fibers networked throughout the cytoplasm -Supports the cell and maintains its shape -Provides anchorage for many organelles and molecules -Interacts with motor proteins for motility -Vesicles and other organelles can "walk" along the tracks provided by the cytoskeleton
Rough Endoplasmic Reticulum
-presence of ribosomes -involved in secreted protein production -functions in transport of substances such as proteins within the cytoplasm
Meiosis
-sex cells -results in 4 cells with half their DNA; they are genetically different -combines with other sex cells or dies (except some plants)
Form
-shape of a colony
plant cell wall
-strong, protective structure made from cellulose fibrils -not present in animal cells
(8 Steps) light-dependent reactions
1 Light strikes a pigment molecule in the light harvesting complex of Photosystem II(PSII). The electrons of the pigments goes to higher energy level. AKA "exited") *Electron falls back down to ground state and stimulates the next pigment molecule nearby (this continues until the energy reaches the P680 reaction center) 2 Electron is transferred from P680 (reaction center) to the primary electron acceptor, cytochrome PQ. 3 An enzyme (of Photosystem II) splits a water molecule into 2 electrons. The water molecule becomes 2 H+ & oxygen* Electrons enter the reaction center(P680), where they are donated to primary electron acceptor. H+ released into thylakoid space; oxygen combines with an oxygen from the next split water molecule. 4 Electrons pass from PSII to PSI using an electron transport chain. *H+ are pumped into the thylakoid space, creating a gradient. 5 As the electrons "fall" down the electron transport chain, ATP is produced. 6 Light energy hits PSI and excites electrons that travel to P700. P700 then donates electrons to primary acceptor. *P700 accepts electrons coming in from the electron transport chain from PSII 7 Electrons are passed from primary acceptor in PSI down a 2nd electron transport chain. *No H+ gradient is present, so no ATP is produced. 8 *NADP+ reductase* takes 2 electrons and a H+ from the stroma to produce NADPH *Products are ATP and NADPH -Transfer of electrons down ETC from water rather than NADH/FADH2
DNA replication steps
1) *Helicase*, an enzyme, splits the parental double helix. This forms a *replication fork*, causing the double helix to split into two single strands. 2) *DNA topoisomerase* alleviate torsional strain. (tension of the DNA strands) 3) With the aid of *DNA gyrase*, single-strand binding proteins (SSBP) stabilize unwound DNA. 4) *Primase* synthesizes a short RNA *primer* for the *DNA polymerase* to bind to in the 5' to 3' direction, starting replication on each strand. >RNA primers are indicators for DNA polymerase to begin synthesizing DNA fragments. >3' and 5' denote different directions 5) DNA polymerase binds to an RNA primer and synthesizes DNA fragments on the *leading strand* from 5' to 3' direction. The *lagging strand* is made discontinuously by *primase*, making short pieces. Then DNA polymerase extends these fragments, creating *Okazaki fragments*. -The leading strand and the lagging strand are the single strands resulting from the replication fork. -DNA polymerase only synthesizes DNA fragments from the 5' to the 3' direction. 6) *DNA ligase* joins the Okazaki fragments together 7) *Exonucleas*, an enzyme, then removes the RNA primers. The resulting gaps are filled in with DNA polymerase I. 8) DNA ligase seals the fragments of DNA in both strands.
Virus Classification
1. Nucleic acid (size, type, structure) 2. replication strategy 3. capsid symmetry 4. presence of an envelope (+ or -) •The phylogeny of viruses is unclear, so they can't be classified in the same way as cellular organisms. •Different suffixes indicate taxonomic level, beginning with "Family" •"Species" name of pathogenic viruses is generally associated with the disease they cause 6 Orders -- names end in "virales" 94 Families -- names end in "viridae" 22 Subfamilies -- names end in "virinae" 395 Genera -- names end in "virus" 2,500 Species
what are the five steps in culturing microbes?
1. inoculation=introduction of sample into a container of sterile media to produce a culture of observable growth 2.incubation=under conditions that allow growth 3.isolation=separating the species from one another 4.inspection=macroscopically for color, texture, size, gas production; microscopically for cell shape, size and motility 5.identification=staining biochemically for metabolism, immunological or genetic
Thrombocytopenic purpura
1.) A drug, in the form of a hapten, is introduced to the body. 2.) Platelets (blood clotting) combine with the drug(s), forming a complex that is antigenic. 3.) The humoral immune response is activated 4.) The antibodies created by the humoral immune response binds to the molecules of the drugs; the antibodies also compliment-bind to each other, forming an attack complex 5.) The resulting membrane attack complexes of the compliment antibodies lyse the platelet cells.
citric acid cycle
1.) Coenzyme A delivers acetate to begin the Citric Acid Cycle 2.) Acetate bonds with oxaloacetate to form citrate (citrate is the first product) 3.) 2 CO2 molecules are released 4.) 1 ATP generated per "turn" of the cycle 5.) 3 NAD+ reduced to NADH FAD reduced to FADH2 (8 steps total)
Electron Transport Chain
1.) Electrons from the electron carriers, NADH & FADH2, are sent (from the citric acid cycle) through a series of molecules to create 32 ATP. NADH carries electrons from Citric Acid Cycle to Complex I FADH2 carries electrons from Citric Acid Cycle to Complex II -Exergonic reactions occur each step -electrons lose a small amount of energy per step until the bonding of oxygen occurs 2.) Cytochrome Q shuttles electrons from Complex I or II to Complex III 3.) Cytochrome C shuttles electrons from Complex III to Complex IV 4.) Electrons transferred from Complex IV to oxygen 5.) At the end of the chain the electrons will attach to hydrogen ions and oxygen atoms to form water. Oxygen + electrons + (2H+) = H2O
pyruvate oxidation
1.) Pyruvate (comprised of 3 carbons) enters the mitochondria. 2.) The pyruvate becomes acetate(comprised of 2 carbons). -The pyruvate loses a carbon, which becomes CO2, and a hydrogen, which bonds with NAD+. 3.) The acetate combines with coenzyme A to become acetyl coenzyme A(CoA). 4.) NAD+ reduces to NADH because of hydrogen(H) from the acetate. (NAD+ --> NADH) 5.) Acetyl CoA enters the Citric Acid Cycle.
Edward Jenner
1.) When he was a medical student, Jenner noticed that milkmaids who had contracted cowpox (a disease which causes blistering on cow's udders) did not catch smallpox. • Unlike smallpox, which caused severe skin eruptions and dangerous fevers in humans, cowpox led to few ill symptoms in these women. 2.) On May 14, 1796, Jenner took fluid from a cowpox blister and scratched it into the skin of James Phipps, an eight-year-old boy. A single blister rose up on the spot, but James soon recovered. On July 1, Jenner inoculated the boy again, this time with smallpox matter, and no disease developed. 3.) The vaccine was a success. Doctors all over Europe soon adopted Jenner's innovative technique, leading to a drastic decline in new sufferers of the devastating disease.
viral growth curve
1.) inoculation During the initial stage, an inoculum of virus causes infection. 2.) eclipse In the eclipse phase, viruses bind and penetrate the cells with no virions detected in the medium. 3.) burst The chief difference that next appears in the viral growth curve compared to a bacterial growth curve occurs when virions are released from the lysed host cell at the same time. Such an occurrence is called a burst. 4.) burst size The number of virions per bacterium released is described as the burst size. Unlike the growth curve for a bacterial population, the growth curve for a virus population over its life cycle does not follow a sigmoidal curve. In a one-step multiplication curve for bacteriophages, the host cells lyse, releasing many viral particles to the medium, which leads to a very steep rise in viral titer (the number of virions per unit volume). If no viable host cells remain, the viral particles begin to degrade during the decline of the culture.
Ultra High Temperature (UHT)
140 C for 4 sec
Eminent Figures of Germ Theory
1835: *Agostino Bassi* showed that a silkworm disease was caused by a fungus 1840s: *Ignaz Semmelweis* advocated hand-washing to prevent transmission of puerperal fever from one obstetrical patient to another 1860s: *Joseph Lister* Expanded on Pasteur's work by showing that microbes are in the air, can spoil food, and causes animal diseases. He used a chemical *antiseptic* (*phenol*) to prevent surgical wound infections. 1865: *Louis Pasteur* showed that another silkworm disease was caused by a protozoan 1876: *Robert Koch* discovered that a bacterium causes anthrax and provided experimental steps, known as Koch's postulates, to demonstrate that a specific microbe causes a specific disease
The Second Golden Age of Microbiology (1943-1970)
1943-1970 •focused on genetics of microorganisms •proposed DNA to be the genetic material rather than proteins *Beadle and Tatum* demonstrated that genes direct the synthesis of DNA. *Luria and Delbruck* used E. coli to show that mutations occur spontaneously. -Streptococcus pneumonia was used to suggest DNA is the genetic material. *Hershey and Chase* used a virus to confirm that DNA is the genetic material. Watson and *Crick* used E. coli and a virus to show how DNA is the genetic code necessary to create proteins.
Telophase I (Meiosis)
2 nuclei form and cytokinesis occurs, resulting in 2 haploid daughter cells each nuclei is now "n"
checkpoints
3 points where regulatory proteins (enzymes) determine if cell is ready to proceed in cell cycle *G1/Start checkpoint* (aka Restriction checkpoint) •most crucial• Some cells NEVER pass G1 checkpoint *G2 /M checkpoint* •determines if cell is really ready for M-phase *Meta-to-Ana checkpoint* •determines if cell ready for cytokinesis •triggers separation of sister chromatids
objectives
3/4 attachments for viewing specimen; 4x(scanning/low power), 10x high power, 40x, 100x oil immersion
end products of meiosis
4 haploid cells Males: All 4 haploid cells mature into sperm Females:Three of the 4 haploid cells "die" *1 survives to mature into an egg
Photosynthesis
6CO2 + 6H2O --> C6H12O6 + 6O2 performed using light reactions and the Calvin cycle
Products of cellular respiration
6CO2+ 6H2O + ATP carbon dioxide + water + energy
high temperature short time (HTST)
72 C for 15 sec
replication fork
A "Y-shaped" region on a replicating DNA molecule where two new strands originate and grow.
Cryptococcus neoformans
A Heavily encapsulated yeast found in soil and pigeon shit; acquired through inhalation. Stains with India ink and mucicarmine
Mutation
A change in a gene or chromosome In genes, this can cause faulty enzymes which can lead to an identifiable condition.
denature
A change in the shape of a protein- such as enzymes-that can be caused by changes in temperature or pH, among other things.
Citric Acid Cycle (Krebs Cycle)
A chemical cycle that completes the metabolic breakdown of the glucose molecules by oxidizing acetyl CoA (derived from pyruvate) to carbon dioxide -occurs within mitochondrion in eukaryotic cells -occurs in cytosol of prokaryotes -3rd step of cellular respiration
Mutagen
A chemical or physical agent that interacts with DNA and causes a mutation •Mutagens increase the mutation rate to 10^-5 or 10^-3 per replicated gene ENDOGENOUS: mutagens that come from within the body EMINENT EXAMPLES: > Reactive Oxygen Species: ENDOGENOUS: mutagens that are introduced from external sources from the body EMINENT EXAMPLES: > Intercalculators > Base Analogues > carcinogens Also things like poison, UV light, radiation, etc.
asthma
A chronic allergic disorder characterized by episodes of severe breathing difficulty, coughing, and wheezing
Basophils
A circulating granulocytes that produces histamine; works in the "early stages" of infection *this includes allergic responses (allergies)
Symbiosis
A close relationship between microbiota and the host in which at least one of the species benefits. •Commensalism: one organism benefits, and the other is unaffected. •Mutualism: both organisms benefit •Parasitism: one organism benefits at the expense of the other
Coenzyme A
A coenzyme that carries acetate from the link reaction of respiration to Krebs cycle.
lactam
A cyclic amide; named according to the number carbon atoms other than the carbonyl carbon
gastric juice
A digestive fluid secreted by the stomach •its low pH [ 1.2-3.0 ] destroys most bacteria and toxins
lagging strand
A discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5' to 3' direction away from the replication fork. DNA polymerase III moves away from the replication fork and consists of OKAZAKI FRAGMENTS, which are short discontinuous segments requires many RNA primers
Pandemic
A disease that occurs over a wide geographic area and affects a very high proportion of the population •Pandemic disease: nearly or totally a world-wide epidemic
Diplobacilli
A double bacillus, two being linked end to end to each other
Major Histocompatibility Complex (MHC)
A family of genes that encode a large set of cell surface proteins called MHC molecules. Class I and II MHC molecules function in antigen presentation to T cells. CLASS I MHC MOLECULES Class I MHC genes encode glycoproteins expressed on the surface of nearly all nucleated cells; the major function of the class I gene product is presentation of peptide antigens to TC cells. • found on the membrane of nucleated animal cells • Identify "self" CLASS II MHC MOLECULES Class II MHC genes encode glycoproteins expressed primarily on APCs, where they present processed antigenic peptides to TH cells. • located on the surface of antigen-presenting cells (APCs), including B cells TRANSPLANTS Foreign MHC molecules on transplanted tissue can trigger T cell responses that may lead to rejection of the transplant.
Keratin
A fiber protein that is the principal component of hair, skin, and nails; provides structure
Thylakoid
A flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy.
binary fission
A form of asexual reproduction in single-celled organisms by which one cell divides into two smaller cells, then each daughter cell regenerates into full-sized cells. the division of a single entity into two or more parts and the regeneration of those parts to separate entities resembling the original.
Budding
A form of asexual reproduction of yeast in which a new cell grows out of the body of a parent
Agranulocytes
A group of leukocytes lacking granules in their cytoplasm that are visible with a light microscope * MONOCYTES * DENDRITIC CELLS * LYMPHOCYTES COMPARE Granulocytes and agranulocytes are the two types of white blood cells or leukocytes. Granulocytes contain granules or sacs in their cytoplasm but agranulocytes don't.
clades
A group of species that includes an ancestral species and all its descendants.
Granulocytes
A group of white blood cells (leukocytes) containing secretory granules in their cytoplasm: * neutrophils * eosinophils * basophils These granules are visible with a light microscope. COMPARE Granulocytes and agranulocytes are the two types of white blood cells or leukocytes. Granulocytes contain granules or sacs in their cytoplasm but agranulocytes don't.
Microtubules
A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella. FUNCTIONS Shape and support the cell Guide movement of organelles Separate chromosomes during cell division organized as nine pairs in a ring, plus two microtubules in the center •allow flagella to move in a "wave-like" manner
cytoplasm
A jellylike fluid inside the cell in which the organelles are suspended •The substance inside the plasma membrane •Eighty percent water plus proteins, carbohydrates, lipids, and ions •Cytoskeleton (a series of fibers like small roads and cylinders)
cytoplasm
A jellylike fluid inside the cell in which the organelles are suspended; substance inside the plasma and outside the nucleus •Cytosol: fluid portion of cytoplasm •Cytoskeleton: made of microfilaments and intermediate filaments; gives shape and support •Cytoplasmic streaming: movement of the cytoplasm throughout a cell
CDKs (cyclin-dependent kinases)
A kinase whose activity depends on the level of cyclins. This controls the timing of cell division. Cells rely on Cdks & cyclin to bypass *checkpoints*. Vertebrates possess 4 Cdks •If no cyclin is present, the CdK remains inactive
PCR (polymerase chain reaction)
A laboratory technique designed to amplifying (makes a small fragment much larger, to study easier) DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides Typically, the goal is to make enough of the target DNA region that it can be analyzed or used in some other way. For instance, DNA amplified by PCR may be sent for sequencing, visualized by gel electrophoresis, or cloned into a plasmid for further experiments.
PCR (polymerase chain reaction)
A laboratory technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides involves nucleic acids, specifically DNA and mRNA. This method greatly exemplifies a strand of DNA, making enough to study in detail. A DNA double helix is separated and primers bind to the complementary sequences, synthesizing DNA. This process continues until the original DNA template is amplified to a great number of strands. EXAMPLE Covid-19 (lol) is a RNA virus but PCR is still a viable method for detecting it. The Reverse transcriptase enzyme can convert its RNA to DNA. PCR can be much faster than a Western blot. Western blot can be a good method to confirm virus infection like HIV also.
bleb
A large flaccid vesicle of cells caused by blebbing • Most commonly, a result of apoptosis (programmed cell death)
Polypeptide
A linear organic polymer chain of many amino acids linked together by peptide bonds, forming part or all of a protein molecule.
DNA ligase
A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain. seals then joins the Okazaki fragments to the continuous DNA strand.
Epididymis
A long, coiled duct on the outside of the testis in which sperm mature.
temperature
A measure of how hot something is; the average kinetic energy of the particles in an object RANGE •Minimum growth temperature •Optimum growth temperature •Maximum growth temperature
Glycolysis
A metabolic process taking place in the cytoplasm that breaks down carbohydrates and sugars through a series of reactions PRODUCTION either pyruvic acid or lactic acid is produced and energy is released in the form of ATP •2 NADH are produced •The oxidation of glucose to pyruvic acid produces ATP and NADH •Preparatory, energy-conserving stage •2 ATP is required, 4 ATP are produced OVERVIEW 1.) Glucose is split to form two molecules of glyceraldehyde 3-phosphate 2.) The two glyceraldehyde 3-phosphate molecules are oxidized to form 2 pyruvic acid molecules Glucose + 2 ATP + 2 ADP + 2 (PO4-) + (2 NAD+) = 2 pyruvic acid + 4 ATP + 2 NADH + (2H+) •Overall net gain of two molecules of ATP for each molecule of glucose oxidized
Gram Stain
A method for the differential staining of bacteria that involves fixing the bacterial cells to a slide and staining with crystal violet and iodine, then washing with alcohol, and counterstaining with safranin. Results in gram-positive bacteria retaining the purple dye and gram-negative organisms having it decolorized so that the red counterstain shows up. Clear after heat fixation Both cells take up dye Forms crystal violet/iodine complex Ethanol removes lipid layer in Gram-negative and tightens wall in Gram-positive (crystal violet remains in Gr positive but washed out in Gram-negative) Safranin stains Gram-negative.
replica plating
A method of determining the genotypes of colonies by identifying the colonies that have certain mutations via selective media. This process involves the transferring of cells from each colony on a master plate to secondary (replica) plates and observing their growth when exposed to different conditions. 1.) The master plate is the initial plate of agar that contains all the colonies. 2.) A velveteen, which is like a special covering, is placed on the master plate and pressure is applied on it so that the colonies are transferred onto it. 3.) The velveteen is pressed on other new plates so that the colonies grow again. These new plates differ in such a way that the growth of the colonies is affected by each plate. Ideally, the mutants are encouraged to grow while the "normal" microbes aren't.
feedback inhibition
A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway. (This process ends itself )
Transmission Electron Microscope (TEM)
A microscope that uses an *electron* beam which passess through *thin*ly sectioned specimens in order to reveal their *internal structure*. (50x to *1,000,000x*) magnification
rubella (German measles; 3-day measles)
A mild febrile (fever-causing) infectious disease caused by a virus resembling both scarlet fever and measles but differing from these in its short course • characterized by a rash of both macules and papules that fades and disappears in three days.
suspension
A mixture in which particles can be seen and easily separated by settling or filtration If taking bacteria from media, use small drop of DI H2O to make suspension of bacteria. Remember sterile techniques ◦flame inoculating loop before and after use ◦Do not touch sides of tube or plate ◦Do not lay cap on table ◦Do not lay lid of petri dish on table ◦Flame tubes before and after entry
silent mutation
A mutation that changes a single nucleotide, but does not change the amino acid created.
Nonsense mutation
A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.
Acetylcholine
A neurotransmitter that enables learning and memory and also triggers muscle contraction
chlorophyll a
A photosynthetic pigment that participates directly in the light reactions. (converts solar energy to chemical energy) -only pigment able to directly convert photons to chemical energy
missense mutation
A point mutation in which a codon that specifies an amino acid is mutated into a codon that specifies a different amino acid. >This changes the amino acid sequence. This mutation may or may not cause problems
cytokine storm (hypercytokinemia)
A potentially fatal immune reaction caused by highly elevated levels of various cytokines Cytokines play an important role in normal immune responses, but having a large amount of them released in the body all at once can be harmful. CAUSE can occur as a result of an infection, autoimmune condition, or other disease. It may also occur after treatment with some types of immunotherapy. EFFECT Signs and symptoms include high fever, inflammation (redness and swelling), and severe fatigue and nausea. Sometimes, a cytokine storm may be severe or life threatening and lead to multiple organ failure.
vacccine
A preparation of antigens administered to the human body to provide artificial immunity • produces a rapid, intense secondary response TYPES - killed, whole cell or inactivated viruses - Live, attenuated cells or viruses - Antigenic molecules from bacteria or viruses - Genetically engineered microbes or microbial antigens (a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies) HISTORY • Jenner inoculated people with cowpox so that they would be immune to smallpox. • This term was created by Louis Pasteur; vacca" means cow
Chemiosmosis
A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme Electrons (from NADH) pass down the electron transport chain while protons are pumped across the membrane •Establishes proton gradient (proton motive force) Protons in higher concentration on one side of the membrane diffuse through ATP synthase •Releases energy to synthesize ATP
chemiosmosis
A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.
Chemiosmosis
A process for synthesizing ATP using the energy of an electrochemical gradient, hydrogen, and the ATP synthase enzyme Uses the high concentration of H+ in the intermembrane space of mitochondria to drive the work needed to make ATP -chemical ions move from high to low concentration H+ bind to the rotor on ATP synthase causing it to rotate rotation promotes ADP joining to P to make ATP
natural selection
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits; ensures the survival of organisms fit for a particular environment
Filtration
A process that separates materials based on the size of their particles •Solution passed through a filter that collects bacteria •Filter is transferred to a Petri dish and grows as colonies on the surface
TATA box
A promoter DNA sequence crucial in forming the transcription initiation complex. This sequence makes up most of the *promoter site* and helps the start site of *transcription*. T represents thymine A represents adenine The TATA box lies 25 base pairs to the left, or "upstream" from the *start point* > *Transcription factors* recognize the TATA box and bind to it before the RNA polymerase does."
antibody
A protein that acts against a specific antigen
repressor
A protein that suppresses the transcription of a gene by binding to a repressible operon. The polymerase doesn't synthesize a new segment of DNA (transcription) because its path on the template strand is obstructed by the repressed operon.
Antigen
A protein that, when introduced in the blood, triggers the production of an antibody
antigen
A protein that, when introduced in the blood, triggers the production of an antibody •Pathogens can alter their surface antigens so that antibodies are rendered ineffective.
Glycoproteins
A protein with one or more covalently attached carbohydrates.
peptidoglycan
A protein-carbohydrate compound that makes the cell walls of bacteria rigid
peptidoglycan
A protein-carbohydrate compound that makes the cell walls of bacteria rigid Polymer of a repeating disaccharide in rows: •N-acetylglucosamine (NAG) •N-acetylmuramic acid (NAM) Rows are linked by polypeptides
Memory (anamnestic) (secondary) response
A rapid rise in antibody titer following exposure to an antigen after the primary response to that antigen Memory cells are vital in triggering this response, which occurs after a second exposure to an antigen. The memory cells from the initial encounter are activated, causing the immune system compared to the initial encounter to be stronger and quicker against the specific pathogen. • This "memory" lasts many days.
Commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected
parasitism
A relationship between two organisms of different species where one benefits and the other is harmed
Mutualism
A relationship between two species in which both species benefit
cell wall
A rigid layer of nonliving material that surrounds the cells of plants and some other organisms •Prevents osmotic lysis (bust) and protects the cell membrane •Made of peptidoglycan (in bacteria) •Contributes to pathogenicity
Gene
A segment of DNA on a chromosome that codes for a specific trait-usually proteins
Electron transport chain
A sequence of electron carrier molecules (Cytochromes) that shuttle electrons during the redox reactions that release energy used to make ATP. a collection of membrane-embedded proteins and organic molecules, most of them organized into four large complexes. In eukaryotes, many copies of these molecules are found in the inner mitochondrial membrane. In prokaryotes, the electron transport chain components are found in the plasma membrane. •Aerobic Respiration •Occurs in the plasma membrane of prokaryotes; inner mitochondrial membrane of eukaryotes •Series of carrier molecules: flavoproteins cytochromes ubiquinones are oxidized and reduced as electrons are passed down the chain •Energy released is used to produce ATP by chemiosmosis •The final electron acceptor in the electron transport chain is molecular oxygen (O2)
plasmid
A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome (module) •can carry genes for toxins, production of antibiotics, and enzymes
lawn of bacteria
A solid growth of bacteria converging an entire surface of growth agar in a petri dish
isotonic solution
A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution
hypertonic solution
A solution in which the concentration of solutes is greater than that of the cell that resides in the solution; the cell shrivels because water, the solvent, is attracted to the solution outside of the cell.
hypotonic solution
A solution in which the concentration of solutes is less than that of the cell that resides in the solution; water, the solvent, enters the cell. Lysis occurs on animal cells, meaning they burst. But not plant cells, because the cell wall can withstand more turgor pressure.
tincture
A solution where a solute is dissolved into alcohol
allosteric site
A specific receptor site on an enzyme; not near the active site. non-competitive inhibitors may bind to this site, causing a change in the shape of the enzyme and influencing its ability to be active. This process is called allosteric inhibition
Codon
A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic information for a particular amino acid. QUESTION How can 4 nucleotides encode for *the 20 amino acids*? (They can't be one-to-one.) ANSWER *Codons consist of three nucleotides in a sequence.* *Some codons code for the same amino acid.* (4^3<20) (4^3=64) (64>20)
inducer
A specific small molecule that deactivates the repressor in an operon by binding to an inducible operon. COMMON SCENARIO •In the absence of lactose, the repressor binds to the operator, preventing transcription. •In the presence of lactose, lactose (which is an inducer) binds to the repressor; the repressor subsequently changes shape when lactose is bound to it and can't bind to the operator. Because of this, transcription can now occur.
Granum
A stack of thylakoids in a chloroplast
Gram stain
A staining method that distinguishes between two different kinds of bacterial cell walls GRAM NEGATIVE: cell walls are composed of thick layers of peptidoglycan GRAM POSITIVE: cell walls with a thin layer of peptidoglycan 1. innoculate bacteria by smearing 2. air dry 3. heat fix 4. gram crystal violet 5. wait a minute 6. rinse with water 7. gram Lugol's iodine 8. wait one minute 9. rinse with water 10. add drops of 95% ethyl alcohol until no more purple rinses off 11. rinse with water 12. safranin 13. wait 14. rinse 15. dry (use bibulous paper) 16. examine
starch
A storage polysaccharide in plants consisting entirely of glucose. (long-term energy storage)
Starch
A storage polysaccharide in plants consisting entirely of glucose. hydrolyzes into glucose
Chitin
A structural polysaccharide, consisting of amino sugar monomers-found in many fungal cell walls and in the exoskeletons of all arthropods-that provides both toughness and flexibility.
Human Microbiome Project
A study of the relationships between the human microbiome and the human body and its impact on healthiness. Human Microbiome: the collection of all the microorganisms living in association with the human body.
Biofilm
A surface-coating colony of one or more species of prokaryotes that engage in metabolic cooperation •Microbial communities •Form slime or hydrogels that adhere to surfaces •Bacteria communicate cell-to-cell via quorum sensing •Share nutrients •Shelter bacteria from harmful environmental factors •Found in digestive system and sewage treatment systems; can clog pipes •1000x resistant to microbicides •Involved in 70% of infections (catheters, heart valves, contact lenses, dental caries) comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPS). The cells within the biofilm produce the EPS components, which are typically a polymeric conglomeration of: > extracellular polysaccharides > proteins > lipids > DNA. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes".
Golgi apparatus (Golgi complex)
A system of membranes that modifies and packages proteins for export out of the cell. •Transports organelle(s) •Modifies proteins from the ER •Transports modified proteins via secretory vesicles to the plasma membrane -"shipping and receiving" -ships products via transport vesicles Vacuoles are cavities in the cell formed from the Golgi complex which bring food into cells and provides shape and storage.
enzyme-substrate complex
A temporary complex formed when an enzyme binds to its substrate molecule(s) •Substrates are transformed and rearranged into products, which are released from the enzyme •Enzymes remain unchanged during the reaction and can react with other substrates
Conjugation
A temporary union of two organisms for the purpose of DNA transfer; plasmids are transferred from one bacterium to another •Requires cell-to-cell contact via sex pili
endospores
A thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions •Resting cells; produced when nutrients are depleted •Resistant to desiccation, heat, chemicals, and radiation •Produced by Bacillus and Clostridium Sporulation: endospore formation Germination: endospore returns to vegetative state
glyceraldehyde 3-phosphate
A three-carbon carbohydrate that is the direct product of the Calvin cycle; it is also an intermediate in glycolysis. G3P *used to create sucrose and starch
virus
A tiny substance that act as a "piece of code"; invades and then reproduces inside a living cell. "viral" typically has a detrimental effect, such as corrupting the system or destroying data
virus
A tiny, nonliving particle that invades and then reproduces inside a living cell; much smaller than bacteria Viruses are composed of the head and the tail. ANATOMY HEAD capsid: contains the nucleic acid (singe or double-stranded DNA and/or single or double-stranded RNA). The capsid can appear as two main forms: helical or Icosahedral. spikes: protrude from the capsid; they are capable of membrane fusion, attaching onto the membrane of a foreign microbe and manipulating the membrane in such a way that the virus can inject its compounds into it. TAIL sheath plug tails (fibers) TYPES of virus Animal virus Bacteriophages
Endotoxin
A toxic component of the outer membrane of certain gram-negative bacteria that is released only when the bacteria die
Aquaporins
A transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across the membrane
Lymphocytes
A type of agranular white blood cell (leukocyte) that make antibodies to fight off infections; plays a role in adaptive immunity TYPES T cells B cells NK cells
Missense mutation
A type of base-pair substitution (point mutation) that results in a codon that codes for a different amino acid
Sterols
A type of lipid based on cholesterol; includes testosterone and estrogen. compounds containing a four-ring carbon structure with any of a variety of side chains attached
Cytotoxic T cells
A type of lymphocyte that kills infected body cells and cancer cells; destroys pathogens and releases cytokines recognize and kill the body's own cells if they are infected or cancerous by releasing perforin and granzymes that induce apoptosis in the infected cell. The cells of the body possess endogenous antigens that connect to MHC class I molecules.
chlorophyll b
A type of yellow-green accessory photosynthetic pigment that transfers energy to chlorophyll a (It helps increase the range of light a plant can use for energy)
provirus
A viral genome that is permanently inserted into a host genome
plaque
A viral plaque is a visible structure formed within a cell culture, such as bacterial cultures within some nutrient medium (e.g. agar). The bacteriophage viruses replicate and spread, thus generating regions of cell destructions known as plaques.
epidemic
A widespread outbreak of an infectious disease •Epidemic disease: disease acquired by many people in a given area in a short time.
start codon
AUG (methionine); codon that signals to ribosomes to begin translation. codes for the first amino acid in a protein
Asepsis
Absence of pathogens or significant contamination
Carotenoids
Accessory pigments that broaden the spectrum of colors that can drive photosynthesis. -absorb light in wavelengths that chlorophyll can't -divert excess energy away from chlorophyll molecules (prevents overloading the system)
taxonomic hierarchy
All organisms can be grouped into a series of subdivisions Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species MNEMONIC "King Philip Came Over For Gold and Silver"
Quaternary ammonium compounds
Also known as quats; disinfectants that are very effective when used properly in the salon
polyenes
Amphotericin B Nystatin
disease
An abnormal state in which the body doesn't function normally
Monocytes
An agranular leukocyte that is able to migrate into tissues and transform into a macrophage; they become phagocytic
NADPH
An electron carrier involved in photosynthesis. Light drives electrons from chlorophyll to NADP+, forming NADPH, an electron carrier which provides the high-energy electrons for the reduction of carbon dioxide to sugar in the Calvin cycle.
FADH2
An electron carrier molecule produced during the Krebs cycle that stores energy for the electron transport chain the reduced form of flavin adenine dinucleotide •Assist enzymes; electron carrier •each molecule can produce 2 molecules of ATP
lipid A
An endotoxin and the lipid component of lipopolysaccharides (LPS); which is released from dead Gram-negative bacteria. This can trigger shock and other symptoms in human hosts •Released during bacterial multiplication and when gram-negative bacteria die •Stimulate macrophages to release cytokines •Cause disseminated intravascular coagulation
Dehydrogenase
An enzyme that catalyzes a chemical reaction during which one or more hydrogen atoms are removed from a molecule.
Primase
An enzyme that joins RNA nucleotides to make the RNA *primer* using the parental DNA strand as a template.
reductase
An enzyme that promotes the chemical reduction of a specified substance.
Helicase
An enzyme that untwists the double helix of DNA at the replication forks.
Glycogen
An extensively branched glucose storage polysaccharide found in the liver and muscle of animals. (the animal equivalent of starch) hydrolyzes into glucose between meals
opsonization
An immune response in which the binding of antibodies to the surface of a microbe facilitates phagocytosis of the the microbe by a macrophage occurs when serum proteins are modified (by splitting apart, usually) via antibodies and factors. Cascading effect occurs; chain reaction Classical or Alternative Pathway •Promotes attachment of a phagocyte to a microbe
Zoonosis
An infectious disease that is transmissible from animals to humans zoonotic: (adj) disease capable of being transmitted from animals to humans zoonose: (noun) a zoonotic disease
spectrophotometer
An instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution
Cytochromes
An iron-containing protein and component of electron transport chains in the mitochondria/chloroplasts of eukaryotic cells and the plasma membranes of prokaryotic cells
secondary oocyte
An oocyte in which the first meiotic division is completed. The second meiotic division usually stops short of completion unless fertilization occurs. affiliated with *first polar body* The secondary oocyte remains in meiosis II until fertilization
Chloroplast
An organelle found in plant and algae cells where photosynthesis occurs. -Contain chlorophyll (green), enzymes, and other molecules that function in photosynthesis Chloroplast structure includes: Thylakoids: contains chlorophyll; membranous sacs, stacked to form a granum Stroma: the internal fluid
nitrogenous base
An organic base that contains nitrogen, such as a purine or pyrimidine; a subunit of a nucleotide in DNA and RNA A molecule found in DNA and RNA that encodes genetic information in cells.
embryo
An organism in the earliest stage of development The terms embryonated, unembryonated and de-embryonated respectively mean "having an embryo", "not having an embryo", and "having lost an embryo", and they most often refer to eggs.
Haploid
An organism or cell possessing one complete set of chromosomes. •haploid cells formed during meiosis •Human haploids possess 23 chromosomes
Pathogen
An organism that causes disease
Photoheterotrophs
An organism that uses light to generate ATP but that must obtain carbon in organic form organisms that use light for energy, but cannot use carbon dioxide as their sole carbon source
Phenotype
An organism's physical appearance, or visible traits; observable with the naked eye
Helminths (worms)
Animals-multicellular eukaryotes that can be free living or parasites; Parasites can infect humans; Flatworms and roundworms PATHOGENIC PROPERTIES • Use host tissue for growth • Produce large masses; cause cellular damage • Produce waste products that can cause disease and pain
Penicillin
Antibiotic drug that combats bacteria by interfering with bacterial cell-wall synthesis
Pili
Appendages that allow bacteria to attach to each other and to transfer DNA •Involved in motility (gliding and twitching motility) •Conjugation pili involved in DNA transfer from one cell to another
Icosahedral viruses
Are polyhedral with 20 identical triangular faces Have a structure that exhibits rotational symmetry
Refrigeration
Artificial cooling that drastically reduces the microbial growth of certain bacteria. 40° F or less
Thymic selection
As T-cells are created and mature, the body acts as a selective filter by killing (apoptosis) the T-cells that aren't able to bind to epithelial MHC molecules. This is because the TLR (Toll-like receptors) of T-cells must be able to bind to MHC molecules in order to stop infections. The surviving T-cells will go on to proliferate (reproduce). • Positive selection The T-cells are able to strongly bind to Class I and Class II MHC molecules of epithelial cells. They are subsequently spared and are allowed to mature and proliferate. • Negative selection The T-cells aren't able to bind to or only weakly bind to the Class I and Class II MHC molecules. They are subsequently killed and don't proliferate.
Atypical Cell Walls
Atypical bacteria are bacteria that do not color with gram-staining but rather remain colorless: they are neither Gram-positive nor Gram-negative. Acid-fast cell walls •similar to gram-positive cell walls •Waxy lipid (mycolic acid) bound to peptidoglycan •Mycobacterium •Nocardia •Stain with carbolfuchsin Mycoplasmas •Lack cell walls •Sterols in plasma membrane Archaea •Wall-less, or •Walls of pseudomurein (lack NAM and D-amino acids)
prokaryotic domains
Bacteria and Archaea
Gram-positive bacteria
Bacteria possessing simple cell walls comprised of much peptidoglycan.
Gram-negative bacteria
Bacteria that have complex cell walls with lipopolysaccharides but little peptidoglycan *very toxic and hard to treat
Microbial exponential death rate
Bacterial populations usually die at a predictable, exponential rate when heated or treated with antimicrobial chemicals.
hematopoietic stem cells
Bone marrow cells can transform into or give rise to many types of blood cells
Epidemiology
Branch of medical science concerned with the incidence, distribution, and control of diseases; especially those that affect large numbers of people •The study of where and when diseases occur and how they are transmitted in populations Epidemiologists •Determine etiology of a disease •Identify other important factors concerning the spread of disease •Develop methods for controlling a disease •Assemble data and graphs to outline the incidence of disease
Glucose (sugar)
C6H12O6
cellular respiration
C6H12O6+6O2---> 6CO2+6H2O+ATP oxidation reaction in which glucose is oxidized and oxygen is reduced
Reactants of cellular respiration
C6H12O6+O6 glucose + oxygen
CAM Photosynthesis (Crassulacean Acid Metabolism)
CO2 is converted to 4-carbon molecule. Stomata opens in a dark enviornment (night) and cooler, more humid temperatures. -Carbon fixation takes place at night to reduce rate of water loss during CO2 uptake. example: desert plants (i.e. cactus)
cell wall
COMPONENTS •M protein: resists phagocytosis •Opa protein: allows attachment to host cells •Waxy lipid (mycolic acid): resists digestion
Chemical requirements for microbial growth
Carbon, Nitrogen, Sulfur, Phosphorus Carbon •Structural backbone of organic molecules •Chemoheterotrophs use organic molecules as energy •Autotrophs fix CO2 for carbon Nitrogen •Component of proteins, DNA, and ATP •Most bacteria decompose protein material for the nitrogen source •Some bacteria use NH4+ or NO3- from organic material •A few bacteria use N2 in nitrogen fixation Sulfur •Used in amino acids, thiamine, and biotin •Most bacteria decompose protein for the sulfur source •Some bacteria use SO42- or H2S Phosphorous •Used in DNA, RNA, and ATP •Found in membranes • PO43- is a source of phosphorus
Fahrenheit to Celsius
Celcius = (Fahrenheit - 32) (5/9)
Interphase
Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases
chemotaxis
Cell movement that occurs in response to chemical stimulus •Chemical signals attract phagocytes to microorganisms
CD4+ helper T cells
Cells that protect against infections and activate the body's immune response. • HIV kills these cells, so a high count usually indicates better health
mast cells
Cells that release chemicals (such as histamine) that promote inflammation
mast cells
Cells that release chemicals (such as histamine) that promote inflammation a migrant cell of connective tissue that contains many granules rich in histamine and heparin; a type of granulocyte derived from the myeloid stem cell that is a part of the immune and neuroimmune systems. •Inflammation: Activated complement proteins bind to mast cells, releasing histamine
CDC
Centers for Disease Control and Prevention •Collects and analyzes epidemiological information in the United States •Publishes Morbidity and Mortality Weekly Report (MMWR) •Morbidity: incidence of a specific notifiable disease •Mortality: deaths from notifiable diseases •Notifiable infectious diseases: diseases in which physicians are required to report occurrence •Morbidity rate: number of people affected in relation to the total population in a given time period •Mortality rate: number of deaths from a disease in relation to the population in a given time
Histamine
Chemical stored in mast cells that triggers dilation and increased permeability of capillaries; responsible for the symptoms of an allergy
Prophase
Chromosomes become visible, nuclear envelop dissolves, spindle forms Centrioles replicate, begin forming spindle fibers, and move to opposite poles of the cell. Chromatin condenses into chromosomes. The chromosomes migrate, attaching to *kinetochore microtubules*(component of the spindles from the centrioles) The nucleoli disappears.
Classification vs Identification
Classification: placing organisms in groups of related species •Lists of characteristics of known organisms Identification: matching characteristics of an unknown organism to lists of known organisms •Clinical lab identification
Chromatin
Clusters of DNA, RNA, and proteins in the nucleus of a cell
Chromatin
Clusters of DNA, RNA, and proteins in the nucleus of a cell. Chromatin is compacted into chromosomes when the cell begins to divide.
Exons
Coding segments of eukaryotic DNA.
Plasmolysis
Collapse and shriveling of a walled cell's cytoplasm due to a lack of water; the water exits the cell because of a higher concentration of solutes outside of the cell.
transcription factors (TF)
Collection of proteins that bind with RNA polymerase, creating an initiation complex. This signals the initiation of transcription. The TFs travel along DNA strands until they find the TATA box. They stop there. Note that the TATA box is a sequence of genes (composed only of thymines and adenines) located shortly behind the start point. Also note that the region comprising the TATA BOX + TFs, the start point, and all the nitrogenous bases in between them is called the promoter site.
snRNPs (small nuclear ribonucleoproteins)
Complexes of proteins and snRNA molecules (special, short types of RNA) that function as components of spliceosomes during splicing (the removal of introns from pre-mRNAs).
lymphatic system
Composed of a network of vessels, ducts, nodes, and organs meant to provides defense against infection •Contains lymphocytes and phagocytic cells •Lymph carries microbes to lymph nodes where lymphocytes and macrophages destroy the pathogen COMPONENTS * Lymph * lymphatic vessels * lymphoid tissue * red bone marrow
blood
Connective tissue consisting of plasma, erythrocytes, leukocytes, and platelets PRODUCTION Red blood cells, most white blood cells, and platelets are produced in the bone marrow, the soft fatty tissue inside bone cavities. Two types of white blood cells, T and B cells (lymphocytes), are also produced in the lymph nodes and spleen, and T cells are produced and mature in the thymus gland.
antibiotic safety
Consider these things when using antibiotics: • the Therapeutic index (risk versus benefit) • the reactions of antibiotics with other drugs • potential damage to organs (including risk to a fetus)
Peroxisomes
Contain oxidase enzymes that detoxify alcohol, hydrogen peroxide, and other harmful chemicals. •Oxidizes fatty acids; destroy H2O2 -Single-membraned structure -Produces hydrogen peroxide and then convert it to water -Example: Liver peroxisomes detoxify alcohol by transferring hydrogen from the poisons to oxygen to make water
Halogens
Contains nonmetals, 7 valence electrons in it's outermost energy level. Very reactive Iodine Tincture: solution in aqueous alcohol Iodophor: combined with organic molecules •Impairs protein synthesis and alters membranes Chlorine •Oxidizing agents; shut down cellular enzyme systems •Bleach: hypochlorous acid (HOCl) •Chloramine: chlorine + ammonia
infection
Contamination or invasion of body tissue by pathogens
Photosynthesis
Conversion of light energy from the sun into chemical energy •Light-dependent reactions conversion of light energy into chemical energy (ATP and NADPH) •Light-independent reactions ATP and NADPH are used to reduce CO2 to sugar (carbon fixation) via the Calvin-Benson cycle oxygenic 6CO2 + 12H2O + light energy = C6H12O6 + 6H2O + 6O2
India ink stain
Cryptococcus neoformans; can be used to determine if a cell has a gelatinous capsule
Viral Identification
Cytopathic effects a visible effect on a host cell, caused by a virus, that may result in host cell damage or death Serological tests •Western blotting: the reaction of the virus via antibodies Nucleic acids •RFLPs (restriction fragment length polymorphisms) •PCR (polymerase chain reaction)
Inclusions (reserve deposits)
Cytoplasmic inclusions are diverse intracellular non-living substances that are not bound by membranes. Inclusions are stored nutrients, secretory products, and pigment granules. Examples of inclusions are glycogen granules in the liver and muscle cells, lipid droplets in fat cells, pigment granules in certain cells of skin and hair, and crystals of various types. Cytoplasmic inclusions are an example of a biomolecular condensate arising by liquid-solid, liquid-gel or liquid-liquid phase separation. Metachromatic granules (volutin) phosphate reserves Polysaccharide granules energy reserves Lipid inclusions energy reserves Sulfur granules energy reserves Carboxysomes RuBisCO enzyme for CO2 fixation during photosynthesis Gas vacuoles protein-covered cylinders that maintain buoyancy Magnetosomes iron oxide inclusions; destroy H2O2
Naked DNA
DNA in prokaryotes that isn't associated with histones or histone-like proteins.
transduction
DNA is transferred from one cell to another through a medium such as a virus or, for bacteria specifically, a bacteriophage. •Generalized transduction: Random bacterial DNA is packaged inside a phage and transferred to a recipient cell. •Specialized transduction: Specific bacterial genes are packaged inside a phage and transferred to a recipient cell. 1. Phage injects DNA 2. Phage enzyme breaks down host DNA 3-4. Cell creates new phages, including phage and host DNA 5-6. Transducing phage Inserts donor DNA 7. Donor DNA included in recipients chromosome due to recombination
double strand break
Damage that results in breaks in both complementary strands of DNA; a DNA break cleaves the sugar-phosphate backbones of both strands of the DNA double helix
alcohol
Denatures proteins and dissolves lipids •No effect on endospores and nonenveloped viruses Ethanol and isopropanol •Denaturation requires water
gram positive
Describing the group of bacteria that have a cell wall that is structurally less complex and contains more peptidoglycan than the cell wall of gram-negative bacteria. Gram-positive bacteria are usually less toxic than gram-negative bacteria •Thick peptidoglycan •Teichoic acids stains purple in tests
gram negative
Describing the group of bacteria that have a cell wall that is structurally more complex and contains less peptidoglycan than the cell wall of gram-positive bacteria. Gram-negative bacteria are often more toxic than gram-positive bacteria. stains pink/red in tests •Periplasm between the outer membrane and the plasma membrane contains peptidoglycan •Outer membrane made of polysaccharides, lipoproteins, and phospholipids •Protect from phagocytes, complement, and antibiotics •Made of lipopolysaccharide (LPS) •O polysaccharide functions as an antigen (e.g., E. coli O157:H7) •Lipid A is an endotoxin embedded in the top layer •Porins (proteins) form channels through the membrane •Thin peptidoglycan •Outer membrane •Periplasmic space •4-rings in basal body of flagella •Produce endotoxins and exotoxins •Low susceptibility to penicillin because of the outer membrane
Osmosis
Diffusion of water through a selectively permeable membrane; a form of passive transport •the movement of water across a selectively permeable membrane from an area of high water to an area of lower water concentration •via lipid layer(s) •Aquaporins (water channels)
Hyporeactive
Diminished or reduced response
sporophyte
Diploid, or spore-producing, phase of an organism
sanitation
Disposal of waste products lowering microbial counts from eating utensils to safe levels
Archaea
Domain of unicellular prokaryotes that have cell walls that do not contain peptidoglycan TYPES Halophiles "salt-loving"; lives in environments with high levels of salt. They have been identified in the Great Salt Lake in Utah and in the Dead Sea between Israel and Jordan, which have salt concentrations several times that of the oceans. Thermophiles live in extremely hot environments. For example, they can grow in hot springs, geysers, and near volcanoes. Unlike other organisms, they can thrive in temperatures near 100°C, the boiling point of water. Methanogens named for their waste product, a gas called methane; lives in places such as swamps and inside the guts of cows and termites. They help these animals break down cellulose, a tough carbohydrate made by plants. This is an example of a mutualistic relationship.
nuclear envelope
Double membrane perforated with pores that control the flow of materials(protein and RNA) in and out of the nucleus.
indirect ELISA
ELISA that detects for antibodies 1.) A sample containing antigens is mixed with a specific antibody that's linked to an enzyme 2.) The enzyme-linked antibodies bond with the antigen 3.) A substrate binds to the enzyme • This test detects this when the substrate that corresponds to the linked enzyme is added; a color is produced when the binding occurs (a spectrometer detects this)
direct ELISA
ELISA that detects for antigens 1.) A sample containing antigens is mixed with a specific antibody that's linked to an enzyme 2.) The enzyme-linked antibodies bond with the antigen 3.) A substrate binds to the enzyme • This test detects this when the substrate that corresponds to the linked enzyme is added; a color is produced when the binding occurs (a spectrometer detects this)
Methods of Classifying and Identifying Microorganisms
EMINENT METHODS • In clinical microbiology, lab requisition forms are used to note types of specimens collected and tests to be conducted. • Transport media is used to collect and transport pathogens to a laboratory. • Morphological characteristics are useful for identifying eukaryotes; they can convey information regarding phylogenetic relationships. • Differential staining: Gram staining, acid-fast staining. This method is not useful for bacteria lacking cell walls. • Biochemical tests indicate the presence of bacterial enzymes.
Idophor
EPA-registered, intermediate-level hospital disinfectant
pyruvate oxidation
Each pyruvate molecules is oxidized and produces 1 acetyl-CoA, 1 CO2, and 1 NADH. The 2 carbons (acetate) combine with Coenzyme A to create [acetyl CoA]. NAD+ is reduced to NADH using H from the acetate. -2nd step of cellular respiration
Scanning Electron Microscope (SEM)
Electrons reflect from the surface of a specimen to create a three-dimensional image. (10x to *500,000x*) magnification
bacteriophage lambda (λ)
Enterobacteria phage λ (lambda phage, coliphage λ, officially Escherichia virus Lambda) is a bacteriophage, that infects the bacterial species Escherichia coli. RESULTS OF THE LYSOGENIC CYCLE •The host's cells become immune to reinfection by the same phage. •Phage conversion: the host cell exhibits new properties (some bacteria produce toxins only when it carries a lysogenic phage)
Topoisomerase
Enzyme that functions in DNA replication, helping to relieve strain in the double helix ahead of the replication for by breaking, swiveling and rejoining DNA ends
organic growth factors
Essential organic compounds an organism is unable to synthesize; obtained from the environment •Organic compounds obtained from the environment •Vitamins, amino acids, purines, and pyrimidines
Multicellular Animal Parasites
Eukaryotic Multicellular animals Parasitic flatworms and roundworms helminths •Parasitic flatworms and roundworms are called helminths •Not strictly microorganisms
ocular
Eyepiece of a microscope
Celcius to Fahrenheit
F=([9/5]C)+32
Kidneys
Filter blood from the renal arteries and produce urine as waste
Fimbriae
Fingerlike projection of the uterin (fallopian) tubes that drape over the ovary •Hairlike appendages that allow for attachment
urine (piss)
Fluid wastes removed from the body by the kidneys; this process cleans the urethra
nonionizing radiation
Forms of radiant energy that doesn't have enough energy to cause the ionization of atoms in living tissue. •Damages DNA by creating thymine dimers such as radio waves, microwaves, infrared light, and ordinary light (UV, 260 nm)
Ernst Haeckel (1834-1919)
German philosopher •Bacteria and fungi become subdivisions of kingdom Plantae Kingdom Protista was proposed for bacteria, protozoa, algae, and fungi
Thymus
Gland in the thoracic cavity (chest) above the heart where T lymphocytes mature.
Ovaries
Glands that produce the ova (egg cells) and hormones. The ova is then moved to the ovaduct
alcohol fermentation
Glycolysis is followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD+ and releasing carbon dioxide. produces ethanol + CO2 1.) Glucose is oxidized to pyruvic acid 2.) pyruvic acid is converted to acetaldehyde and CO2 3.) NADH reduces acetaldehyde to ethanol
Cilia
Hairlike projections that extend from the plasma membrane and are used for locomotion short projections; numerous consists of microtubules made of the protein tubulin
meiosis I
Homologous chromosomes separate The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell. *FEMALES*: Each month, a primary oocyte completes meiosis I, forming a *first polar body* & the *secondary oocyte* -the polar bodies ultimately disintegrate
MHC class I molecules
Human cells must express these molecules because they signal to NK cells (immune system) that they are a part of the human body. NK cells attack cells that don't possess MHC class I molecules. Class I MHC genes encode these molecules, which are glycoproteins expressed on the surface of nearly all nucleated cells; the major function of the class I gene product is presentation of peptide antigens to TC cells. • found on the membrane of nucleated animal cells
STEPS of transcription
INITIATION 1.) *RNA polymerase* attaches to the *promoter site*. The promoter site contains transcription factors. 2.) The RNA Polymerase and the transcription factors bind together, creating the initiation complex. 3.) The complex travels to the *termination site* of the DNA. 4.) As the complex moves towards the termination site, the section of the DNA helix which is encased by the RNA Polymerase unwinds and opens via *DNA Helicase*, revealing the two strands which comprise the DNA molecule. ELONGATION 5.) *pre-mRNA* (a special strand of DNA which acts as the precursor to mRNA) is synthesized by the RNA Polymerase as it travels along one of the revealed DNA strands. The pre-mRNA becomes longer as the RNA polymerase travels to the termination site. TERMINATION 6.) Once it reaches the termination site, the RNA polymerase, as well as the special DNA strand, dissociates from the DNA molecule. 7.) *Intron Splicing* occurs; A *spliciosome* find the dissociated special strand of DNA. The strand undergoes modifications. >A *5' cap* and a *3' Poly-A tail* is added to the strand. >The *introns are removed*. >The *exons are fused together*. These modifications transform the special DNA strand into a mature *mRNA* molecule. 8.) The mRNA leaves the nucleus by traveling through a nucleus pore, entering the cytoplasm. Eventually *translation* begins.
herd immunity
Immunity in most of a population (generally due to vaccines)
herd immunity
Immunity in most of a population; generally due to vaccines • Sporadic (irregular, random) Outbreaks are due to a lack of susceptible individuals
passive transport
In passive transport, substances cross the cell membrane without the cell expending energy, but in active transport substances are moved against a concentration difference at the cost of energy. •Passive processes: substances move from high concentration to low concentration; no energy is expended
allergies
Inappropriate or excessive immune responses to antigens or non-antigenic substances such as pollen, fur, a particular food, or dust; this is become of hypersensitivity.
Beta-glucans
Ingredients used in anti-aging cosmetics to help reduce the appearance of fine lines and wrinkles by stimulating the formation of collagen
ingestion
Intake of food •Opsonization: pathogen is coated with serum proteins (antibodies), making ingestion easier for the macrophage
phagosome
Intracellular vesicle containing material taken up by phagocytosis
phagolysosome
Intracellular vesicle formed by fusion of a phagosome with a lysosome, in which the phagocytosed material is broken down and digested by degradative lysosomal enzymes
ionization radiation
Ionizes water to release OH; damages DNA X rays gamma rays electron beams •Ionizes water to create reactive hydroxyl radicals •Damages DNA by causing lethal mutations
MacConkey Agar
Isolation and differentiation of lactose fermenting and non lactose fermenting enteric bacilli
dry heat sterilization
Kills by oxidation: •Flaming •Incineration •Hot-air sterilization (dry heat) an early method of sterilization in which hot air that is either vacant from water vapor or has very little of it (the moisture plays a minimal or no role in the process of sterilization) is used for conduction. Items should be dry before sterilization since water will interfere with the process. Dry heat destroys microorganisms by causing denaturation of proteins. The presence of moisture, such as in steam sterilization, significantly speeds up heat penetration. conduction: heat is absorbed by the exterior surface of an item and then passed inward to the next layer. Eventually, the entire item reaches the proper temperature needed to achieve sterilization. The proper time and temperature for dry heat sterilization is: 160 °C (320 °F) for 2 hours 170 °C (340 °F) for 1 hour High Velocity Hot Air sterilizers: 190°C (375°F) for 6 to 12 minutes
metaphase
Kinetochore microtubules form the chromosomes into a line across the center of the cell.
Protista
Kingdom composed of eukaryotes that are not classified as plants, animals, or fungi
fungi
Kingdom composed of heterotrophs (deriving its nutritional requirements from complex organic (containing carbon) substances); many obtain energy and nutrients from dead organic matter PATHOGENIC PROPERTIES •Toxic metabolic products •Provoke an allergic response •Trichothecene toxins inhibit protein synthesis •Proteases modify host cell membranes •Capsules prevent phagocytosis •Toxins can cause hallucinations, be carcinogenic and neurotoxic
enzymes
LIST •Coagulases: coagulate fibrinogen •Kinases: digest fibrin clots •Hyaluronidase: digests polysaccharides that hold cells together •Collagenase: breaks down collagen •IgA proteases: destroy IgA antibodies
ATP synthase
Large enzymatic protein that uses energy (from H+ ions) to bind ADP(adenosine diphosphate) and a phosphate group together to produce ATP(adenosine triphosphate) ATP synthase sometimes carries H+, diffusing it back down the concentration gradient. -ATP synthase is the main route to diffuse back down the membrane
diapedesis (emigration)
Leukocytes (phagocytes) squeeze through gaps in the endothelial cells and enter tissue fluid; occurs during inflammation
pigment
Light-absorbing molecule Colors seen are the colors least absorbed or reflected of the pigment.
plasma
Liquid part of blood
Meiosis vs. Mitosis
Meiosis/Mitosis haploid vs. diploid 4 vs. 2 8 phases vs. 4 phases genetically different vs. genetically identical crossing over vs. not xx tetrads vs. just x movement in homologous pairs vs. don't split into < in a2 vs. split into < in a1 less cells vs. more cells sexual vs. both sexual and asexual view at 1000x vs. view at 600x reproduction vs. replace lost or dead cells
immunilogical memory
Memory cells are vital in triggering the Secondary (memory r anamnestic) response, which occurs after a second exposure to an antigen. The memory cells from the initial encounter are activated, causing the immune system compared to the initial encounter to be stronger and quicker against the specific pathogen. This "memory" lasts many days. once an antigen has been recognized, the adaptive immune system adapts to the it with specific countermeasures designed to attack that antigen. • includes a "memory"; future responses against that specific antigen are more efficient after the initial encounter • Memory cells Antibody titer refers to the relative amount of antibody in a serum; it reflects intensity of the humoral (antibody-based) response • IgM is produced first, followed by IgG
semiconservative replication
Method of DNA replication in which parental strands separate, acting as templates, and produces molecules of DNA with one copied parental DNA strand and one new DNA strand
plate count
Method to measure the concentration of viable cells by counting the number of colonies that develop from a sample added to an agar plate •Count colonies on plates that have 30 to 300 colonies (CFUs) •To ensure the right number of colonies, the original inoculum must be diluted via serial dilution •Count the bacteria mixed into a dish with agar (the pour plate method) or spread on the surface of a plate (the spread plate method)
Capnophiles
Microbes that require high CO2 conditions
stain
Microbial cells lack contrast-so to see must be stained with a dye. Dyes are colored compounds related to organic solvent-benzene (6 Carbon ring) Most dyes are in form of sodium chloride salt They are basic or acidic compound that ionizes when dissolved in a compatible compound
Prostaglandins
Modified fatty acids that are produced by a wide range of cells and behave like hormones; they affect smooth muscles and increase mucus secretion
host attachment sites
Most viruses are only able to infect specific types of cells. This is because the spikes of the head of the virus are only able to unlock certain receptors of cell membranes. When the receptors are "unlocked", endocytosis occurs during which the cell takes in the capsid of the virus. The receptor of the host cell has been deceived. EXAMPLE Say a dog owner is sick because of a virus that infects the liver. Despite being near the human so much, the dog doesn't get sick. This is probably because the spikes of that strain of virus unlock the receptors of the human liver cell, but not the receptors of the dog liver cell. Because the spikes of viruses are specific to certain receptors, this is also why only the liver cells of the human, which have specific receptors, are infected in this example. (One type of cells have receptors that other types don't have.)
gene transfer
Movement of genetic information between organisms •Vertical gene transfer: transfer of genes from an organism to its offspring •Horizontal gene transfer: transfer of genes between cells of the same generation
facilitated diffusion
Movement of specific molecules across cell membranes through protein channels; a form of passive transport •solute combines with a transporter protein in the membrane •Transports ions and larger molecules across a membrane with the concentration gradient
amide
NH2 -1
seminiferous tubules
Narrow, coiled tubules that produce sperm in the testes.
centrosome
Networks of protein fibers; centrioles form the mitotic spindle; plays a critical role in cell division In animal cells, microtubules grow out from a centrosome near the nucleus. The centrosome has a pair of centrioles, each with nine triplets of microtubules arranged in a ring.
NADP
Nicotinamide adenine dinucleotide phosphate, an electron acceptor.
Introns
Non-coding segments of nucleic acid that lie between coding sequences. must be removed from pre-mRNA in order to create mRNA -They exit the nucleus when they're removed.
Prophase II (Stage 6)
Note that interphase is skipped this time around because there is no replication of DNA between Meiosis I and Meiosis II. At this point the chromosomes re-organize and the nuclear membranes start to dissolve again. Sister chromatids are again joined by a centromere. Spindles start to reform between centrosomes.
Telophase II (Stage 9)
Nuclear membranes start to form around the chromosomes again. A *cleavage* forms. Cytokinesis occurs and the two diploid cells have now divided into 4 haploid cells. In males this equates to 4 sperm cells. In females this creates 1 egg and 3 polar bodies which are useless in humans!
culture media
Nutrient solutions used to grow microbes in the laboratory TYPES •Culture medium: nutrients prepared for microbial growth •Sterile: no living microbes •Inoculum: introduction of microbes into a medium •Culture: microbes growing in or on a culture medium •Agar •Chemically defined media: the exact chemical composition is known •Complex media: extracts and digests of yeasts, meat, or plants; chemical composition of batches can vary > Nutrient broth > Nutrient agar •Reducing media: used for the cultivation of anaerobic bacteria
Hemolytic disease of the newborn (HDNB)
Occurs when an Rh- mother has an Rh+ fetus; this causes the mother to produce anti-Rh antibodies The Rh+ fetus will receive anti-Rh antibodies, damaging it's RBCs.
diffraction
Occurs when an object causes a wave to change direction and bend around it X-ray diffractions reveal DNA structure
Safety of Vaccines
On rare occasions, vaccines can cause the disease but there is no medical or scientific proof of MMR vaccines being linked to autism. Vaccines are generally the safest and most effective means of preventing infectious disease in children
first polar body
One of the products of meiosis I in oogenesis; contains half the chromosomes but little of the cytoplasm. affiliated with *secondary oocyte*
photosystem I
One of the two light-harvesting units of a chloroplast's thylakoid membrane; it uses the P700 reaction-center chlorophyll.
archaea
One of the two prokaryotic domains ancient unicellular prokaryotes that possess cell walls that do not contain peptidoglycan •Often live in extreme environments EMINENT EXAMPLES: •Methanogens (CO2+ 4H2 → CH4+2H2O) •Extreme halophiles •Extreme thermophiles
lymphocytes
One of the two types of white blood cells that are part of the body's immune system; found in the lymph; agranular Lymphocytes include natural killer cells, T cells, and B cells (for humoral, antibody-driven adaptive immunity). TYPES B lymphocytes form in the bone marrow and release antibodies that fight bacterial infections T lymphocytes form in the thymus and other lymphatic tissue and attack cancer cells, viruses, and foreign substances. Natural Killer Cells (NK cells) destroy target cells
Spleen
Organ near the stomach that produces, stores, and eliminates blood cells *stem cells
Psychrotrophs
Organisms that can grow in cold temperatures • 0 C to 30 C • Cause food spoilage
Chemoautotrophs
Organisms that use hydrogen sulfide or other chemicals as an energy source instead of light •Use energy from inorganic chemicals and CO2 as the carbon source •Energy is used in the Calvin-Benson cycle to fix CO2 They synthesize their own organic molecules from the fixation of carbon dioxide. These organisms are able to produce their own source of energy (food). The energy required for this process comes from the oxidation of inorganic molecules such as iron, sulfur or magnesium. Chemoautotrophs are able to thrive in very harsh environments, such as deep-sea vents, due to their lack of dependence on outside sources of carbon other than carbon dioxide.
Photoautotrophs
Organisms that use light as a source of energy to synthesize organic substances •Oxygenic: produces O2 •Anoxygenic: does not produce O2
epidermis
Outer layer of skin connected to the dermis via connective tissue contains no blood vessels, and cells in the deepest layers are nourished almost exclusively by diffused oxygen from the surrounding air and to a far lesser degree by blood capillaries extending to the outer layers of the dermis COMPRISED OF Merkel cells keratinocytes melanocytes Langerhans cells.
phosphoglycerate
PGA; a three-carbon molecule formed in the first step of the Calvin cycle
Protozoan and Helminths
PROTOZOAN: heterotrophic (unable to crate food, must consume organic matter), unicellular, animal-like protist HELMINTH: multicellular, parasitic worms PROTOZOANS / HELMINTHS Protozoans and helminths are often too large to be phagocytized. They are difficult to treat. 1.) Because of this the protozoan or helminth is coated with antibodies. 2.)Then, cells of the immune system cells attach to the Fc regions of these antibodies. 3.) This eventually causes the target cells of the protozoan or helminth to be lysed by chemicals secreted by the immune system cells.
Krebs Cycle (Citric Acid Cycle)
PYRUVIC OXIDATION Pyruvate is produced by glycolysis in the cytoplasm, but pyruvate oxidation takes place in the mitochondrial matrix (in eukaryotes) 1.) Pyruvic acid (from glycolysis) is oxidized and decarboxylation (loss of CO2) occurs. 2.) The resulting two-carbon compound attaches to coenzyme A, forming acetyl CoA and NADH CITRIC ACID CYCLE takes place in the matrix of the mitochondria 1.) Each of the two acetyl coenzyme A molecules enter the cycle. 2.) They combine with oxaloacetate to form citric acid •The oxidation of acetyl CoA produces NADH, FADH2, and ATP 3.) This results in the loss of two carbons in the form of carbon dioxide. 4.) The cycle can now begin again with the second Acetyl CoA. For each Acetyl CoA, the Krebs Cycle produces: 1 ATP 3 NADH 1 FADH2
light reactions
Part of photosynthesis that involves light solar(light) energy becomes chemical energy *ATP and NADPH are produced using hydrogen+ ions and electrons. -occur at the thylakoid membrane -chlorophyll absorbs energy from sunlight.
safranin
Pink colored counterstain used in gram stain
algae
Plantlike protists PATHOGENIC PROPERTIES •Some produce saxitoxin, a type of neurotoxin
Phenolics
Powerful tuberculocidal disinfectants an aromatic, organic compound with the molecular formula C6H5OH. It is a white crystalline solid that is volatile. The molecule consists of a phenyl group (−C6H5) bonded to a hydroxy group (−OH). Mildly acidic, it requires careful handling because it can cause chemical burns.
Fermentation
Process by which cells release energy in the absence of oxygen
Fermentation
Process by which cells release energy in the absence of oxygen •Does not use the Krebs cycle or ETC •Uses an organic molecule as the final electron acceptor •Produces only small amounts of ATP •Releases energy from the oxidation of organic molecules (NOTE to all the retards out there: •Oxidation does not require oxygen)
crossing over
Process in which homologous chromosomes exchange portions of their chromatids during meiosis. -greatly increases genetic variety
crossing over
Process in which homologous chromosomes exchange portions of their chromatids during meiosis; two chromosomes break and rejoin, resulting in the insertion of foreign DNA into the chromosome 1.) DNA from one cell aligns with DNA in the recipient cell. There is a nick in the donor DNA. 2.) DNA from the donor aligns with complementary base pairs in the recipient's chromosome. This can involve thousands of base pairs. 3.) RecA protein catalyzes the joining of the two strands. 4.) The result is that the recipient's chromosome contains new DNA. 5.) Complementary base pairs between the two strands will be resolved by DNA polymerase and ligase. The donor DNA will be destroyed. The recipient may now have one or more new genes.
cellular respiration
Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen •Oxidation of molecules liberates electrons to operate an electron transport chain •Final electron acceptor comes from outside the cell and is inorganic •ATP is generated by oxidative phosphorylation
Spores
Produced by meiosis. Becomes haploid organism sex cells single-celled reproductive bodies highly resistant to cold and heat damage; capable of new organisms
Kingdoms of Eukarya
Protista, Fungi, Plantae, Animalia
Eukaryotic Kingdoms
Protista: a catchall (broad) kingdom for a variety of organisms; autotrophic and heterotrophic - Grouped into clades based on rRNA Fungi: chemoheterotrophic; unicellular or multicellular; cell - walls of chitin; develop from spores or hyphal fragments Plantae • multicellular; cellulose cell walls; undergo photosynthesis Animalia • multicellular; no cell walls; chemoheterotrophic
Starch Hydrolysis Test
Purpose: •Differential test •Detects the production of amylase, an enzyme that hydrolysis starch Results: NEGATIVE: dark blue, starch is present POSITIVE: 1. Clearing of plate observed after iodine - Positive for amylase, positive for starch hydrolysis 2. No clearing observed after iodine - neg for amylase & starch hydr.
intron splicing
RNA splicing to remove introns and ligate exons
P680
Reaction center chlorophyll in the photosystem II
P700
Reaction center cholophyll in the photosystem I
Hives (urticaria)
Red, itchy, swollen spots/patches; seen in allergic reactions
Centromere
Region of a chromosome where the two sister chromatids attach
plasma membrane (cell membrane)
Regulates what enters and leaves the cell and separates the internal environment of the cell from the external environment ANATOMY •Phospholipid bilayer that encloses the cytoplasm •Peripheral proteins on the membrane surface •Integral and transmembrane proteins penetrate the membrane BEHAVIOR •Membrane is as viscous as olive oil •Proteins move freely for various functions (membrane fluidity) •Phospholipids rotate and move laterally •Self-sealing FUCTION •The plasma membrane's selective permeability allows the passage of some molecules, but not others •Contain enzymes for ATP production •Some membranes have photosynthetic pigments on foldings called chromatophores •Damage to the membrane by alcohols, quaternary ammonium (detergents), and polymyxin antibiotics causes leakage of cell contents
anaerobic respiration
Respiration that does not require oxygen Bacteria use a sulfate ion at the end of the respiratory chain. -Hydrogen sulfide(rotten egg odor) is the byproduct; not water.
aerobic respiration
Respiration that requires oxygen
rRNA
Ribosomal RNA; a noncoding type of RNA which can bind with certain proteins to form ribosomes. *Ribosomes must contain rRNA* to exist. 1.) transcribed from ribosomal DNA (rDNA) (In other words, ribosomes are synthesized in the nucleolus.) 2.) binds to ribosomal proteins to form the specific subunits of ribosomes. > physically and mechanically forces mRNA and tRNA through the ribosome, which processes and translates them into functioning proteins. > composes around 80% of cellular RNA despite never being translated into proteins itself. -Ribosomes are composed of approximately 60% rRNA and 40% other ribosomal proteins by mass.
RuBisCO
Ribulose carboxylase, the enzyme that catalyzes the first step of the Calvin cycle (the addition of CO2 to RuBP, or ribulose bisphosphate).
Bacillus
Rod shaped bacteria
helical capsid
Rod-shaped capsomeres that form a continuous helix around the nucleic acid
ribulose biphosphate
RuBP; a five-carbon carbohydrate that combines with CO2 to form two molecules of PGA in the first step of the Calvin Cylce
Tumor necrosis factor (TNF)
Secreted by macrophages and T cells; kills tumor cells and regulate immune responses and inflammation
Epinephrine (adrenaline)
Secreted by the adrenal medulla; increases heart rate and blood pressure and dilates airways; sympathomimetic (It's part of the "fight or flight" reaction.)
Motility
Self-movement; motile microbes possess appendages that allow movement TUBE METHOD TEST turbid or "tornado" HANGING DROP TEST
coccobacillus
Short round rod shaped bacteria
origins of replication (ORI)
Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.
Haptens (Incomplete Antigens)
Small molecules (such as peptides, nucleotides, and hormones) that aren't immunogenic by themselves. They become immunogenic when they're attached to body proteins. (Examples: Poison ivy, animal dander, detergents, and cosmetics.)
activation of the Compliment System
Some antigen-antibody complexes allow complement proteins to bind to it, causing the compliment system to destroying the antigen.
cofactor
Some enzymes require non-protein molecules called cofactors to be bound for activity. can be either inorganic or organic compounds metal ions can help in stabilizing nucleophilic species within the active site. can be either: coenzymes, which are released from the enzyme's active site during the reaction prosthetic groups, such as metal ions, which are tightly bound to an enzyme
Induction
Some genes don't allow gene expression unless its been stimulated with an inducer. The inducer "turns on" gene expression, meaning the genes are expressed and transcription occurs •Initiated by an inducer •Default position of an inducible gene is "off"
Metaphase II (Stage 7)
Spindles are fully formed again and attach to the centromeres. The chromosomes line up down the middle of the spindles. (Chromosomes line up like mitosis.)
Phenol
Strong, high pH disinfectant any of a family of organic compounds characterized by a hydroxyl (―OH) group attached to a carbon atom that is part of an aromatic ring. Besides serving as the generic name for the entire family, the term phenol is also the specific name for its simplest member, monohydroxybenzene (C6H5OH), also known as benzenol, or carbolic acid.
Oxidation
Substances being oxidized lose electrons. The charge of the reactant becomes more positive. The oxidizing agent gains electrons.
reduction
Substances being reduced gain electrons. The charge of the reactant becomes more negative(reduced).
Invasins
Surface proteins produced by bacteria that rearrange actin filaments of the cytoskeleton in such a way that the bacteria is able to invade the host •Causes membrane ruffling •They can use actin to move from one cell to the next.
Carl Linnaeus (1735)
Swedish botanist, zoologist, and physician who formalized binomial nomenclature, the modern system of naming organisms. the "father of modern taxonomy" introduces kingdoms Plantae and Animalia
Clusters of differentiation (CD)
T cells are further classified by the presence of certain glycoproteins (proteins with attached carbohydrates) or other specific molecules on their surface • cluster/classification determinant molecules (CD molecules): signature, specific molecules found on cells that indicate their classification T-CELL CLASSIFICATION • CD4+: a marker (CD molecule) on T cells indicating that the T cell is a T helper cell (TH). This marker interacts with B cells via cytokine signaling and interacts directly with the antigen(s) and also facilitate the binding of MHC class II molecules on B cells and APCs. • CD8+: a marker (CD molecule) found on T-cells that indicates that the T cell is a cytotoxic T lymphocyte (CTL); this marker functions to bind to MHC class I molecules
T helper cells
T lymphocytes with CD4 receptors on their cell-surface membranes, which bind to antigens on antigen-presenting cells and produce interleukins, a type of cytokine.
Domains of Life
THREE DOMAINS Eukarya •Animals, plants, fungi, and protists •Eukaryotes originated from infoldings of prokaryotic plasma membranes •Endosymbiotic bacteria developed into organelles Bacteria Archaea •Methanogens •Extreme halophiles •Hyperthermophiles •Developed by Woese in 1978; based on sequences of nucleotides in rRNA
Metaphase I (Meiosis)
Tetrads are lined up at the metaphase plate; Spindle fibers attach -many pairings can potentially occur, greatly increasing genetic variation
Holoenzyme
The "whole" enzyme (apoenzyme + cofactor)
latent viral infection
The ability of a pathogenic virus to lie dormant within a cell during the lysogenic part of the viral life cycle Latent viruses remain in asymptomatic host cells for long periods and can reactivate due to changes in immunity •Cold sores, shingles
quorum sensing
The ability of bacteria to sense the presence of other bacteria via secreted chemical signals.
transformation principle
The ability of some live bacteria to take traits from other bacteria-*including dead ones*-by directly taking components of their DNA. Griffith, then later Avery, McCarty, and MacLeod found strong evidence that DNA is the "transforming principle" that encodes genetic information.
cleavage furrow
The area of the cell membrane that pinches in and eventually separates the dividing cell Actin filaments form a contractile ring along inside of plasma membrane. occurs during cytokinesis in animals cells, and protists without cell walls)
base
The bottom of the microscope, used for support
peptide bond
The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid
morbidity
The condition of being diseased; the rate of disease infection in a population morbid: (adj.) in an unhealthy mental state, extremely gloomy; caused by or related to disease, unwholesome
oxidizing agent
The electron acceptor in a redox reaction; they shut down cellular enzyme systems
heat
The energy transferred between objects that are at different temperatures •High temperatures are responsible for denaturing enzymes. Thermal death point (TDP): lowest temperature at which all cells in a liquid culture are killed in 10 minutes Thermal death time (TDT): minimal time for all bacteria in a liquid culture to be killed at a particular temperature Decimal reduction time (DRT): time in minutes required to kill 90% of a population at a given temperature
substrate-level phosphorylation
The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.
Glycocalyx
The external surface of a plasma membrane that is important for cell-to-cell communication •carbohydrates bonded to proteins and lipids in the plasma membrane •found in animal cells
Glycocalyx
The external surface of a plasma membrane vital for cell-to-cell communication * composed of the caspule and the slime layer
FEMALE Anatomy of a flower
The female organ of the flower is the *pistil*. The pistil is usually located in the center of the flower and is made up of three parts: the *stigma*, the *style*, and the *ovary*. The ovary yields fruit when fertilized.
Anaerobic electron acceptors
The final electron acceptor in the electron transport chain is not O2. •Yields less energy than aerobic respiration NO3- products: NO2-, N2 + H2O SO4- products: H2S + H2O CO3 2- produts: CH4 + H2O
ribulose 5-phosphate
The five-carbon sugar ribulose, phosphorylated at carbon 5; a precursor for the synthesis of nucleotides produced from the Pentose Phosphate Pathway
double helix
The form of native DNA, referring to its two adjacent polynucleotide strands of a spiral shape.
Chargaff's 2nd Rule
The frequencies of the nitrogenous bases adenine, guanine, cytosine, and thymine in DNA vary between species. guanine pairs with cytosine adenine pairs with thymine (Composition of DNA varies between different organisms.)
prophage
The genome from a bacteriophage that has been inserted into a specific site on the host's bacterial chromosome
severity
The harshness or intensity of a disease •Latent disease: the causative agent is inactive for a time; once it activates it produces symptoms •Herd immunity: immunity in most of a population (Compare with lethality)
dysregulation
The impairment of a physiological mechanism used in regulation
congenital immunodeficiency
The inability to produce specific antibodies or T cells due to an individual's genotype
lysogenic conversation
The incorporation of a phage's genes into a host's chromosome • results in changes of the characteristics of a microbe due to incorporation of the prophage
MALE Anatomy of a flower
The male reproductive organ(s) is the *stamen*, which comprises the *anther* and the *filament*. The anther produces *pollen*, which comprises male gametes, and is supported by the *filament*. Each anther contains 4 *microsporangia*, or pollen sacs. Each microsporangium contains hundreds of *microsporocytes* (microspore mother-cells) that will each give rise to four spores (immature pollen grains). Upon maturation of the pollen (bottom), the pollen sac walls split open and the mature pollen grains (male gametophytes) are released.
phosphorylation
The metabolic process of introducing a phosphate group into an organic molecule •ATP is generated by the phosphorylation of ADP; requires energy TYPES Substrate-Level Phosphorylation •ATP generated when high-energy PO4- (phosphate group) is transferred from a phosphorylated compound to ADP Oxidative Phosphorylation •Electrons are transferred from one electron carrier to another along an electron transport chain on a membrane that releases energy to generate ATP
Western blot
The most common confirmation test for the HIV virus in the United States; detects the presence of specific proteins in a sample. DNA, RNA, or protein molecules contained in the sample are separated depending on size and electrical charge (gel electrophoresis) 1. Proteins in a mixture are separated by size using gel electrophoresis 2. Separated proteins are transferred from the gel to a "membrane," maintaining their pattern of separation (this is the "blotting" part) 3. Proteins of interest in the mixture are bound to a "primary" antibody that recognizes them. 4. The primary antibody is visualized using a "secondary" antibody coupled to an enzyme 5. The enzyme is exposed to its substrate and catalyzes a reaction that produces detectable light.
C3 photosynthesis
The most common form of photosynthesis in which atmospheric CO2 is used to form 3-phosphoglycerate, a three-carbon sugar. CO2 enters through stomata on leaves --> water exits the leaf
leading strand
The new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' to 3' direction. polymerase III synthesizes complementary strand by continuously elongating the new DNA in the 5'-3' direction -Only requires 1 primer
antiparallel
The opposite arrangement of the sugar-phosphate backbones in a DNA double helix. New DNA strands can only elongate in the 5' --> 3' direction NOTE: The 2 new strands formed during DNA replication must also be *anti-parallel* to their template strand. Consider that since the original strand and new strand must bind together, the nitrogen bases of each strand must match. The pattern of the new strand adopts a corresponding "opposite" pattern in relation to the original strand.
active site
The part of an enzyme or antibody where the chemical reaction occurs. The substrate binds to the active site.
Nutrition
The process by which your body takes in and uses food for health and growth; heavily influenced by your diet a predisposing factor that can make the body more susceptible to disease
gene silencing
The process in which a gene or gene sequence that is not expressed; accomplished through microRNA Since every type of cell in an organism contains the same genome, but each individual cell decides which aspects of the genome are relevant for its purposes, some parts of the genome must be suppressed. Unlike genes that are mutant due to DNA sequence alterations, genes deactivated by silencing can be reactivated.
clonal selection
The process in which an antigen selectively binds to and activates only the lymphocytes that have receptors specific for the antigen. These selected lymphocytes then proliferate and differentiate into a clone of effector cells and a clone of memory cells specific for the stimulating antigen
Photophosphorylation
The process of generating ATP from ADP and phosphate by means of a proton-motive force generated by the thylakoid membrane of the chloroplast during the light reactions of photosynthesis
Sterilization
The process that completely destroys all microbial life, including spores and beneficial microbes.
Photophosphorylation
The production of ATP by chemiosmosis during the light reactions of photosynthesis •Occurs only in light-trapping photosynthetic cells •Light energy is converted to ATP when the transfer of electrons (oxidation) from chlorophyll pass through a system of carrier molecules •Series of enzymatically catalyzed chemical reactions •Extracts energy from organic compounds and stores it in chemical form (ATP)
oxidative phosphorylation (electron transport chain)
The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration. •Series of enzymatically catalyzed chemical reactions •Extracts energy from organic compounds and stores it in chemical form (ATP)
proton motive force (PMF)
The proteins of the electron transport chain (I, III, and IV) pump H+ into the intermembrane space. This system releases energy used to pump hydrogen across the inner membrane, setting up a proton gradient responsible for the production of ATP.
zone of inhibition
The region around a chemical saturated disc, where bacteria are unable to grow due to adverse effects of the compound in the disc. •Evaluates the efficacy (effectiveness) of chemical agents •Filter paper disks are soaked in a chemical and placed on a culture •Look for the zone of inhibition(s) around disks
Dehydrogenation
The removal of hydrogen from a molecule
Cytolysis
The rupturing of a cell due to excess internal pressure; excess water enters the cell This process can occur intentionally when things like penicillin are used to kill pathogens. •Activated complement proteins create a membrane attack complex (MAC)
genetics
The scientific study of heredity •Alteration of bacterial genes and gene expression •Cause of disease •Prevent disease treatment •Manipulated for human benefit
G2 phase
The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.
specific epithet
The second part of a binomial referring to one species of a genus.
DNA sequence
The sequence in which the nitrogenous bases [adenine (A), cytosine (C), guanine (G), and thymine (T)] are arranged in a gene or a strand of DNA of an organism's genome. -order of nucleotides in a strand of DNA
antigen-binding site
The site on an immunoglobulin (antibody) or T-cell receptor molecule that binds to a specific antigen
Anaphase II (Stage 8)
The spindles pull the sister chromatids apart and travel to a different pole.
gametophyte
The stage in the life cycle of a plant in which the plant produces gametes, or sex cells.
extracellular matrix
The substance in which animal tissue cells are embedded, consisting of protein and polysaccharides. -composed of glycoproteins such as collagen and fibronectin -ECM proteins bind to receptor proteins in the plasma membrane called integrins
human pathogens
The survey of human pathogens produced a count of 1,407 human pathogen species, with 177 (13%) species regarded as emerging or reemerging (Appendix). These pathogenic species are comprised of: 208 viruses 538 bacteria 317 fungi 287 worms 57 parasitic protozoa
S phase
The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.
nucleic acid
The term nucleic acid is the overall name for DNA and RNA. >classified as biopolymers, or small biomolecules >essential to all known forms of life They are composed of *nucleotides*, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. If the sugar is a compound ribose, the polymer is RNA (ribonucleic acid); if the sugar is derived from ribose as deoxyribose, the polymer is DNA (deoxyribonucleic acid).
C4 photosynthesis
The two-step photosynthetic pathway in which CO2 is first fixed in mesophyll cells to form 4-carbon acids, then the 4-carbon acids are converted to malate. The malate is shuttled to bundle sheath cells and releases CO2. RuBisCO picks it up as if normal. Example: corn; sugar cane
Diagnostic Immunology
The use of immunological methods to identify pathogenic microbes; specific antibodies will react only with a corresponding specific antigens. • Either antigen or antibody can be used • Reactions are visible with a naked eye Sensitivity: probability that the test is reactive if the specimen is a true positive Specificity: probability that a positive test will not be reactive if a specimen is a true negative
T-even bacteriophage
This becteriophage infects Escherichia coli. LYTIC CYCLE •Attachment: phage attaches by the tail fibers to the host cell •Penetration: the phage's lysozyme opens the cell wall; tail sheath contracts, making the tail core inject viral DNA into the cell •Biosynthesis: production (synthesis) of phage DNA and proteins •Maturation: assembly of phage particles •Release: the phage's lysozyme breaks the cell wall and the new phages are free; this cycle repeats ANATOMY OF T-EVEN BACTERIOPHAGE icosahedral capsid head central tube collar base plate tail pins fibers
steps of translation
This process translates the information of the mRNA into a protein. INITIATION 1.) A small ribosomal subunit attaches to an mRNA molecule created via transcription at the mRNA's 5' cap. The SRSU travels along the strand until a section of the mRNA molecule binds with the SRSU. The binding occurs when the small ribosomal subunit finds the *start codon* of the mRNA molecule. 2.) An initial uncharged *tRNA* carries an amino acid to the small ribosomal subunit. The type of amino acid directly corresponds (anti-parallel) to the *anticodon* sequence of the tRNA. 3.) Complimentary base pairing occurs between the anticodon of the tRNA and the *codon* of the mRNA. > Since the amino acid is binded with the tRNA and the tRNA is binded with the mRNA, by extension the amino acid is binded to the mRNA. 4.) A *large ribosomal subunit* binds with the small ribosomal subunit after the initial tRNA has binded to the start codon. > This encapsulates the initial tRNA and its amino acid in the large and small ribosomal subunits. >This newly formed hybrid complex of the large and small subunits is called the *initiation complex* of translation. There are three distinct regions of space in this complex: the *E, P, and A sites.* > Each of these sites can contain a tRNA molecule binded with an amino acid. The P site of the first initiation complex holds the initial tRNA molecule and its amino acid. ELONGATION 5.) Another tRNA carries an amino acid to the initiation complex. It occupies the A site. This molecule is charged. > The A site is to the right of the central P site. The A site is closest to the 3' direction. The E site left of the cenrtal P site and is closest to the 5' direction. 6.) The A site tRNA binds with the mRNA molecule by the binding of the codon (of the mRNA) and the anticodon (of the tRNA). 7.) The amino acids of the P site and A site tRNAs bind together via a *peptide bond*. These linked amino acids are connected to whatever tRNA occupies the P site. 8.) The initiation complex moves one codon length to the 3' end. The tRNAs don't move. The movement to the complex occurs in such a way that the P site uncharged tRNA now occupies the E site and the A site charged tRNA now occupies the P site. 9.) a.) The E site tRNA exits the initiation complex. The peptide bonded amino acids stay with whichever tRNA occupies the P site. (At this point, there are two peptide bonded amino acids with the tRNA at the P site.) b.) The A site accepts another tRNA carrying an amino acid. 10.) The tRNAs shift positions when the inititiation complex moves again. (There are now 3 peptide bonded amino acids with the tRNA at the P site.) 11.) This cycle continues until the initiation complex travels so far along the 3' end that it reaches the *stop codon*. As this cycle continues, the amino acid chain becomes longer as more amino acids are joined together. This amino acid chain is a *polypeptide*. TERMINATION 12.) The initiation complex reaches the stop codon. A *release factor* binds to the A site. This causes the polypeptide, which in this case is very close to being a *protein*, to be released from the tRNA in the P site. 13.) The entire complex dissociates. It can be reassembled, starting the process again at the *initiation stage*.
The Third Golden Age of Microbiology
This time-frame includes the present (2020). MODERN ISSUES Infectious diseases kill about 15 million people globally each year. - More than 100,000 people die from bacterial infections each year in the United States. polymicrobial diseases: A pathogen can cause more than one disease, and a disease can be caused by more than one microbe Pathogens are becoming resistant to antimicrobials. - New diseases are emerging, and old diseases are reemerging. - Superbugs (antibiotic resistant) bioterrorism: pathogens can be used intentionally to infect large numbers of people (anthrax, smallpox, plaque) •Disease transmission has worsened due in part to mass traveling via airplanes. •Emerging infectious diseases such as ebola, AIDS, SARS, bird flu, and the coronavirus •Zoonotic: diseases that spread from animals to humans (Diseases can "make the switch" from only animals to humans too.)
intermediate filaments
Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments. -Support cell shape and fix organelles in place
COMPONENTS OF THE CYTOSKELETON
Three main types of fibers make up the cytoskeleton: -Microtubules: thickest of the three components of the cytoskeleton -Microfilaments: also called actin filaments, are the thinnest components -Intermediate filaments: fibers with diameters in a middle range
Vascularization
Tumor cells need nutrients. The genes that control angiogenesis (the growth of new blood vessels) are often overexpressed in tumor cells because the genes that inhibit it are inactivated. • When a tumor becomes vascularized (connected to the body's blood supply), the immune system fails to recognize it (invisible to the immune system).
on/off switch
Turns the light source on and off
Adaptive Immunity types
Types of Adaptive Immunity • Naturally acquired active immunity Resulting from infection • Naturally acquired passive immunity Transplacental (mother passes antibodies to fetus) or via colostrum (milk) • Artificially acquired active immunity Injection of vaccination (immunization) • Artificially acquired passive immunity Injection of antibodies
stop codon
UAG, UAA, or UGA; Codon that signals to ribosomes to stop translation
Ig G (Immunoglobulin G)
Used to fight against bacteria, viruses, and toxins • smallest Ig • in blood
Live attenuated vaccines
Weakened pathogen that closely mimics an actual infection; confers lifelong cellular and humoral immunity
chiasmata
X-shaped regions of chromosomes where crossing over occurred.
Turners
XO ("O" indicates missing or structurally altered chromosome.)
Kleinfelter's Syndrome
XXY
Jacob's syndrome
XYY
Koch's Postulates
a (mostly) reliable sequence of experimental steps for directly identifying a specific microbe to a specific disease proposed by Robert Koch (1876) 1.) The suspected pathogen must be present in *all* cases of the disease and absent from healthy animals. 2.) The suspected pathogen must be grown in *pure culture*. 3.) Cells from the *pure culture* of the suspected pathogen must cause disease in a healthy animal. 4.) The suspected pathogen must be *re*isolated to be verified as the same pathogen from the pure culture.
Koch's Postulates
a (mostly) reliable sequence of experimental steps for directly identifying a specific microbe to a specific disease; proposed by Robert Koch in 1876. STEPS 1.) The suspected pathogen must be present in all cases of the disease and absent from healthy animals. 2.) The suspected pathogen must be grown in pure culture. 3.) Cells from the pure culture of the suspected pathogen must cause disease in a healthy animal. 4.) The suspected pathogen must be reisolated to be verified as the same pathogen from the pure culture.
pentose
a 5-carbon sugar produced from Pentose Phosphate Pathway and is an important intermediate used in the synthesis of nucleic acids, glucose from CO2 in the photoshythesis and certain amino acids
Transposons
a DNA sequence that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Transposition often results in duplication of the same genetic material. can "copy-paste" or "cut and paste" DNA "jumping genes" •Contain insertion sequences (IS) that code for transposase, which cuts and reseals DNA •Complex transposons carry other genes (i.e. antibiotic resistance)
CD4+
a T cell marker than indicates that the T cell • is a Helper T cell • interacts with MHC Class II molecules • secretes large amounts of cytokines for sending messages This marker interacts with B cells via cytokine signaling and interacts directly with the antigen(s) and facilitate the binding of MHC class II molecules on B cells and APCs.
CD8+
a T cell marker than indicates that the T cell is a cytoxic T lymphocyte (CTL) and functions to bind to MHC class I molecules. • The cells of the human body possess endogenous antigens that connect to MHC class I molecules. This marker activates T cells into cytotoxic T lymphocytes (CTL) with the help of TH cells and costimulatory signals. • CTLs recognize and kill the body's own cells if they are infected or cancerous.
Scientific Nomenclature (binomial nomenclature)
a binomial system of naming and classifying organisms (genus + specific epithet) must be underlined or italicized established by Carolus Linnaeus in 1735 EXAMPLES •Escherichia coli GENUS: Escherichia named after Theodor Escherich, who discovered it SPECIFIC EPITHET: coli describes the bacterium's habitat: the large intestine, or colon •Staphylococcus aureus GENUS: Staphylococcus describes the clustered (staphylo-) spherical (coccus) cells SPECIFIC EPITHET: aureus describes the gold-colored (aureus) colonies
oligodynamic actions of heavy metals
a biocidal effect of metals, especially heavy metals, that occurs even in low concentrations; antimicrobial effects in exceedingly small amounts •Denature proteins Ag, Hg, Cu, Zn •Silver nitrate is used to prevent ophthalmia neonatorum •Mercuric chloride prevents mildew in paint •Copper sulfate is an algicide •Zinc chloride is found in mouthwash Scholarly texts from ancient India promoted the use of brass and silver in ritual cleansing practice as well as in consumption of food and drink. The ancient Indian medical text Sushruta Samhita promoted the use of specific metals in surgical procedures as a measure to prevent infection. Brass doorknobs and silverware both exhibit this effect to an extent.
Nigrosin
a black anionic (negatively) charged dye. The negatively charged dye is repelled by the negatively charged surface of the bacterial cell.
enzyme-linked immunosorbent assay (ELISA)
a blood test that measures the presence and amount of antibodies in the blood; commonly used to determine if someone has antibodies related to certain infections • Most commonly used for antigens affiliated with acquired immunodeficiency syndrome (AIDS) virus • positive result means the person has been exposed to virus TYPES Direct ELISA: detects antigens 1.) A sample containing antigens is mixed with a specific antibody that's linked to an enzyme 2.) The enzyme-linked antibodies bond with the antigen 3.) A substrate binds to the enzyme • This test detects this when the substrate that corresponds to the linked enzyme is added; a color is produced when the binding occurs (a spectrometer detects this) Indirect ELISA: Detects antibodies
systemic autoimmunity
a broad range of related diseases characterized by dysregulation of immune system which give rise to activation of immune cells to attack autoantigens and resulted in inappropriate inflammation and multitissue damages.
Plasmolysis
a cell shrinks inside its cell wall while the cell wall remains intact. (hypertonic solutions)
Chemokines
a chemical secreted by blood vessel endothelium and monocytes during an adaptive immune response to attract phagocytes to an area
Nondisjuntion karyotype
a chromosome fails to seperate from it's homologue during meiosis
Myasthenia gravis
a chronic autoimmune disease that affects the neuromuscular junction and produces serious weakness of voluntary muscles; occur when antibodies coat acetylcholine receptors, causing muscles to fail to receive nerve signals
Toll-like receptors (TLRs)
a class of proteins that play a key role in the innate immune system; they are single-pass membrane-spanning receptors usually expressed on sentinel cells that recognize structurally conserved molecules derived from microbes •Toll-like receptors (TLRs) on host cells attach to pathogen-associated molecular patterns (PAMPs) •TLRs bound to PAMPs induce the release of cytokines from the host cell (this regulate the intensity and duration of immune responses). Once these microbes have breached physical barriers such as the skin or intestinal tract mucosa, they are recognized by TLRs, which activate immune cell responses. * helps the immune system to recognize molecules that are broadly shared by pathogens * expressed on the membranes of leukocytes including dendritic cells, macrophages, natural killer cells, cells of the adaptive immunity such as T cells and B cells, and non-immune cells
Acute-phase proteins (APP)
a class of proteins whose plasma concentrations increase or decrease in response to inflammation This response is called the acute-phase reaction. The acute-phase reaction characteristically involves fever, acceleration of peripheral leukocytes, circulating neutrophils and their precursors. TYPES • Histamine: causes contraction of smooth muscle and dilation of capillaries. • Kinins: polypeptides that cause vasodilation and smooth muscle contraction. • Prostaglandins: causes vasodilation, inhibits platelet aggregation, bronchodilation • Leukotrienes: originally isolated from leukocytes; they are metabolites of arachidonic acid, containing three conjugated double bonds • Cytokines
Cluster determinant molecules (CD)
a cluster of antigens or molecules in which antibodies react to that characterizes a cell surface marker; these specific molecules indicate the classification of a type of cell
Flavin adenine dinucleotide (FAD/FADH2)
a cofactor that acts as a soluble (not membrane-bound) electron carrier (can be reversibly oxidized and reduced) (FAD) (FADH2)
lymph
a colorless fluid containing white blood cells, which bathes the tissues and drains through the lymphatic system into the bloodstream •carries microbes to lymph nodes where lymphocytes and macrophages destroy the pathogen
Recombination
a combining of genes or characters different from what they were in the parents; contributes to cell diversity
capsid
a component of the head of a virus that contains the nucleic acid, singe or double-stranded DNA and/or single or double-stranded RNA can appear as helical or Icosahedral helical: helix-shaped icosahedral: 20 equilateral triangular faces arranged around the surface of a hollow sphere containing the nucleic acid.
octamer
a composition of two copies each of four different types of histones
superoxide
a compound that contains the superoxide ion, chemical formula O2^-. A reactive oxygen ion that is particularly important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature. (O2^-) + (O2^-) + (2H^+) = H2O2 + O2
opprotunistic pathogens
a condition in which some normal microbiota can become infectious (example: trimester of pregnancy)
hyperactivity
a condition of excessive activity
Drug-induced cytotoxic reactions
a cytotoxic reaction that occurs due to the introduction of a drug EXAMPLE: Thrombocytopenic purpura
india ink stain
a dark differential stain used to visualize Cryptococcus neoformans
cyclic AMP (cAMP)
a derivative of adenosine triphosphate (ATP) and is used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway; A compound formed from ATP that acts as a second messenger •it builds up in a cell when glucose isn't available •cAMP binds to the lac promoter, initiating transcription and allowing the cell to use lactose
spectrum of microbial activity
a diagram that conveys a range of different types of microorganisms and shows which antimicrobial drug they are affected by • Narrow spectrum of microbial activity: drugs that affect a narrow range of microbial types • Broad-spectrum antibiotics: affect a broad range of gram-positive or gram-negative bacteria
acid fast stain
a differential stain used to identify bacteria that are not decolorized by acid-alcohol; used to differentiate acid fast organisms Acid fast bacteria have a high content of mycolic acids in their cell walls. They will appear red, while nonacid fast bacteria will stain blue/green with the counterstain with the Kinyoun stain. aci Step 1. Apply carbol fuchsin to a fixed slide for 1 minute followed by rinsing. Step 2. The decolorizing agent, 3% hydrogen chloride (HCl), is applied for 2 minutes and remove the primary stain and rinse. Step 3. Apply the counterstain, methylene blue, for 2 minutes then rinse. Step 4. Allow to dry and observe slide with a light microscope.
autoimmune disease
a disease in which the immune system attacks the organism's own cells
autoimmune disease
a disease in which the immune system attacks the organism's own cells when it responds to self antigens, causing damage to the organs EXAMPLES • Graves' disease: Abnormal antibodies in the thyroid produce excessive amounts of hormones • Myasthenia gravis: Antibodies coat acetylcholine receptors; muscles fail to receive nerve signals
aquired immunodeficiency syndrome (AIDS)
a disease in which the immune system is weakened due to the inability to produce specific antibodies or T cells, due to drugs or disease; obtained during the life of an individual rather than inherited HISTORY 1981: United States; a cluster of cases of Pneumocystis pneumonia, Kaposi's sarcoma, and loss of immune function are discovered in young homosexual men 1983: the discovery of a virus causing the loss of immune function (HIV) selectively infects T helper cells
smallpox
a disease that causes a high fever and often death • The overall deadliest known disease in the history of the world. • In the 20th century approximately 500,000,000 people died of this disease.
chronic disease
a disease that develops gradually and continues over a long period of time, including permanently (Walt's cancer and dumb hoe of a wife.)
noncommunicable disease
a disease that is not transmitted from one host to another
communicable disease
a disease that is transmitted from one host to another
Human Karyotype
a display of the full set of 46 human chromosomes
dispersive replication
a disproved model of DNA synthesis suggesting more or less random interspersion of parental and new segments in daughter DNA molecules
hanging drop slide
a drop of bacteria hangs from a coverslip, and is dangling in the air TEST RESULTS Brownian Movement: molecules bump into each other, movement but unintended by the microbe indicates negative True Movement: vectorial movement by the microbe indicates positive
analog
a drug or molecule that has a very similar structure to another drug; sometimes the body uses these instead of the correct molecule; this can occur as a mutation
selective toxicity
a drug that kills harmful microbes without damaging the host
Fragmentation of filaments (splitting)
a form of asexual reproduction of multi-cellular organisms in which an organism is split into fragments. Each of these fragments develop into matured, fully grown individuals that are identical to their parents. The splitting may or may not be intentional - it may or may not occur due to man-made or natural damage by the environment or predators. This kind of organism may develop specific organs or zones that may be shed or easily broken off. If the splitting occurs without the prior preparation of the organism, both fragments must be able to regenerate the complete organism for it to function as reproduction. EXAMPLES seen in many organisms, such as: filamentous cyanobacteria molds lichens many plants animals such as sponges, acoel flatworms, some annelid worms and sea stars.
Virion
a fully-formed virus that is able to establish an infection in a host cell COMPONENTS OF A VIRION •Nucleic acid Both DNA or RNA can be single or double-stranded; as well as linear or circular shaped •Capsid a protein coat made of capsomeres (subunits) •Envelope consists of lipids, proteins, and carbohydrates; a coating of some viruses •Spikes projections of the outer surface of the head; can attach to hosts (lock-and-key)
operons
a functioning unit of DNA, comprised of multiple genes under the control of a single promoter, that coordinate the regulation of gene expression > mostly in prokaryotes, but rarely also eukaryotes ANATOMY OF AN OPERON •Promoter: segment of DNA that the RNA polymerase initially binds to in order to initiate the transcription of structural genes •Operator: segment of DNA that controls the transcription of structural genes Operons are comprised of the operator and promoter sites, and the structural genes that they control. OVERVIEW OF AN OPERON The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splicing to create monocistronic mRNAs that are translated separately. (i.e. several strands of mRNA that each encode a single gene product.) The result of this is that the genes contained in the operon are either expressed together or not at all. Several genes must be co-transcribed to define an operon.
Agar
a gel-like polysaccharide compound used for culturing microbes; extracted from certain red algae •Complex polysaccharide •Used as a solidifying agent for culture media in Petri plates, slants, and deeps •Generally not metabolized by microbes TEMPERATURE •Liquefies at 100 C •Solidifies at around 40 C
selectable marker
a gene introduced into a cell, especially a bacterium or to cells in culture, that confers a trait suitable for artificial selection. •Positive (direct) selection: beneficial traits; detects mutant cells because they grow or appear different than unmutated cells •Negative (indirect) selection: detrimental traits; detects mutant cells that cannot grow or perform a certain function
lac operon
a gene system whose operator gene and three structural genes control lactose metabolism This operon, like all operons, consists of a promoter (the site is where polymerase initially binds to initiate transcription, creating products), an operator (which is to the right of the promoter on the DNA strand, and determines whether the polymerase is allowed to initiate transcription), and structural genes (which are to the right of the operator). The structural genes code for enzymes that utilize lactose. When the polymerase synthesizes mRNA, and uses the codes of these genes, eventually leading to the creation of the enzymes. Bacteria use these enzymes to metabolize (eat) the lactose sugars. NO LACTOSE PRESENT Whenever there isn't any lactose present it means the organism hasn't consumed anything that breaks down into lactose. There is a repressor that has been bound to the promoter. It prevents the enzymes from being made. This is because the enzymes would be redundant without any lactose to break down. The energy spent creating these enzymes would be wasted. LACTOSE PRESENT When there is enough lactose is present, some of the lactose will bind to the repressor (at an allosteric site). The repressor will change shape because of this, and won't be able to bind to the operator anymore. This allows the enzymes to be created since the polymerase is able to transcribe without being obstructed by the repressed operon. The resulting enzymes break down the rest of the lactose.
regulatory gene
a gene that produces a repressor substance that inhibits an operator gene
direct damage
a general mechanism utilized by pathogenic organisms to ensure infection and destruction of the host cell SCENARIOS • pathogen disrupts host cell function • pathogen uses host cell nutrients • pathogen produces waste products • pathogen multiplies in host cells and causes ruptures
Nocardia
a genus of weakly staining Gram-positive, catalase-positive, rod-shaped bacteria. It forms partially acid-fast beaded branching filaments (acting as fungi, but being truly bacteria). It contains a total of 85 species. Some species are nonpathogenic, while others are responsible for nocardiosis.
Glycocalyx (pericellular matrix)
a glycoprotein and glycolipid covering that surround the cell membranes of some bacteria, epithelia, and other cells; external of the cell wall •Viscous and gelatinous •Made of polysaccharide and/or polypeptide Two types Capsule •neatly organized and firmly attached Slime layer •unorganized and loose •A source of nutrition when energy stores are low and protecting them from dehydration •Contributes to virulence •Capsules prevent phagocytosis •Extracellular polymeric substance helps form biofilms Most animal epithelial cells have a fuzz-like coating on the external surface of their plasma membranes. This coating consists of several carbohydrate moieties of membrane glycolipids glycoproteins, which serve as backbone molecules for support. Generally, the carbohydrate portion of the glycolipids found on the surface of plasma membranes helps these molecules contribute to cell-cell recognition, communication, and intercellular adhesion. The glycocalyx is a type of identifier that the body uses to distinguish between its own healthy cells and transplanted tissues, diseased cells, or invading organisms. Included in the glycocalyx are cell-adhesion molecules that enable cells to adhere to each other and guide the movement of cells during embryonic development. plays a major role in the regulation of endothelial vascular tissue, including the modulation of red blood cell volume in capillaries The slime on the outside of a fish is an example of glycocalyx.
Prostaglandins
a group of bioactive, hormone-like chemicals derived from fatty acids that have a wide variety of biological effects including roles in inflammation, platelet aggregation, vascular smooth muscle dilation and constriction, cell growth, protection of from acid in the stomach, and more
Eukaryotic species
a group of closely related organisms that breed among themselves
azoles
a group of drugs used to treat fungal infections by inhibiting ergosterol synthesis
Reactive Oxygen Species (ROS)
a group of extremely reactive peroxides and oxygen-containing radicals that may contribute to cellular damage; the body produces them because in minute doses they are beneficial
Reactive Oxygen Species (ROS)
a group of metabolites produced by the body during metabolism, such as reactive peroxides and oxygen-containing radicals that may contribute to cellular damage EXAMPLE When someone eats a big meal, during metabolism, their mitochondria will produce ROS such as superoxides (O2^-) and hydrogen peroxides (H2O2). These products can damage the cells via double-strand breaks and base modification. The body creates ROS even though it can harm the body because in certain quantities they are beneficial.
syndrome
a group of symptoms and signs which indicate a specific disease
immune system
a host defense system comprised of many biological structures and processes within an organism that protects against disease The host uses both innate and adaptive mechanisms to detect and eliminate pathogens. comprised of things such as cells, organs, cytokines FUNCTIONS > Defense against invading microorganisms > Removes damages tissue > Identifies and destroys abnormal body cells and pathogens
hygiene hypothesis
a hypothesis that suggests the environments of Western children are unnaturally clean, dramatically decreasing their exposure to routine microorganisms and that the increasing allergies among children are the result of decreased exposure to such microbes
spliceosome
a large and complex molecular machine found primarily within the nucleus of eukaryotic cells that splices RNA by releasing introns from the moleciule and joining the two adjacent exons. comprised from small nuclear RNAs (snRNA) and approximately 80 proteins. ANALOGY: a film editor, who selectively cuts out irrelevant or incorrect material from the initial film and sends the cleaned-up version to the director for the final cut.
inflammation
a localized response to an injury or to the destruction of tissues •Four signs and symptoms: redness, swelling (edema), pain, heat •Destroys injurious agent or limits its effects on the body •Repairs and replaces tissue damaged by the pathogen •causes acute-phase proteins to be produced by the liver that cause vasodilation and increased permeability of blood vessels
Cytokines
a loose classification of small proteins secreted by cytotoxic T cells to aid in antigen destruction; very important in the process of cell-signaling; they are chemical messengers produced in response to a stimulus TYPES any of a number of substances, such as interferons, interleukins, and growth factors, which are secreted by certain cells of the immune system and have an effect on other cells. •Interleukins: cytokines between leukocytes •Chemokines: induces the migration of leukocytes •Interferons (IFNs): interfere with viral infections of host cells •Tumor necrosis factor (TNF): involved in the inflammation of autoimmune diseases (a condition in which your immune system mistakenly attacks your body) •Hematopoietic cytokines: controls the stem cells that develop into red and white blood cells
cytokines
a loose classification of small proteins which are secreted by certain cells (including lymphocytes) of the immune system and affect other cells via cell signaling feature receptors They regulate the intensity and duration of immune responses. FUNCTION They modulate the balance between humoral and cell-based immune responses and regulate the maturation, growth, and responsiveness of particular cell populations. Some can enhance or inhibit the action of other cytokines.
enzyme activity
a measure of the ability of an enzyme to catalyze a specific reaction INFLUENCING FACTORS •Temperature Higher temperatures increase enzymatic activity until the temperature that denatures proteins is met. •pH 5.0 pH is the most optimal too extreme pH will result in denature •Substrate concentration Increasing the concentration of the substrate will increase the activity until all of the available enzymes are occupied. When it's high (saturation), the enzyme catalyzes at its maximum rate. •Inhibitors
Thykaloid
a membrane system found within chloroplasts that contains the components for photosynthesis
viral envelope
a membrane that surrounds the capsid of a virus Viruses can't create their own membrane; Instead viral envelopes come from hosts. 1.) A virus injects its capsid into a host. 2.) The capsid releases its nucleic acids. 3.) The host synthesizes the virus's strand, creating components needed to create a new virus. > Such as capsid-proteins, glycoproteins, and a copy of the virus's genome 4.) A "new" virus is created, taking portions of the host's plasma membrane. 5.) The "new" virus(s) exits the host.
Pentose Phosphate Pathway (PPP) (phosphogluconate pathway) (hexose monophosphate shunt)
a metabolic pathway parallel to glycolysis. It generates NADPH, pentoses (5-carbon sugars), and ribose 5-phosphate (a precursor for the synthesis of nucleotides). The pentose phosphate pathway does involve oxidation of glucose, but its primary role is anabolic rather than catabolic. The pathway is especially important in red blood cells (erythrocytes). There are two distinct phases in the pathway: 1.) oxidative phase: NADPH is generated 2.) synthesis of 5-carbon sugars: non-oxidative For most organisms, the pentose phosphate pathway takes place in the cytosol; in plants, most steps take place in plastids. •Uses pentoses and produces NADPH •occurs simultaneously with glycolysis pentose: 5-carbon sugar produced from PPP and is an important intermediate used in the synthesis of nucleic acids, glucose from CO2 in the photoshythesis and certain amino acids
Entner-Doudoroff pathway (ED Pathway)
a metabolic pathway that is most notably in Gram-negative bacteria, some Gram-positive bacteria and archaea. Glucose is the starting product and, through a series of enzyme assisted chemical reactions, is catabolized into pyruvate. evidence supports the use of this pathway in cyanobacteria, ferns, algae, mosses, and plants •Produces NADPH and ATP •Does not involve glycolysis •Occurs in Pseudomonas, Rhizobium, and Agrobacterium
broth dilution test
a method of determining the minimal inhibitory concentration by using serial dilutions of an antimicrobial drug • used to determine the MIC and MBC of an antimicrobial drug • The test organism is placed into the wells of a tray containing dilutions of a drug; then the growth is determined
resistance
a microbe can resist antibiotics by • the enzymatic destruction or inactivation of the drug • prevention of penetration to the target site within the microbe • alteration of the drug's target site • Rapid efflux (ejection) of the antibiotic • Variations of mechanisms of resistance
plasma membrane
a microscopic membrane of lipids and proteins that forms the external boundary of the cytoplasm of a cell or encloses a vacuole and regulates(selectively-permeable) the passage of molecules in and out of the cytoplasm •Similar in structure to prokaryotic cell membranes •Phospholipid bilayer •Integral and peripheral proteins •Selective permeability •Simple diffusion, facilitated diffusion, osmosis, active transport Differences in structure •Sterols—complex lipids •Carbohydrates—for attachment and cell-to-cell recognition •Endocytosis: phagocytosis and pinocytosis -Phagocytosis: pseudopods extend and engulf particles -Pinocytosis: membrane folds inward, bringing in fluid and dissolved substances
5' cap
a modified form of guanine nucleotide added onto the 5' end of a pre-mRNA molecule helps *protect the mRNA* from degradation of things such as enzymes helps ribosomes *attach* to the 5' end of the mRNA
DNA probe
a molecule labeled with a radioactive isotope, dye, or enzyme that is used to locate a particular sequence or gene on a DNA molecule • This works because of complimentary base pairing
Measles (Rubeola)
a negative sense RNA virus that causes cough, coryza, and conjunctivitis with photophobia (See chapter 13 for NEGATIVE STRAND)
Emerging infectious diseases (EIDs)
a new or changing disease that is increasing or has the potential to increase in incidence in the future •Most are zoonotic, of viral origin, and likely to be vector-borne Contributing factors include: •Genetic recombination (Escherichia coli O157 and avian influenza (H5N1)) •Emerging new strains (Vibrio cholerae O139) •Widespread use of antibiotics and pesticides This encourages antibiotic-resistant strains. •Changes in weather patterns (Hantavirus) •Modern transportation (Chikungunya (dengue) and West Nile virus) •Ecological disasters, including war and expanding human settlement (Coccidioidomycosis) •Animal control measures (Lyme disease) •Public health failure (Diphtheria)
Purine
a nitrogenous base with a double-ring structure; *adenine or guanine* too wide; must pair with a pyrimidine -found in DNA and RNA
pyrimidine
a nitrogenous base with a single-ring structure found in DNA and RNA; *thymine, cytosine, or uracil* too small; must pair with a purine
Photon
a particle of electromagnetic radiation having zero mass and carrying a quantum of energy. (a particle of light) When photons hit a substance, they can be: - Reflected (i.e. a mirror) - Transmitted (i.e. glass) - Absorbed (i.e. darker clothes) Photosynthesis occurs because plants are able to absorb certain colors.
Eosinophils
a phagocytic (meaning toxic against parasties and helminths) granulcyte containing granules that are readily stained by eosin
Neutrophils
a phagocytic (meaning toxic against parasties and helminths) granulcyte that engulfs invading microbes and contributes to the nonspecific defenses of the body against disease; works in the "early stages" of infection DEVELOPMENT Neutrophils are the most common type of leukocyte and play a vital role in policing the body against microbial invasion
melanin
a pigment that gives the skin color
toxin
a poison that can harm an organism (This includes proteins) •Produce fever, cardiovascular problems, diarrhea, and shock RELATED TERMS •Toxigenicity: ability of a microorganism to produce a toxin •Toxemia: presence of toxin in the host's blood •Intoxications: presence of toxin without microbial growth
colony
a population of cells arising from a single cell or spore or from a group of attached cells •A pure culture contains only one species or strain •A colony is formally referred to as a colony-forming unit (CFU) •The streak plate method is used to isolate pure cultures
Immortalised cell lines
a population of cells from a multicellular organism which would normally not proliferate indefinitely but due to mutation lose contact inhibition and instead can keep undergoing division (cancerous) • These kinds of cells can be intentionally engineered. • The cells can be grown for prolonged periods in vitro. • Stem cells can also divide indefinitely, but unlike immortal cells, this is a normal part of the development of a multicellular organism.
climate and weather
a predisposing factor that can make the body more susceptible to disease Climate: the prevailing long term weather conditions Weather: the short term atmospheric, aquatic conditions such as temperature, precipitation, wind, and sunlight "Climate is what you expect, weather is what you get."
Imiquimod (Aldara)
a prescription medication that acts as an immune response modifier by promoting the production of interferons • used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis • brand name: Aldara
Autoclave
a pressure chamber used to perform sterilization; requires elevated temperature and pressure in relation to ambient pressure/temperature. used to sterilize articles via steam under pressure and/or dry heat •IDEAL SETTINGS: 121 Celcius at 15 psi for 15 minutes •Kills all organisms and endospores •Steam must contact the item's surface. •Large containers require longer sterilization times •Test strips are used to indicate sterility
contact inhibition
a process that stops additional cell growth when cells become crowded NORMAL CELLS stop dividing when they come into contact with each other. CANCER CELLS keep dividing, piling on top of each other.
Acid-fastness
a property of Mycobacterium species in which cells stained with the dye basic fuchsin resist decolorization with acidic alcohol Acid-fastness is a physical property of certain bacterial and eukaryotic cells in which they exhibit resistance to decolorization by acids
Perforin
a protein released by cytotoxic T cells that contact with their target cells This protein forms a complex that creates pores (holes) in the target cell membrane that contribute to cell killing by lysis when the taget cell subsequently fills with fluids and provide an entry-point for granzymes
Antigen
a protein that, when introduced in the blood, triggers the production of an antibody
Granzyme
a protein-digesting enzyme contained in the granules of natural killer (NK) cells and cytotoxic T cells that, when released, attacks infected target cells, causing them to undergo apoptosis (self-destruction) • often used in tangent with perforin
wheal
a rapid inflammatory reaction that causes raised red skin lesions due to interstitial fluid
Prontosil (1932)
a red dye that contains sulfa molecule; began the practice of treating used for treating streptococcal infections with drugs
Biosaftey levels
a set of biocontainment precautions required to isolate dangerous biological agents in an enclosed laboratory facility. The levels of containment range from the lowest biosafety level 1 (BSL-1) to the highest at level 4 (BSL-4). BSL-1: no special precautions; basic teaching labs BSL-2: lab coat, gloves, eye protection BSL-3: biosafety cabinets to prevent airborne transmission BSL-4: sealed, negative pressure; "hot zone" •Exhaust air is filtered twice through HEPA filters
Anaphylaxis (Type I) hypersensitivity
a severe response to an allergen in which the symptoms develop quickly, and without help, the patient can die within a few minutes PROCESS 1.) Antigens induce IgE (antibody) production 2.) IgE attaches to mast cells and basophils • occurs minutes after someone who is sensitized to an antigen is re-exposed to that antigen 3.) Mast cells and basophils undergo degranulation, which releases mediators such as • Histamine: increases the permeability of blood capillaries • Leukotrienes: cause prolonged contraction of smooth muscles • Prostaglandins: affect smooth muscle and increase mucus secretion
negative stain
a simple stain that stains the background but leaves the bacteria unstained 1.) nigroson 2.) use the inocculation loop to innoculate bacteria example: B. Cereus on one edge, abd S. Lutea on the opposite side 3.) Take another slide and slide it across the surface with the bacteria and the nigrosin. 4.) Air dry
syncytium
a single cell or cytoplasmic mass containing several nuclei, formed by fusion of cells or by division of nuclei
virus
a small infectious agent that replicates only inside the living cells of an organism. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea.
corepressor
a small molecule that cooperates with a repressor protein to switch an operon "off"
microRNA (miRNA)
a small, non-coding, single-stranded RNA molecule generated from a double-stranded RNA precursor; the miRNA associates with one or more proteins in a complex. responsible for gene silencing (deactivating mRNA strands so that genes aren't expressed) > base-pairs with an mRNA section to make it double-stranded > Double-stranded RNA is enzymatically destroyed, preventing the production of a protein (translation).
Group translocation
a special form of active transport that occurs exclusively in prokaryotes, the substance is chemically altered during transport across the membrane. requires a transporter protein and phosphoenolpyruvic acid (PEP); the substance is altered as it crosses the membrane
Retroviridae
a species of RNA Oncogenic Virus Viral RNA is transcribed to DNA (reverse transcriptase), which can integrate into host DNA •HTLV-1 and HTLV-2 cause adult T-cell leukemia and lymphoma
metabolite
a specific product of a substance, formed by chemical processes in the body
methylene blue
a staining dye/indicator that interacts with nucleic acid molecules and proteins, turning them to a very dark blue color
Ergosterol
a steroid protein found in the cell membrane of fungi; similar in configuration to adrenal hormones and testosterone ANTI-FUNGAL DRUGS • Agents that affect fungal sterols can interrupt the synthesis of ergosterol, making the membrane excessively permeable • agents that affect fungal cell walls can inhibit the synthesis of beta-glucan • Agents inhibiting nucleic acids, such as Flucytosine, can cause a cytosine analog, which interferes with RNA synthesis
nucleoside
a structure of a nitrogenous base with a sugar attached without any phosphate
cofactor
a substance (other than the substrate) whose presence is essential for the activity of an enzyme.
antibiotic
a substance produced by a microbe that, in small amounts, inhibits another microbe
pseudomurein
a substance similar to peptidoglycan that is found in the cell wall of archaea
inhibitor
a substance that slows down or stops a chemical reaction TYPES COMPETITIVE: binds to the active site, directly blocking the substrate from binding to the enzyme NON-COMPETITIVE: binds to an allosteric site, indirectly preventing the substrate from binding to the enzyme. This is because the enzyme changes shape when the non-competitive inhibitor binds.
indirect contact transmission
a susceptible person is infected by contact with a fomite (contaminated surface) rather than the reservoir itself.
Rh blood group system
a system that classifies blood cells based on presence or absence of the "D" antigen on the RBC membrane TYPES RH positive: D antigen is present; no anti-D antibodies in the plasma RH negative: D antigen is absent; no anti-D antibodies in the plasma unless the RH negative blood has been exposed to RH positive blood • The presence of D antigens causes RH negative blood to create anti-D antibodies Rh(D) status of an individual is normally described with a positive or negative suffix after the ABO type
focal
a systemic infection that began as a local infection
Restriction Fragment Length Polymorphisms (RFLPs)
a technique that exploits variations in homologous DNA sequences, known as polymorphisms, in order to distinguish individuals, populations, or species or to pinpoint the locations of genes within a sequence. The term may refer to a polymorphism itself, as detected through the differing locations of restriction enzyme sites, or to a related laboratory technique by which such differences can be illustrated. In RFLP analysis, a DNA sample is digested into fragments by one or more restriction enzymes, and the resulting restriction fragments are then separated by gel electrophoresis according to their size.
streak plate method (streaking)
a technique used to isolate a pure strain from a single species of microorganism, often bacteria. Samples can then be taken from the resulting colonies and a microbiological culture can be grown on a new plate so that the organism can be identified, studied, or tested. The streaking is done using a sterile tool, commonly an inoculation loop. The inoculation loop is first sterilized by passing it through a flame. When the loop is cool, it is dipped into an inoculum such as a broth or patient specimen containing many species of bacteria. The inoculation loop is then dragged across the surface of the agar back and forth in a zigzag motion until approximately 30% of the plate has been covered. The loop then is re-sterilized and the plate is turned 90 degrees. Starting in the previously streaked section, the loop is dragged through it two to three times continuing the zigzag pattern. The procedure is then repeated once more being cautious to not touch the previously streaked sectors. Each time the loop gathers fewer and fewer bacteria until it gathers just single bacterial cells that can grow into a colony. The plate should show the heaviest growth in the first section. The second section will have less growth and a few isolated colonies, while the final section will have the least amount of growth and many isolated colonies.
conjugation
a temporary binding of two organisms for the purpose of DNA transfer • fusion (high heat) of plama membranes with a conjugation pili
Dysbiosis
a term denoting a microbial imbalance or maladaptation on or inside the body, such as an impaired microbiota EXAMPLES • Antibiotic therapy kills normal gut microbiota, causing Clostridium difficile (C-diff) to proliferate • can cause irritable bowel diseases such as ulcerative colitis and Crohn's disease
LD50 (lethal dose)
a term that denotes the amount of a chemical necessary to kill 50% of the test subjects, which are usually animals •This term is associated with measuring the potency of a toxin This term is a ratio typically expressed as "nanogram of the toxin" per "kilogram of the host's body mass" EXAMPLE: mice Botulinum is a toxin that has an LD50 of 0.03 ng/kg when in contact with the mice. The LD50 of Shiga toxin is 250 ng/kg with the mice. The LD50 of Staphylococcal enterotoxin is 1350 ng/kg with the mice. CONCLUSION The most dangerous of the listed toxins for mice is botulinum because it only requires 0.03 nanograms of botulinum for every kilogram of the mice to kill 50 % of the mice population. This is the lowest LD50 of the listed toxins.
valence
a term that denotes the number of antigen-binding sites an antibody possesses. •EXAMPLE: Bivalent antibodies have two binding sites
ID50 (infectious dose)
a term which refers to the number of microbes that must enter the body to establish infection in 50% of test subjects, usually animals • This term denotes the virulence (degree of pathogenicity) of a microbe. Viruses typically have a much lower ID than bacteria. EXAMPLE: Bacillus Anthracis Bacillus Anthracis causes anthrax, which is a bacterial disease that in humans causes severe skin ulceration or pneumonia. When this bacteria enters through the skin, the ID50 is expected to be 10 to 50 endospores. When it's Inhaled, the ID50 is 10,000 to 20,000 endospores. When it's ingested, the ID50 is 250,000 to 1,000,000 endospores. CONCLUSION Therefore, the "easiest" way to be afflicted with anthrax from this bacteria is through the skin, because the number of bacteria required to cause anthrax tends to be the lowest. Cutaneous (skin) anthrax is easier to acquire than any of the other forms.
E-test
a test for microbial growth consisting of strips (instead of disks) that change colors, indicating the amount of microbial growth • The intersection of the elliptical (oval shaped) zone of inhibition with the strip indicates the MIC
disk diffusion method
a test of the antibiotic sensitivity of bacteria. It uses antibiotic discs to test the extent to which bacteria are affected by those antibiotics. In this test, wafers containing antibiotics are placed on an agar plate where bacteria have been placed, and the plate is left to incubate. If an antibiotic stops the bacteria from growing or kills the bacteria, there will be an area around the wafer where the bacteria have not grown enough to be visible. This is called a zone of inhibition.
disk diffusion
a test that measures the resistance of microbes to antibiotics; paper disks containing the antibiotics are placed on inoculated agar plates zone of inhibition: region around a chemical saturated disc, where bacteria are unable to grow due to adverse effects of the compound in the disc.
chromosome
a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
Antigen
a toxin, protein, or other foreign substance that induces an immune response in the body, especially the production of antibodies. usually in the blood
Meiosis
a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores (sex cells) SIDENOTE: Diploids create haploids (via PMATC). Haploids, such as sex cells use (PMATC) to transform into four unique (sex) cells.
Meiosis
a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.
metal ions
a type of cofactor which bridges the enzyme and substrate together when combined with a protein becomes a catalyst
coenzyme
a type of cofactor; non-protein organic complex Used to activate apoenzymes
type O blood
a type of erythrocyte (red blood cell) that doesn't feature any antigens on their surface but features anti-A and anti-B antibodies in the plasma • anti-B antibodies: cause an immune response that attacks cells with B-antigens • anti-A antibodies: cause an immune response that attacks cells with B-antigens Cytotoxic (Type II) Hypersensitivity • Can receive from blood type O only • Can donate to blood type A, B, and AB (UNIVERSAL DONOR)
type A blood
a type of erythrocyte (red blood cell) that has A-antigens on their surface and features anti-B antibodies in the bloodstream • anti-B antibodies: cause an immune response that attacks cells with B-antigens Cytotoxic (Type II) Hypersensitivity • Can receive from blood types A and O • Can donate to blood type A and AB
type AB blood
a type of erythrocyte (red blood cell) that has B-antigens and A-antigens on their surface and doesn't feature A or B antibodies the bloodstream Cytotoxic (Type II) Hypersensitivity • Can receive from blood type A, B, AB, and O (Universal recipient) • Can donate to AB
type B blood
a type of erythrocyte (red blood cell) that has B-antigens on their surface and features anti-A antibodies in the bloodstream • anti-A antibodies: cause an immune response which attacks cells with A-antigens Cytotoxic (Type II) Hypersensitivity • Can receive from blood type B and O • Can donate to blood type B and AB
Thermophile
a type of extremophile that thrives at relatively high temperatures; between 41 C to 122 °C (106 and 252 °F) •Optimum growth temperature of 50 Cto 60 C •Found in hot springs and organic compost Hyperthermophiles•Optimum growth temperature is greater than 80 C Most are archaea Thermophiles can survive at high temperatures, whereas other bacteria would be damaged and sometimes killed if exposed to the same temperatures. The enzymes in thermophiles function at high temperatures. Some of these enzymes are used in molecular biology. found in various geothermally heated regions of the Earth, such as hot springs like those in Yellowstone National Park and deep sea hydrothermal vents, as well as decaying plant matter, such as peat bogs and compost. "Thermophile" is derived from the Greek, meaning heat-loving
small nuclear ribonucleoproteins (snRNPs)
a type of protein that combines with other proteins to form a spliceosome, which removes introns and splice exons together
conjugated vaccines
a type of vaccine that features the engineered combination of a desired antigen with a protein that boosts the immune response; weak antigens are mixed with strong antigens that function as a carrier so that the immune system has a stronger response to the weak antigen. • Used for diseases in those (usually children) with poor immune response to capsular polysaccharides (polysaccharides combined with diphtheria or tetanus toxoid) • The successful vaccine for Haemophilus incluenzae type b)
marcophage
a type of white blood cell that ingests and kills pathogens
phagocytes
a type of white blood cell that ingests invading microbes
lytic cycle
a viral reproductive cycle in which copies of a virus are made within a host cell, which then bursts open (lysis), releasing new viruses •Phages such as bacteriophages cause lysis and death of the host cell NOW OR LATER? The difference between lysogenic and lytic cycles is that in lysogenic cycles the spread of the viral DNA occurs through the usual prokaryotic reproduction, whereas a lytic cycle is more immediate in that it results in many copies of the virus being created very quickly and the host cell is destroyed. LYSOGENIC: The infection occurs later because the lysogenic virus subtly incubated itself before releasing. LYTIC: The infection occurs relatively quickly because lytic viruses don't give a f*ck about stealth. They go in guns blazing.
human immunodeficiency virus (HIV)
a virus that attacks the immune system, causes a deficiency in T-cells, and generally leads to AIDS • can be active or latent STAGES / PHASES Phase 1: appears as asymptomatic (no symptoms) or lymphadenopathy (lymph nodes become swollen) Phase 2: The number of CD4+ T cells (helper) in the body decline steadily. Only a few infected cells release the virus, so only a few serious symptoms appear. • (persistent infections, fever, and oral leukoplakia) Phase 3: AIDS develops; and the CD4+ is count drops below 200 cells/μl • (often measured as an indicator condition) RESISTANCE • Initially, the immune system is strong and effective. • CTLs suppress viral growth. • If HIV establishes enough latently infected CD4+ T cells, it's impossible to clear the infection. • Currently, (2020) the world is trying to make a vaccine.
Cowpox
a virus that behaves as a milder version of smallpox. The immune system can adapt to this disease and in turn develop an immunity against smallpox without having to be inoculated with smallpox. • In the late 18th century, milkmaids caught this from the cows they milked.
cytopathic effect (CPE)
a visible effect on a host cell, caused by a virus, that may result in host cell damage or death
folic acid
a vitamin needed for nucleic acid and protein synthesis • found in leafy green vegetables
Killed/inactivated vaccines
a whole cell or intact virus preparation in which the microbes are dead or preserved and cannot multiply but are still capable of conferring immunity • viruses are inactivated • bacteria are killed • require repeated booster doses • Induce mostly humoral immunity
Mucicarmine stain
a yellowish differential stain capable of differentiating Cryptococcus neoformans
Motility Media
ability for bacteria to ferment mannite and produce N2 gas; indicate movement of organism
Indole
ability for bacteria to split indole off from tryptophan positive= red ring on top after adding Kovac solution negative=absence of color after Kovac solution dropped
gene regulation
ability of an organism to control which genes are transcribed in response to the environment Every type of cell in an organism contains the same genome. Gene Regulation refers to the process in which the cell decides which aspects of the genome are relevant for the purpose of the cell. SIMILE: The genome is a cookbook. The different types of cells are different cooks deciding which recipe they need.
Pathogenicity
ability to cause disease
contagious
able to be transmitted easily or rapidly from one host to another
Disseminated Intravascular Coagulation (DIC)
abnormal activation of the proteins involved in blood coagulation, causing small blood clots to form in vessels and cutting off the supply of oxygen to distal tissues
fever
abnormally elevated body temperature • Hypothalamus is normally set at 37°C • Cytokines cause the hypothalamus to release prostaglandins that reset the hypothalamus to a higher temperature • Body constricts the blood vessels, and shivering occurs (which raises body temperature) • As body temperature falls, vasodilation and sweating occurs
raised (elevation)
above agar surface with center and edges having an even height
convex (elevation)
above agar surface with center slightly higher than edges
pulvinate (elevation)
above agar with center much higher than edges
Leukotrienes
activates and attracts neutrophils and eosinophils; also causes prolonged contraction of smooth muscles
primary infection
acute infection that causes the initial illness
Interleukins (ILs)
adaptive immune system cytokines that signal among leukocytes; They promote the development and differentiation of T and B lymphocytes, and hematopoietic cells
Cellular immunity (cell-mediated immunity)
adaptive immunity in which T lymphocytes are produced. They mature in the thymus and recognize antigenic peptides that are discovered and processed by phagocytes. This kind of immunity fights antigens found in host cells rather than outside of them. • viruses, some fungi, and parasites • T cell receptors (TCRs): receptors on the surface of T cell that connect with antigens; this occurs so that the T cells secrete cytokines instead of antibodies
DNA polymerase
adds nucleotides to the growing DNA strand •In the 5' to 3' direction DNA POLYMERASE III •Leading strand is synthesized continuously •Lagging strand is synthesized discontinuously, creating Okazaki fragments DNA POLYMERASE I •removes RNA primers; Okazaki fragments are joined by the DNA polymerase and DNA ligase
hyphal
adjective describing the root-like structures of fungi
voltage control
adjusts the intensity of the light transmitted to the specimen
Systemic (generalized)
affecting the entire body, rather than a single organ or body part. For example, systemic disorders, such as high blood pressure, or systemic diseases, such as the flu, affect the entire body. An infection that is in the bloodstream is called a systemic infection.
hay fever (allergic rhinitis)
allergic disease of the mucous membranes in the nose and the upper respiratory passages • caused by exposure to pollen from grass, weeds, flowers, and other allergenic substances
brightfield
allows direct light into eye w/o being detected by plate
differential media
allows growth of several types of microbes and displays visible differences among those microbes
phage conversion
alteration of the phenotype (observable traits; genotype refers to the genetic make-up responsible for the phenotype) of a host cell by a lysogenization
proteins
amino acids convert to intermediates of glycolysis and citric acid cycle
Potency
amount of drug required to achieve a desired effect (Compare with efficacy, the ability of a drug to achieve a desired effect)
metabolic activity
amount of metabolic product is proportional to the number of bacteria
Protozoa
an *informal* term for *single-celled eukaryotes* that are either free-living or *parasitic*, which feed on organic matter such as other microorganisms, organic tissues, and debris a type of *protist* (one of the six kingdoms) often possess animal-like behaviors, such as *motility* and *predation*, and *lack* a *cell wall*, as found in plants and many *algae*. can also *move independently* and feed by *heterotrophy*
sympathomimetic
an agent that mimics the effects of the sympathetic nervous system
Flucytosine
an analog that's often detrimental to fungi and corresponds to cytosine • fungi will mistake flucytosine for cytosine, causing problems with their RNA synthesis
Uncoating
an animal virus's nucleic acid is released from the capsid once the binding of the spikes of the virus and host's cell membrane occurs The spikes act like a key to a lock when it binds to specific receptors on the host's cytoplasmic cell membrane. (The host's membrane is deceived into thinking the spikes are something that it should take by opening its membrane.)
Penicillin (1928)
an antibiotic discovered by Alexander Fleming (1881-1955) that inhibits gram-positive pathogens by inhibiting cell wall synthesis • contains a β-lactam ring • can be differentiated into types based on the chemical side chains attached to the ring • prevent the cross-linking of peptidoglycans, interfering with cell wall construction (especially gram-positives) HISTORY Fleming observed that the bacteria in proximity to the mold colonies were dying because of the dissolving and clearing of the surrounding agar gel. He was able to isolate the mold and identified it as a member of the Penicillium genus. He found it to be effective against all Gram-positive pathogens, which are responsible for diseases such as scarlet fever, pneumonia, gonorrhoea, meningitis and diphtheria. He discerned that it was not the mold itself but a secretion it had produced that had killed the bacteria. He named the secretion "penicillin". • 1940: first clinical trials of penicillin
IgG
an antibody (immunoglobulin) and monomer; composes 80% of serum antibodies If this is the first time the antigen has been encountered, a primary immune response is mounted. Usually there is a delay of several days, then IgM antibody is produced, followed by a switch to IgG antibody production. The initial IgM molecules bind the antigen weakly, but the subsequent IgG molecules are much better targeted. IgG continues to be produced long after the encounter with the antigen, providing long-lasting immunity. (Secondary Response) Fix complement Cross placenta Half-life = 23 days • found in blood, lymph, and intestine • enhances phagocytosis; neutralize toxins and viruses; protects fetus and newborn
Sulfanilamide
an antimetabolite that competes with para-aminobenzoic acid (PABA) for an enzyme, stopping the synthesis of folic acid • inhibit the folic acid synthesis needed for nucleic acid and protein synthesis • competitively bind to an enzyme needed for PABA production, a folic acid precursor
Grave's disease
an autoimmune disorder that causes hyperthyroidism, or overactive thyroid; the immune system attacks the thyroid and causes it to make more thyroid hormone than the body needs. • The thyroid is a small, butterfly-shaped gland in the front of your neck. • This condition is more common in women under age 40. • Symptoms include anxiety, hand tremor, heat sensitivity, weight loss, puffy eyes and enlarged thyroid. Treatment includes medications. • Sometimes the thyroid is removed.
3' poly-A tail
an enzyme adds 50-250 adenine (A) nucleotides onto the 3' end of the pre-mRNA strand the tail functions to *move the mRNA* out of the nucleus and into the cytoplasm and appears to protect the mRNA strand from degradation. -eukaryotes
Lysozyme
an enzyme found in saliva and sweat and tears that destroys the cell walls of certain bacteria; involved with perspiration (breathing) (compare to a lysosome, an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane.)
Kinase
an enzyme that catalyzes the transfer of a phosphate group from ATP to a specified molecule and digests protein clots
kinase
an enzyme that catalyzes the transfer of a phosphate group from ATP to a specified molecule.
Keratinocytes
an epidermal cell that produces keratin, a structural protein
incident
an event or occurrence in which a number of people develop a disease during a particular time period (incidence)
Hypersensitivity
an exaggerated response by the immune system to a particular substance TYPES • anaphylactic • cytotoxic • immune complex • delayed cell-mediated Hygiene hypothesis: a theory that suggests that limiting exposure to pathogens may lower immune tolerance and the ability to cope with harmless antigens
Membrane-disrupting toxins
an exotoxin that cause the host cell to lyse by disrupting plasma membranes
genotoxins
an exotoxin that damages DNA (causing mutations, disrupting cell division, and leading to cancer)
Meselson-Stahl Experiment
an experiment of Matthew Meselson and Franklin Stahl in 1958 which supported Watson and Crick's hypothesis that DNA replication was semiconservative. (Nitrogen is found in the nitrogenous bases of each nucleotide.) *BACKGROUND* Meselson and Stahl sought to understand how and why the daughter DNA strand was different than the parent strand by creating DNA molecules in which the normal nitrogen atoms of the DNA molecules were replaced with heavier isotopes of nitrogen. They moved their new DNA molecules, which contained only the heavier nitrogen isotopes, to an environment which was heavily saturated with the "normal" lighter nitrogen atoms. This was done so that each following generation would be altered in such a way that the resulting daughter strands would only possess the "normal" nitrogen atoms. Since the isotopes of nitrogen were heavier and only present in the parent strands, it was a factor which could be used to distinguish between the two types of strands. This experiment relied upon a centrifuge, which tries to move the heavier strands to one side of a test tube, and the lighter strands to the other. But the centrifuge cannot split the strands apart from the molecule, so the DNA must move to a position in the test tube based on the average density of the strands. They would use the centrifuge each time the DNA replicated to study the differences of nitrogen-isotopes presence of each generation. The presence of each type of nitrogen atom in each DNA molecule directly correlated to the position of the DNA in the test tube. *HYPOTHESIS* Meselson and Stahl used their experiment as a basis to validate or disprove three of the most eminent theories of DNA replication at the time: SEMI-CONSERATIVE, CONSERVATIVE, and DISPERSIVE replication. *RESULTS* Note that DNA molecules which only possess "normal" nitrogen atoms would be moved to the top of the test tube by the centrifuge. Also note that when DNA molecules replicate, splitting the two strands of the molecule apart, each of the two strands creates and bonds with another strand that contains the nitrogen of the surrounding environment. In this experiment, each newly created strand is entirely made up of "normal"(lighter) nitrogen atoms. PARENTAL GENERATION Initially, after measuring the location of the DNA with the centrifuge, all of the DNA collected to the bottom of the tube. This is because none of the DNA replicated, so every strand was composed of the same heavy isotopes. GENERATION 1 (F1) When the DNA replicated once, the centrifuge moved the DNA in such a way that a "pellet" formed in the middle of the tube. This indicated that this generation of DNA was less dense than the parental generation, but must have been more dense than DNA molecules which possess only strands containing "normal" nitrogen atoms. This disproves the CONSERVATIVE DNA REPLICATION theory since this generation didn't possess the same density as the parental generation or form a pellet at the top of the tube, meaning that some of the daughter stands must have been different in some way and that the molecule was a combination of both "normal" and "heavy" nitrogen containing strands. Every F1 DNA molecule was identical, being composed of a strand that only contained "heavy" nitrogen isotopes, and a strand which contained only "normal" nitrogen atoms. GENERATION 2 (F2) This generation produced two pellets. One pellet was located at the top of the test tube. The other pellet was located in the middle again. This is because, in the case of this experiment, when the DNA strands split apart, they create and pair up with a strand which only possesses "normal nitrogen". The F1 Molecules were composed of two distinct strands which separated during DNA replication. Each strand created and bonded with a new strand that was only composed of "normal" nitrogen atoms. This means that the F2 molecules were either composed of two identical strand that only contained "normal" nitrogen, or they were composed of a strand which only contained "normal" nitrogen and a strand which contained "heavy" nitrogen. Since two separate pellets were produced, this experiment disproves the DISPERSIVE DNA REPLICATION theory. The dispersive model predicts that there will only ever be one pellet of a seemingly random density. NOTE: As DNA replication continues, the ratio of DNA molecules which contain only "normal" nitrogen to molecules than contain only "heavy" nitrogen becomes greater. In each generation, the likelihood of finding a DNA molecule with a "heavy" nitrogen strand becomes rarer since the "heavy" strand isn't created; it is only conserved. The "normal" strand however is created by each splitting strand. *INTUITION* Say there is only one DNA molecule in a P generation. This molecule is composed of two "heavy" strands. No matter how many generations elapse, there will only ever be two "heavy" strands total despite the increasing number of molecules which arise in each generation.
microbial growth
an increase in the number of microbes 6-1: describe the requirements for bacterial growth PHYSICAL REQUIREMENTS •pH •Temperature •Osmotic pressure CHEMICAL REQUIREMENTS •Carbon, Nitrogen, sulfur, oxygen and phosphorous •Trace elements •Organic growth factors 6-2 Define colony and describe how pure cultures can be isolated 6-3 Define bacterial growth, including binary fission 6-4 Compare the phases of microbial growth and describe their relation to generation time 6-5 Differentiate direct and indirect methods of measuring cell growth
Healthcare-associated infection (HAI) (nosocomical infection)
an infection acquired within a healthcare setting during the delivery of medical care •Affect 1 in 25 hospital patients •2 million per year infected; 20,000 deaths HAIs result from: •Microorganisms in the hospital environment •Weakened status of the host •Chain of transmission in a hospital •Compromised host: an individual whose resistance to infection is impaired by disease, therapy, or burns
local
an infection in which pathogens are limited to a small area of the body
algae
an informal term for a large, diverse group of *photosynthetic*, *eukaryotic* organisms including: unicellular microalgae (such as Chlorella), diatoms, and multicellular forms (such as the kelp) Most are *aquatic* and *autotrophic* and lack many of the distinct cell and tissue types generally possess *chlorophyll* and *lack* a sterile covering of cells around their reproductive cells. produce oxygen as a by-product of photosynthesis, unlike other photosynthetic bacteria EMINENT EXAMPLES: seaweeds, Charophyta, Spirogyra, and stoneworts
Nucleoid
an irregularly shaped region within the cell of a prokaryote that contains all or most of the genetic material. The length of the DNA chromosome is very large compared to the dimensions of the cell, and so must be compacted to fit. In contrast to the nucleus of a eukaryotic cell, it is not surrounded by a nuclear membrane. Instead, the nucleoid forms by condensation and functional arrangement with the help of chromosomal architectural proteins and RNA molecules as well as DNA supercoiling. The length of a genome widely varies (generally at least a few million base pairs) and a cell may contain multiple copies of it. •Bacterial chromosome: circular thread of DNA that contains the cell's genetic information •Plasmids -extrachromosomal genetic element -carries non-crucial genes (e.g., antibiotic resistance, production of toxins) -replicated independently of chromosomal DNA -can be gained and lost without harming the cell
inducible operon
an operon that inhibits the expression of a gene (off, meaning that transcription doesn't take place) until it's been induced. INDUCED: When a specific small molecule(s), inducer, binds with a regulatory protein
Transcription
an organic process in which a particular segment of DNA is copied into RNA-mostly *mRNA*-by the enzyme RNA polymerase Since the DNA cannot leave the nucleus, this process is necessary to create copies of the DNA sections proteins need. -occurs in the nucleus THREE Consecutive STAGES 1.) Initiation Stage 2.) Elongation Stage 3.) Termintermation Stage •Synthesis of a complementary mRNA strand from a DNA template •Transcription begins when RNA polymerase binds to the promoter sequence on DNA •Transcription proceeds in the 5' to 3' direction; only one of the two DNA strands is transcribed •Transcription stops when it reaches the terminator sequence on DNA
Vector
an organism that does not cause disease itself but which spreads infection by conveying pathogens from one host to another. They transmit disease by two general methods: •Mechanical transmission: physical transfer (example: arthropod carries pathogen on its feet) •Biological transmission: pathogens reproduces in the vector; the vector transmits the disease (via things like bites or feces) EMINENT EXAMPLES •Arthropods, especially fleas, ticks, and mosquitoes •Species of mosquito, for example, serve as vectors for the deadly disease Malaria.
Auxtotroph
an organism that is unable to synthesize a particular organic compound required for its growth mutant that has a nutritional requirement absent in the parent •Use of replica plating
Hyperthermophiles
an organism that thrives in extremely hot environments from 60 °C (140 °F) and greater; a subset of extremophiles Many are also able to withstand other environmental extremes such as high acidity or high radiation levels. (archaea growing at 80 degrees celcius or greater)
chemoheterotrophic
an organism that uses organic molecules as a source of carbon and energy
extremophiles
an organism, archaea, with optimal growth in environmental conditions considered extreme in comparison to the environmental conditions that are comfortable to humans
clostridium
anaerobic gram positive rod shaped bacteria
connective tissue
animal tissue that functions mainly to bind and support other tissues, having a sparse population of cells scattered through an extracellular matrix
antitoxin
antibodies against a specific toxin
Immunogen
antigen that induces an immune response DIFFERENCE FROM AN ANTIGEN An immunogen refers to a molecule that is capable of eliciting an immune response by an organism's immune system, whereas an antigen refers to a molecule that is capable of binding to the product of that immune response. So, an immunogen is necessarily an antigen, but an antigen may not necessarily be an immunogen.
adaptive immunity
antigen-specific immune response; the antigen first must be processed and recognized more complex than an innate immunity. once an antigen has been recognized, the adaptive immune system adapts to the it with specific countermeasures designed to attack that antigen. includes a "memory"; future responses against that specific antigen are more efficient after the initial encounter
Cytokines
antiviral proteins secreted by cytotoxic T cells to aid in antigen destruction
Interferons (IFNs)
antiviral proteins that may act as cytokines; interferon genes can activate and code for interferons, which in turn repress coding genes •types of cytokines produced by cells that have antiviral activity TYPES • IFN-α and IFN-β: produced by cells in response to viral infections; cause neighboring cells to produce antiviral proteins (AVPs) that inhibit viral replication •IFN-y (y: gamma): causes neutrophils and macrophages to kill bacteria
Interferons (IFNs)
antiviral proteins that may act as cytokines; they prevent further viral reproduction (transcription, translation)
cancer
any malignant growth or tumor caused by abnormal and uncontrolled cell division Several types of cancer are caused by viruses. •May develop long after a viral infection •Cancers caused by viruses are not contagious Sarcoma: cancer of connective tissue Adenocarcinomas: cancers of glandular epithelial tissue
texture
appearance of colony -smooth -rough -shiny/wet -mucoid -dry/crusty
margin
appearance of edge of colony
counterstain
application of second stain with a contrasting color to sample for microscopy; safranin is usually used
privileged site
area of transplant or graft that does not stimulate an immune response
Adaptive immunity (specific)
aspect of the immune system in which the body recognizes or adjusts accordingly to foreign substances; the immune system isn't born with this kind of immunity; it learns it. • Acquired through infection or vaccination • Primary response refers to the first time the immune system combats a particular foreign substance • Secondary response: any succeeding interactions with the same foreign substance; the immune system is quicker and more effective due to memory exhibits specificity and memory; recognizes specific foreign substances and produces long-term protection CONTRAST with INNATE IMMUNITY, in which the immune system's countermeasures are already present before infection (the kind of immunity you're born with).
adherence
attachment of a phagocyte to the surface of the microorganism •Toll-like receptors (TLRs) on host cells attach to pathogen-associated molecular patterns (PAMPs) •TLRs bound to PAMPs induce the release of cytokines from the host cell that regulate the intensity and duration of immune responses
Fimbriae
attachment structures on the surface of some prokaryotes; attachment structures on the surface of some prokaryotes
Fimbriae
attachment structures on the surface of some prokaryotes; they are also the "finger" or "fringe like" projections at the end of the fallopian tubes
darkfield
background is light free and objects illuminated by rays reflected from lens system
dry weight
bacteria are filtered, dried, and weighed; used for filamentous organisms
bacteremia
bacteria present in the blood but are not necessarily multiplying ("-emia": denoting a substance present in the blood)
superbugs
bacteria that are resistant to large numbers of antibiotics
fermentation test
bacteria that catabolize carbohydrates or proteins produce acid, which causes pH indicators to change color
Streptococci
bacteria that form a linear chain
Mesophile
bacteria that prefers moderate temperature; thrives best at temperatures between 25 C to 45 C mainly applies to microorganisms; bacteria, archaea and fungi Mesophiles belonging to the domain Bacteria can either be gram-positive or gram-negative. Oxygen requirements for mesophiles can be aerobic or anaerobic. THE THREE BASIC SHAPES > coccus (round) > bacillus (rod) > spiral extremophiles: organisms that prefer extreme environments
Teichoic acids
bacterial copolymers of glycerol phosphate or ribitol phosphate and carbohydrates linked via phosphodiester bonds. found within the cell wall of most Gram-positive bacteria and appear to extend to the surface of the peptidoglycan layer. •Lipoteichoic acid links cell wall to plasma membrane •Wall teichoic acid links the peptidoglycan •Carry a negative charge •Regulate movement of cations •Polysaccharides and teichoic acids provide antigenic specificity They can be covalently linked to N-acetylmuramic acid or a terminal D-alanine in the tetrapeptide crosslinkage between N-acetylmuramic acid units of the peptidoglycan layer, or they can be anchored in the cytoplasmic membrane with a lipid anchor. Teichoic acids that are anchored to the lipid membrane are referred to as lipoteichoic acids (LTAs), whereas teichoic acids that are covalently bound to peptidoglycan are referred to as wall teichoic acids.
Eukaryotic DNA replication
begins at MANY origins of replication on the DNA molecule and proceeds in both directions until the entire chromosome is copied
subacute
between acute and chronic; symptoms and signs that are generally less severe than acute symptoms
single strand binding proteins
bind to the unpaired DNA strands, keeping them from re-pairing
large ribosomal subunit
binds to the tRNA, the amino acids, and the smaller subunit *joins the amino acids together*, forming a polypeptide chain
Hematopoiesis
blood cell formation
rhizoid (form)
borders like tree roots; deeper than filamentous
protein catabolism
breakdown of protein to amino acids PATHWAY Protein (Extracellular proteases) Amino acids (Deamination, decarboxylation, dehydrogenation, desulfurization) Organic acid Krebs cycle MEMORIZE THE DIAGRAM
collagenase
breaks down collagen
axial filaments (endoflagella)
bundles of fibrils that arise at the ends of the cell beneath an outer sheath and spiral around the cell (i.e. flagella found inside the cell); these bundles allow for the movement of spirochetes •Found in spirochetes •Anchored at one end of a cell •Rotation causes cell to move like a corkscrew
Antigen-presenting cells (APC)
calls that process antigens and activate cells of the immune system (by presenting the antigen to the cells that fight infection) TYPES • dendritic cells: They engulf and degrade pathogens and display them to T cells; found in the skin, genital tract, lymph nodes, spleen, thymus, and blood • macrophages: activated by cytokines or the ingestion of antigenic material; these cells migrate to the lymph tissue, presenting antigens to T cells • B leukocytes: create antibodies
viral growth
can cause cytopathic effects in the cell culture •For a virus to multiply it must invade a host cell take over the host's metabolic machinery •One-step growth curve:
Surface-active agents (surfactants)
can decrease surface tension among molecules of a liquid Soap Degerming; emulsification Acid-anionic sanitizers Anions react with plasma membrane Quaternary ammonium compounds (quats) Cations are bactericidal, denature proteins, disrupt plasma membrane
facultative anaerobes
can live with or without oxygen; grow via fermentation or anaerobic respiration (no oxygen)
Predisposing factors of disease
can make a person or group more vulnerable to disease •Gender •Inherited traits (such as the sickle cell gene) •Climate and weather •Fatigue •Age •Lifestyle •Nutrition •Chemotherapy
translucent (texture)
can see through colony
opaque (texture)
can't see under colony
Capsular polysaccharide
capsules made of polysaccharide(s) (polysaccharides combined with the diphtheria toxoid or tetanus toxoid) - Visualized by the India ink technique - Promotes adherence to host cell surfaces and to other bacteria Note that capsules are major virulence factors but are poorly antigenic
NADP+
carrier molecule that transfers high-energy electrons from chlorophyll to other molecules
NADP+
carrier molecule that transfers high-energy electrons from chlorophyll to other molecules Nicotinamide adenine dinucleotide phosphate •Assist enzymes; electron carrier
acid stains
carries a negative charge; anionic eosin nigrosin indian ink Note: Don't stain the bacteria cell wall, only the background.
periods of disease
categorized into 5 distinct stages: 1.) Incubation 2.) Prodromal 3.) illness (climax) 4.) decline 5.) convalescence •Incubation period: interval between the initial introduction of the infection and first signs and symptoms •Prodromal period: the short period after incubation characterized by early, mild symptoms •Period of illness: disease is the most severe •Period of decline: signs and symptoms gradually subside •Period of convalescence: body returns to the state before the disease; recovery
Superantigens
cause an intense immune response due to the release of cytokines from host cells (T cells) They bind directly to MHCII and T-cell receptors simultaneously, activating large numbers of T-cells to stimulate release of IFN-gamma and IL-2 •symptoms include: fever, nausea, vomiting, diarrhea, shock, death
Tetanus (toxin)
causes antagonistic muscles to contract at the same time
IFN-y
causes neutrophils and macrophages to phagocytize bacteria
IgA antibodies
causes phagocytosis by WBCs and prevent pathogens from adhering to mucous membranes
Apoptosis
cell death which occurs intentionally as a normal and controlled part of an organism's growth or development • The immune system kill the body's cells when they are infected to control the spread of viruses. • Blebbing: a process in which cells cut their genome into fragments, causing the membranes to bulge outward
microfold cells (M cells)
cells found in in Peyer's patches that capture and transfer antigens to lymphocytes and antigen-presenting cells (APC) LOCATION These cells are found in • the gut-associated lymphoid tissue (GALT) of the Peyer's patches in the small intestine (gastrointestinal tract) • the mucosa-associated lymphoid tissue (MALT) of other parts of the gastrointestinal tract. FUNCTION These cells initiate mucosal (mucous) immunity, transporting pathogenic microbes and particles (via endocytosis, phagocytosis, or transcytosis) across the epithelial cell layer from the gut to lymphocytes. M cells lack microvilli but, like other epithelial cells, they are characterized by strong cell junctions. This provides a strong and vital physical barrier for defending the gut contents and the immune system of the host. Despite the epithelial barrier, some antigens are able to infiltrate the M cell barrier and infect the nearby epithelial cells or enter the gut.
B cells
cells manufactured in the bone marrow that create antibodies for isolating and destroying invading bacteria and viruses
Prokaryotic
cells that do not have a nucleus or other membrane-bound organelles. -features nucleoid, unbound region which contains DNA
Hybridoma
cells that form through the engineered combination of immortal (cancerous) B cells and normal (antibody-producing) B cells (plasma cells); these cells are designed so that an endless supply of antibodies can be created • These cells produce monoclonal antibodies (Mabs) • These cell lines are "immortal" in the sense that they lack contact inhibition
oogonia
cells that produce primary oocytes by mitotic division during *prenatal development*
Streptobacilli
chains of bacilli
Mutation
change in a DNA sequence that affects genetic information; contributes to cell diversity •Mutations may be neutral, beneficial, or harmful TYPES •Base substitution (point mutation) •Missense mutation •Nonsense mutation •Frameshift mutation
Base mutation (point mutation)
change in one nitrogenous base of DNA
signs
changes in a body as a result of disease or disorder that can be directly measured or observed (Compare with symptoms, which can't be directly measured.)
Plasmodesmata
channels through cell walls that connect the cytoplasms of adjacent cells
portals of entry
characteristic route of a microbe to enter the tissues of the body •Most pathogens have a preferred portal of entry 3 MAIN PORTALS mucous membranes many bacteria and viruses use this portal skin parenteral route (Greek para, "besides" + enteros) "Parenteral" refers to routes outside of the human gastrointestinal tract (GI), such as intravenous routes. This contrasts with "enteral", referring to the nutrition or drug administration through the GI tract. •The microbes are deposited directly into tissues when barriers are penetrated. (punctures, injections, bites, cuts, wounds, and surgery)
redox reactions (oxidation-reduction reactions)
chemical reactions that transfer electrons between reactants •In biological systems, electrons and protons are removed at the same time; equivalent to a hydrogen atom •Biological oxidations are often dehydrogenations
histamine
chemical stored in mast cells that triggers dilation and increased permeability of capillaries.
Antimetabolites
chemicals that prevent cell division by inhibiting formation of substances necessary to make DNA • used in cancer chemotherapy
homologous chromosomes
chromosomes that have the same sequence of genes and the same structure but not necessarily the same alleles; they can undergo synapsis
Curled (margin)
circular
bacterial DNA
circular DNA molecule and its associated proteins; ONE origin of replication, unlike eukaryotic DNA •Most bacterial DNA replication is bidirectional •Each offspring cell receives one copy of the DNA molecule •Replication is highly accurate due to the proofreading capability of DNA polymerase
Coagulases (enzyme)
coagulate fibrinogen
spindle (form)
colonies long and thin
Sterols
combination of cholesterol and steroid hormones; a component of plasma membranes
Use-Dilution Tests
commonly used to determine a chemical's disinfection effectiveness on an inanimate surface. •Metal cylinders are dipped in test bacteria and dried •Cylinders are placed in disinfectant for 10 min at 20 C •Cylinders are transferred to culture media to determine whether the bacteria survived treatment 1.) a cylinder of stainless steel is dipped in a culture of the targeted microorganism and then dried. 2.) The cylinder is then dipped in solutions of disinfectant at various concentrations for a specified amount of time. 3.) the cylinder is transferred to a new test tube containing fresh sterile medium that does not contain disinfectant, and this test tube is incubated. Bacterial survival is demonstrated by the presence of turbidity in the medium, whereas killing of the target organism on the cylinder by the disinfectant will produce no turbidity.
Microbial antagonism (competitive exclusion)
competition between microbes Normal microbiota protect the host by: •competing for nutrients •producing substances that are harmful to invading microbes •influencing pH and available oxygen
membrane attack complex (MAC)
complement system components assembled to form pores in membranes of invading cells LAYMAN'S TERMS Our immune system has a number of ways of killing bacteria: eating it, starving it and punching a hole in it. The MAC is a "hole-punching" machine which our immune system uses to "punch and destroy bacteria entering the blood vessels. ANALOGY A submarine is shot by a cruiser, causing a hole becomes filled with water. Submarine: pathogen water: extracellular fluids hole: ruptured pathogen membrane cruiser: MAC complex
negative strand RNA (ssRNA -)
complementary to mRNA, genome must be transcribed by viral RNA polymerase to produce viral RNA ssRNA - : (antisense) strand •The purpose of this viral RNA is to be a template to transcribed + strand RNA.
Pyruvate oxidation and the citric acid cycle
completes the breakdown of glucose in the mitochondrial matrix
Earwax (cerumen)
composed of a combination of sebum and secretions from the ceruminous; prevents microbes from entering the ear
Adenosine Triphosphate
compound used by cells to store and release energy (ATP)
effective disinfection
concentration of disinfectant organic matter pH time
Francesco Redi (1668)
conducted an experiment to explore the debate of spontaneous generation or biogenesis in which he filled jars with *decaying meat* When the jars were covered with a *fine net*, *no maggots* would infest the meat. Exposed *open* jars however resulted in *maggots*. *Sealed* jars would *not* produce maggots. BEGGING THE QUESTION Where did the maggots come? What was the purpose of the sealed jars? Spontaneous generation or biogenesis?
John Needham (1745)
conducted experiments with gravy and tainted wheat in containers in order to validate *spontaneous generation*. The experiments consisted of briefly *boiling* a broth mixture and then cooling the mixture in an open container to room temperature. Later, the flasks would be sealed, and *microbes would grow* a few days later. Those experiments *seemed* to show that there was a life force that produced spontaneous generation. Today, it is now known that the boiling time was *insufficient* to kill any endospores of microbes and the cooling of flasks left open to the air could cause microbial contamination. His experiments were later challenged and repeated by *Lazzaro Spallanzani*, an Italian scientist. Using a slightly different protocol with a longer boiling time, Spallanzani did *not* have any microbes grow in his sealed flasks, *contradicting* Needham's findings.
Hershey-Chase Experiment
confirmed that DNA, not protein, is the genetic material which determines traits by conducting an expermiment which radio-labeled the DNA and proteins of T2 Bacteriophages. These bacteriophages, which possess proteins and DNA, inject a substance into bacteria. The substance forced the bacteria to reproduce T2 bacteriophages. The substance, found in bacteriophage-infected bacteria, was identified as only radio-labeled DNA. (dummy explanation: Viral DNA can program cells. *DNA is responsible for genetic information.*)
enzyme
consists of proteins and biological catalysts (biocatalysts) •Enzymes act on a specific substrate and lower the activation energy ANATOMY •Apoenzyme: protein portion •Cofactor: nonprotein component •Coenzyme: organic cofactor •Holoenzyme: apoenzyme plus cofactor
reducing media
contain ingredients that chemically combine with O2 and are heated to kill off O2; promotes the cultivation of obligate anaerobes and anaerobic bacteria contain chemicals such as sodium thioglycolate that combine O2 to deplete it; must be heated to drive off O2
organic molecules
contain skeleton structures of carbon with hydrogen and oxygen
Diploid
containing two complete sets of chromosomes, one from each parent. •one paternal set &one maternal set •Human diploid possess 46 chromosomes
Photosystem II
contains a pair of P680 chlorophyll molecules and uses absorbed light energy to split water into protons and oxygen and to produce ATP. Transforms solar energy into chemical energy by exciting electrons and then shuttling them to different molecules/complexes -type of electron transport chain
enriched media
contains complex organic substances such as blood, serum, hemoglobin, or special growth factors required by fastidious microbes
measurements
count microbial cells through various measuring techniques Direct measurement: measuring exactly the thing that you are looking to measure indirect measurement: measuring something by measuring something else; using inferences TECHNIQUES •Plate count •Filtration •Direct microscopic count
capsule
covers the cell wall in prokaryotes (bacteria) * can be a mechanism for the bacteria penetrate host defenses • impairs the host cell's phagocytosis of the bacteria
sarcinae cocci
cube shaped cocci stuck together on 3 planes of divisoin
Starch Agar
cultivating organisms being tested for starch hydrolysis
interferons
cytokines (type of protein) secreted by T cells and other cells to aid and regulate the immune response
Ribosome
cytoplasmic organelles from which proteins are synthesized
mortality
death; death rate
Degermination
degerming; the mechanical removal of microbes from a limited area I.e. handwashing
Desiccation
dehydration; the process of being rendered free from moisture
high pressure
denatures proteins
cell-mediated
denoting the aspect of an immune response involving the action of white blood cells, rather than that of circulating antibodies. (T cells)
Differential media
designed to make it easier to distinguish colonies of different microbes •Some media have both selective and differential characteristics
IgA protease
destroy IgA antibodies
Disinfection
destroying harmful microorganisms; a process that eliminates many microorganisms, with the exception of bacteria spores, from inanimate objects
cytotoxic
destructive to cells
EMB
detection and isolation of gram negative bacteria
Peptone
detects absence of hydrogen sulfide positive=pH strip is black negative=pH strip is white (no H2S)
Nitrate Reduction
determine if bacteria reduces nitrates (NO3) to nitrites (NO2) positive=bubbles in tube after adding solution negative=no bubbles in tubes
Nitrate Broth
determine nitrate reduction in bacteria
Glucose Broth Lactose Broth Sucrose Broth
determines if bacteria ferment carbohydrates and produce gas yellow=acid made and when sugar fermented blue color=base made because proteins are broken down-oxidizes peptones and ammonia is produced green= no acid produced (no fermentation) and no gas production air space->gas produced in a vial 1/2 air filled=4+ 1/3 air filled=3+ 1/4 air filled=2+ barely=1+
Catalase Activity
determines if bacteria has the enzyme catalase by adding H202 to nutrient agar positive=foaming negative=no foaming
Biochemical Tests
determines presence of bacterial enzymes • Rapid identification methods are able to perform several biochemical tests simultaneously • Results of each test are assigned a number
hematopoiesis (hemopoiesis)
development of blood cells to their mature form
pathogenesis
development of disease
Ig M (Immunoglobulin M)
develops in blood plasma as a response to bacteria or antigens in food.
phylogenetic tree (cladogram)
diagram tracing evolutionary relationships between species •Grouping organisms according to common properties: -Fossils -Genomes •Groups of organisms evolved from a common ancestor •Each species retains some characteristics of its ancestor
phase
differentiate between transparent protoplasmic structures and enhance contrast between the cell and surroundings without staining
serial dilution
dilution of a substance several times by the same amount each time
Clostridium difficile (C. diff)
disease caused by the disruption of normal healthy bacteria in the colon, often from antibiotics can also be transmitted from person to person by spores. It can cause severe damage to the colon and even be fatal. Symptoms include diarrhea, belly pain, and fever. Treatment includes antibiotics. Even when treated with antibiotics, the infection may come back. In rare cases, fecal transplant or surgery may be needed.
Notifiable infectious diseases
diseases in which physicians are required to report occurrence
cell plate
divides a cell into two and is a precursor of a new plant cell wall that forms during cell division. a) Membrane-enclosed vesicles collect along middle. b) vesicles fuse, forming cell plate c) The cell plate eventually becomes a new cell wall.
Cytokenesis
division of the cytoplasm to form separate daughter cells
areotolerant anaerobes
do not utilize oxygen but can survive and grow to a limited extent in its presence
Watson-Crick DNA model
double helix (twisted ladder) *MODEL* phosphate-sugar-nitrogenous base-hydrogen bond-nitrogenous base-sugar-phosphate NOTE: Hydrogen bonds are weak. This helps the DNA be rearranged easier during replication.
Nucleus
double membrane structure (nuclear envelope) that contains the cell's DNA •DNA is complexed with histone proteins to form chromatin •During mitosis and meiosis, chromatin condenses into chromosomes -"Control center of the cell" -contains genes/DNA
chemotherapy
drug treatment that uses powerful chemicals to kill fast-growing cells in your body; most often used to treat cancer, since cancer cells grow and multiply much more quickly than most cells in the body a predisposing factor that can make the body more susceptible to disease
antiviral drugs
drugs that inhibit the growth of viruses by inhibiting the entry or fusion of the virus with the target cell's membrane FUNCTION • block the receptors on the host cell that bind to the virus • block fusion of the virus and cell TYPES OF INHIBITORS Inhibitors of • the uncoating process • genome integration • nucleic acid synthesis • viral uncoating • viral DNA integration into the host genome Nucleoside analogs can be used to inhibit RNA or DNA synthesis.
dissication
drying out
dissication
drying out; absence of water prevents metabolism
plaque-forming units (PFU)
each plaque corresponds to a single virus; concentrations of viral suspensions measured by the number of plaques
Prodromal
early symptoms that may indicate the onset of a condition or disease
phage
eat, swallow
oocyte
egg cell
NAD+
electron carrier involved in glycolysis Nicotinamide adenine dinucleotide •Assist enzymes; electron carrier
oxidative phosphorylation
electron transport chain and chemiosmosis Oxidative: electrons are lost from each complex (oxidized) and passed along until they are added to oxygen to form water Phosphorylation: energy produced by transfer of electrons is used to add a phosphate group onto ADP As electrons trickle "downhill" through the transport chain, they release energy, and some of this energy is captured in the form of an electrochemical gradient and used to make ATP.
compliment system (complement cascade)
enhances the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promote inflammation, and attack the pathogen's cell membrane. It is part of the innate immune system. The complement system can, however, be recruited and brought into action by antibodies generated by the adaptive immune system. Group of about 30 proteins in blood plasma that complement defense reactions and help attract phagocytes to foreign cells; can help promote lysis of the foreign cell FUNCTION • Serum proteins produced by the liver that assist the immune system in destroying microbes • complement activation • Proteins are designated with uppercase "C" and numbered in order of discovery •Activated fragments are indicated with lowercase "a" and "b"
Blood Agar
enrinched and differential media used for isolation and cultivating fastidious microorganisms
direct microscopic count
enumeration of cells by observation through a microscope 1.) Volume of a bacterial suspension placed on a slide 2.) Average number of bacteria per viewing field is calculated •Uses a special Petroff-Hausser cell counter FORMULA (Number of bacteria)/(ml) = (Number of cells counted)/(Volume of area counted)
NADP+ reductase
enzyme that transfers a proton and two electrons from ferredoxin to NADP+, forming NADPH (2 ELECTRONS are required).
Proteases
enzymes that break down proteins
Melanocytes
epidermal cell that produces melanin
Langerhans cells
epidermal macrophages that help activate the immune system by antigen-presenting, a process in which they process antigens and present them to T-cells.
flat (elevation)
even with agar
Adhesins (ligands)
external component of most pathogens that are designed to bind to complementary receptors on host cells; the ligands are a type of molecule (Think about the chemistry definition of a ligand) when enough pathogens bind to the host, biofilms can be formed •Glycocalyx •Fimbriae
Psychrophile
extremophilic organisms that are capable of growth and reproduction in low temperatures −20 °C to 10 °C occupy environments that are permanently cold, such as the polar regions and the deep sea. Contrast this with thermophiles, which are organisms that thrive at unusually high temperatures. Greek for 'cold-loving' Most are bacteria or archaea EXCEPTION Some eukaryotes, such as lichens, snow algae, fungi, and wingless midges
immunodeficiency
failure of the immune system to protect the body adequately from infection due to the absence or insufficiency of some component process or substance • Congenital immunodeficiencies: due to defective or missing genes • Acquired immunodeficiencies: develop during an individual's life due to drugs, cancers, and infections
Ovaduct
fallopian tubes; where fertilization takes place
filamentous (form)
fibrous with stringy extensions
lymph nodes
filters ("bean-shaped") that cluster along the lymphatic vessels of the body; They function to clean the lymph and are a site where T and B cells are activated GENERAL PROCESS 1.) Dendritic cells consume pathogens. Although they can kill pathogens, their main purpose is to present the pathogen to the T or B cells. 2.) They bring fragments of the pathogen to a lymph node. The lymph node is like a party; many different kinds of inactive T and B cells reside here. The inactive T and B cells are blind, they can't activate until a dendritic cell brings them a sample of the pathogen. 3.) Some of the T and B cells in the node bind to the fragments of the pathogen via receptor sites. T and B cells have many variations because there are many types of receptors. The only T/B cells that bind to the pathogen fragments are the ones that have the corresponding receptors to the pathogen. • The inactive B cells possess surface immunoglobins (Ig) that binds to the antigen. • The B cell internalizes and processes the antigen. •Antigen fragments are displayed on MHC class II molecules 4.) The B and T cells that binded to the pathogen are activated; causing them to proliferate (quickly reproduce so that there are enough of them to fight the infection). • T helper cell (TH) contacts the displayed antigen fragment and releases cytokines that activate B cells. • B cell undergoes proliferation (clonal expansion) 5.) The resulting proliferated cells can become memory cells or effector cells, or antibody-producing plasma cells •Antibody-producing plasma cells
Telophase
final phase of mitosis in which the distinct individual chromosomes begin to spread out into a tangle of chromatin. -nuclei reappear -spindle disappears (When telophase ends, cytokinesis has begun)
FAD
flavin adenine dinucleotide; an energy carrier that accepts electrons and delivers them to the electron transport chain •Assist enzymes; electron carrier
Vertical gene transfer
flow of genetic information from one generation to the next
horizontal gene transfer
flow of genetic information within the same generation The transfer of genes from one genome to another through mechanisms such as transposable elements, plasmid exchange, viral activity, and sometimes fusions of different organisms.
Stroma
fluid portion of the chloroplast; outside of the thylakoids
nutrient agar
food source for microorganisms (exams water and dairy products)
Antigens
foreign substances that trigger the attack of antibodies in the immune response •They usually appear as components of invading microbes or foreign substances. •Antibodies interact with epitopes, (antigenic determinants) on the antigen •Haptens: antigens too small to provoke immune responses; they must attach to carrier molecules
Lyophilization
freeze drying; preservation
Lyophilization (freeze-drying)
frozen, -54 C to -72C, and dehydrated in a vacuum; method of preserving bacterial cultures
Merkel cells
function as touch receptors in association with sensory nerve endings
Hematopoietic cytokines
function in controlling the pathways by which stem cells develop into different red or white blood cells
parenchyma
functional tissues of any organ (such as the tissues of the bronchioles, alveoli, ducts, and sacs, that perform respiration)
reduction
gain of electrons
Oxygen
gas that enters the blood through the lungs and travels to the heart to be pumped via arteries to all body cells CLASSIFICATION Obligate aerobes require oxygen. Facultative anaerobes grow via fermentation or anaerobic respiration (no oxygen) Obligate anaerobes are unable to use oxygen and are harmed by it Aerotolerant anaerobes tolerate but don't use oxygen Microaerophiles require oxygen concentration lower than air Microaerophiles require oxygen concentration lower than air COMPOUNDS Superoxide radicals: O2^-1 Peroxide anion: O2^2- Hydroxyl radical: OH; notice that this is the neutral form of (OH-)
point mutation
gene mutation in which a single base pair in DNA has been changed changes in a single nucleotide
repressible operons
genes are expressed (on), meaning that transcription takes; but these genes can be repressed (off) when certain molecules, repressors, bind to the operon •Excess tryptophan is a corepressor, meaning it binds to and activates the repressor that, in turn, binds to the operator, stopping tryptophan synthesis
selectable marker gene
genes carried by plasmids for certain traits, often for antibiotic resistance •Positive (direct) selection: beneficial traits; detects mutant cells because they grow or appear different than unmutated cells •Negative (indirect) selection: detrimental traits; detects mutant cells that cannot grow or perform a certain function
Conjugative Plasmid (F Factor)
genes for production of sex pili and transfer of the plasmid
resistance genes
genes often in plasmids or transposons that can be transferred between bacteria that enable resistance to antibiotics • often spread horizontally (among bacteria of the same generation, rather than inherited to an offspring) via plasmids or transposons through conjugation or transduction
inhereted traits
genes passed from parent to offspring; a predisposing factor that can make the body more susceptible to disease
Consecutive genes
genes that are expressed at a fixed rate
Oncogenes
genes that cause cancer by blocking the normal controls on cell reproduction; can come from oncogenic viruses •Oncogenic viruses become integrated into the host cell's DNA and induce tumors (Adenoviridae, Epstein-Barr virus, Human papillomavirus, Hepatitis B virus)
genotype
genetic makeup of an organism; determines the phenotype of an organism
Sucrose
glucose + fructose *produced by leaf cells *transported throughout the plant via vascular bundles
lipids
glycerol + fatty acids Glycerol converted to glyceraldehyde 3-phosphate (produced during glycolysis) Breaking down fatty acid chains into 2 carbon fragments (acetyl groups)
natural killer cells (NK cells)
granular leukocytes that kill cells infected by viruses or cancer and human cells that don't possess MHC class I • They also attack parasites. • They don't have to be stimulated by an antigen to function (which is in constrast to Cytotoxic T cells). • They create pores in the target cell, causing lysis via apoptosis (Human cells must express MHC class I molecules because they signal to NK cells that they are a part of the human body. NK cells attack cells that don't possess MHC class I molecules.)
Inclusion bodies (granules)
granules of storage material such as sulfur that accumulate within some bacterial cells
Staphylococci
grape-like clusters of cocci stuctures
tetrad cocci
group of four spheres with 2 planes of division
Anticodon
group of three bases on a tRNA molecule that are complementary to an mRNA codon
general purpose media
grows a broad range of microbes, usually nonsynthetic
selective media
has agents that suppress growth of unwanted bacteria and encourage growth of desired microbes
entire (margin)
have smooth edges
Edward Jenner (1796)
he *inoculated* (vaccinated) a person afflicted with the cowpox virus, who was then immune from smallpox •Vaccination is derived from the Latin word "vacca" meaning cow •The protection is called *immunity*.
Thermoduric
heat resistant
Elevation
height of colony compared to the surface of agar
Virus Morphology
helical hollow, cylindrical rod-shaped capsid polyhedral many sides; hollow polygon; almost a sphere enveloped •Envelope consists of lipids, proteins, and carbohydrates; a coating of some viruses complex Complex viruses-such as bacteriophages-possess a capsid which is neither purely helical, nor purely icosahedral, and which may have extra structures such as protein tails or a complex outer wall.
Pathogen-associated molecular patterns (PAMPs)
help the innate immune system recognize pathogens molecules recognized by toll-like receptors (TLRs) and other pattern recognition receptors (PRRs) in both plants and animals. activate innate immune responses, protecting the host from infection, by identifying some conserved nonself molecules. The recognition of PAMPs usually triggers the activation of several signaling cascades in the host immune cells like the stimulation of interferons (IFNs) or other cytokines. EXAMPLE Bacterial lipopolysaccharides (LPSs), endotoxins found on the cell membranes of gram-negative bacteria are considered to be the prototypical class of PAMPs. LPSs are specifically recognised by TLR4, a recognition receptor of the innate immune system. Other PAMPs include bacterial flagellin (recognized by TLR5), lipoteichoic acid from gram-positive bacteria (recognized by TLR2), peptidoglycan (recognized by TLR2),[3] and nucleic acid variants normally associated with viruses, such as double-stranded RNA (dsRNA), recognized by TLR3 or unmethylated CpG motifs, recognized by TLR9.
Fungi
heterotrophs: They acquire their food by absorbing dissolved organic molecules, typically by secreting digestive enzymes into their environment. -do not photosynthesize. -possess chitin in their cell walls -one of the six kingdoms •Eukaryotic •Distinct nucleus Growth is their means of mobility, except for spores, which may travel through the air or water. the principal decomposers in ecological systems. YEASTS, MOLD, AND MUSHROOMS •Yeasts are unicellular •Molds and mushrooms are multicellular •Molds consist of masses of mycelia, which are composed of filaments called hyphae.
HEPA filter
high-efficiency particulate air filter; removes microbes that are greater in size than 0.3 μm
mechanical stage
holds the slide in position for viewing
Prophase I (Meiosis)
homologous chromosomes pair up and form tetrads, crossing over occurs
Anaphase I (Meiosis)
homologous chromosomes separate (YEET!) (Mendel's observation of the segregation of alleles in gamete formation has its basis in this division.) Half the genome heads toward one centriole and other half heads toward the other.
compromised host
host with lowered resistance to infection and disease These impairment(s) come most eminently from diseases, therapy, or burns but also from predisposing factors: •Gender •Inherited traits (such as the sickle cell gene) •Climate and weather •Fatigue •Age •Lifestyle •Nutrition •Chemotherapy
pH
hydrogen ion concentration; scale that conveys how acidic or basic something is •Most bacteria grow between pH 6.5 and 7.5 •Molds and yeasts grow between pH 5 and 6 •Acidophiles grow in acidic environments
Hyaluronidase
hydrolyzes hyaluronic acid (a polysaccharide responsible for holding together connective tissue) thus promoting the spread of pathogen; produced by streptococci
atopy
hypersensitive or allergic state involving an inherited predisposition
Cytotoxic (Type II) Hypersensitivity
hypersensitivity elicited when the immune system recognizes antigens on human cells as foreign • this is why blood transfusions requires different blood-types ABO Blood Group System Antibodies form against certain carbohydrate antigens found on RBCs (red blood cells) • A antigens, B antigens, or both • Type O RBCs don't possess any antigens Activation of complement by the combination of IgG or IgM antibodies with an antigenic cell; causes cell lysis or damage by macrophages
transplant rejection
identification of transplanted tissue as foreign by the recipient's immune system, which responds by attacking the tissue
transplant rejection
identification of transplanted tissue as foreign by the recipient's immune system, which responds by attacking the tissue Transplants may be attacked by T cells, macrophages, and complement-fixing antibodies. Transplants involving the transplant of privileged tissue to a privileged site does not cause an immune response. • Cornea transplants are reliable because antibodies don't circulate into that portion of the eye. •Heart valve transplants can involve replacing a person's damaged heart valve with a valve from a pig's heart.
oxidase test
identifies bacteria that have cytochrome oxidase It uses disks containing a reagent and redox indicator. The reagent is a dark-blue to maroon color when oxidized, and colorless when reduced. Oxidase-positive bacteria possess cytochrome oxidase or indophenol oxidase (an iron-containing hemoprotein). These both catalyze the transport of electrons from donor compounds (NADH) to electron acceptors (usually oxygen). The test reagent, TMPD dihydrochloride acts as an artificial electron donor for the enzyme oxidase. The oxidized reagent forms the colored compound indophenol blue. The cytochrome system is usually only present in aerobic organisms that are capable of using oxygen as the terminal electron acceptor. The end-product of this metabolism is either water or hydrogen peroxide (broken down by catalase).
Peptone agar
identifies hydrogen sulfide production in microorganisms
Parfocal
image stays in focus from low power objective to high power objective
cell lines
immortalized cells that continue to grow and divide indefinitely in vitro for as long as the correct culture conditions are maintained
inate immunity
immunity that exists in a person without prior contact with an antigen; these nonspecific defense mechanisms activate immediately or quickly once an antigen appears. These mechanisms include physical barriers such as skin, chemicals in the blood, and immune system cells that attack foreign cells in the body. (inate: "born with; natural.") This is the kind of immunity a person is born with.
IgM
immunoglobulin M; initial response antibodies A compliment complex can be activated by the combination of IgG or IgM antibodies with an antigenic cell • Causes cell lysis or damage by macrophages • Transfusion reactions If this is the first time the antigen has been encountered, a primary immune response is mounted. Usually there is a delay of several days, then IgM antibody is produced, followed by a switch to IgG antibody production. The initial IgM molecules bind the antigen weakly, but the subsequent IgG molecules are much better targeted. IgG continues to be produced long after the encounter with the antigen, providing long-lasting immunity.
gender
in a biological sense, male or female; the rarely hot but mainly appallingly hideous blue-haired lesbians would beg to differ a predisposing factor that can make the body more susceptible to disease
vitro
in glass, in a test tube
conserved
in the context of evolution, referring to a trait that is passed on from a common ancestor to two or more descendant species
Toxoid
inactivated exotoxin used in a vaccine
toxoid
inactivated toxin used in a vaccine
Fomite
inanimate (lacking life or motion) object that can potentially harbor a pathogen (Fomites don't necessarily have to encourage the pathogen's growth or sustainability.) Compare this definition to a reservoir of infection
sepsis
infection; bacterial contamination
Opa protein
inhibits T helper cells; allows attachment to host cells
Bacterialstatic
inhibits bacterial or microbial growth
catabolite repression
inhibits cells from using carbon sources other than glucose
Repression
inhibits gene expression and decreases enzyme synthesis •Mediated by repressors, which are proteins that block transcription •Default position of a repressible gene is on
low temperature
inhibits microbial growth •bacteriostatic effect METHODS •Refrigeration •Deep-freezing •Lyophilization (freeze drying)
static agents
inhibits or control the growth of microbes without killing them static: fixed, not moving or changing, lacking vitality
Diptheria (toxin)
inhibits protein synthesis and ultimately leads to cell death
Phenol and Phenolics
injures lipids of plasma membranes, causing leakage - Denature proteins and disrupt cell membranes - Effective in the presence of organic matter - Remains active for prolonged time - Commonly used in health care settings, labs, and homes - distinguishing odors and possible side effects
Interferons (IFNs)
interfere with viral infections of host cells *cytokines are produced that have antiviral activity
Peristalsis
involuntary waves of muscle contraction that keep food moving along in one direction through the digestive system
Hemoglobin
iron-containing protein in red blood cells that carries oxygen for delivery to cells; reversibly binds oxygen
Curved bacilli
irregular shaped bacillus
Mantinol Salt
isolation of pathogenic staphylococci
Phenyethanol Agar
isolation of staphylococci and streptococci from gram negative species
Vaccine types
killed / inactivated • viruses are inactivated • bacteria are killed • require repeated booster doses • Induce mostly humoral immunity Live, attenuated • weakened pathogen • Closely mimic an actual infection • often results in life-long cellular and humoral immunity Antigenic molecules Genetically engineered microbes or antigens. Conjugated vaccines • Used for diseases in those (usually children) with poor immune response to capsular polysaccharides (polysaccharides combined with diphtheria or tetanus toxoid) • The successful vaccine for Haemophilus incluenzae type b)
Bactericidal
kills bacteria or microbes
mechanical stage controls
knobs used to move the mechanical stage left and right or up and down
suceptibility
lack of resistance to a disease
Peyer's patches
large collections of lymphoid tissue found in the submucosa of the small intestine
macrophage
large phagocyte found in lymph nodes and other tissues of the body •"phago-": eat; "-cyte": cell •Fixed macrophages: macrophages confined to tissues and organs •Free (wandering) macrophages: macrophages that wander to various tissues and gather at sites of infection
skin
largest organ of the body; provides inate immunity EPIDERMIS: outer layer, connected to the dermis via connective tissue contains Merkel cells, keratinocytes, melanocytes, Langerhans cells DERMIS: middle layer; epithelial cells, keratin, connective tissue HYPODERMIS: inner layer; fat, sweat glands, root of hair follicle, blood vessels, connective tissue The shedding and dryness of the skin inhibit microbial growth.
T cells
leukocytes (white blood cells) created in the thymus that produce substances that attack infected cells in the body • Thymic selection eliminates immature T cells • They migrate from the thymus to lymphoid tissues • They have T-cell receptors (TCRs) which allow them to attach to antigens
corticosteroids (steroids)
lipid molecules with four fused carbon rings that function to decrease inflammation and reduce the activity of the immune system.
nutrient broth
liquid complex medium
nutrient broth
liquid medium containing beef extract and peptone; take sample directly from tube
Approved Lists of Bacterial Names
lists species of known prokaryotes; based on published articles (lists species of known classification) Contrast this with Bergey's Manual of Determinative Bacteriology, which provides identification schemes for identifying bacteria and archaea
Probiotics
live microbes applied to or ingested into the body, intended to exert a beneficial effect
Localized anaphylaxis
localized: confined area anaphylaxis: a severe response to an allergen in which the symptoms develop quickly • Usually associated with ingested or inhaled antigens • Symptoms depend on the route of entry (Hives, hay fever, and asthma)
filamentous (margin)
long indentations
sex pili
longer than fimbriae and allow prokaryotes to exchange DNA
euchromatin
loosely packaged, or coiled DNA and proteins -the most active transcriptions occurs here since RNA polymerase can access the DNA and proteins easier present any time before prophase and after telophase DNA is easily accessible to DNA replication
lysis
loosening, destruction
oxidation
loss of electrons
natural killer cells (NK cells)
lymphocyte that function in cell-mediated, cytotoxic innate immunity; they pursue diseased cells such as those infected by viruses or cancer
T cells
lymphocyte that identifies pathogens and distinguishes one pathogen from another; for cell-mediated, cytotoxic adaptive immunity
B cells
lymphocyte that produces antibodies
centrifuge
machine that separates substances by whirling them. Centrifugal force makes the heavier substances gravitate towards one end of a test tube, and lighter substances towards the other end.
pollen grain
male gametophyte in seed plants The microspore mother cell divides by meiosis to give rise to four microspores •Each microspore will ultimately form a pollen grain •Mature pollen grains contain two cells: a *generative cell* and a *pollen tube cell*. •The generative cell is contained within the larger pollen tube cell. •the tube cell forms the pollen tube through which the generative cell migrates to enter the ovary. •During its transit inside the pollen tube, the generative cell divides to form two mature male gametes. •Upon maturity, the *microsporangia* burst, releasing the pollen grains from the anther.
MMR vaccine
measles, mumps, rubella
titer
measure of the number of infectious units or antibodies per volume of fluid ANTIBODY (Immunoglobulin, Ig) the relative amount of antibody in a serum reflects intensity of the humoral (antibody-based) response • PATTERN: IgM is produced first, followed by IgG
Turbidity
measurement of "cloudiness" with a spectrophotometer •Metabolic activity: amount of metabolic product is proportional to the number of bacteria •Dry weight: bacteria are filtered, dried, and weighed; used for filamentous organisms
Sensitivity
measurement of the proportion of actual "positive" test results that are correctly identified (e.g., the percentage of sick people who are correctly identified as having the condition)
MALDI-TOF
measures the masses of various components using mass spectrophotometer ACRONYM Matrix Assisted Laser Desorption/Ionization-Time of Flight
specificity
measures the proportion of actual negatives in a test that are correctly identified (e.g., the percentage of healthy people who are correctly identified as not having the condition).
Glycolipids
membrane carbohydrates that are covalently bonded to lipids
Glycoproteins
membrane carbohydrates that are covalently bonded to proteins
mucous membrane (mucosa)
membranes that form the linings of body cavities that open to the exterior (such as digestive, respiratory, urinary, and reproductive tracts) •Epithelial layer that lines the gastrointestinal, respiratory and genitourinary tracts •Mucus: viscous glycoproteins that trap microbes and prevent tracts from drying out
amphibolic pathways
metabolic pathways that have both catabolic and anabolic functions •Many pathways function simultaneously with common intermediates
conservative replication
method of DNA replication in which the parental molecule serves as a template for the synthesis of an identical copied molecule
Gas-pak
method used in the production of an anaerobic environment. It is used to culture bacteria which die or fail to grow in the presence of oxygen (anaerobes). •CO2 packet These are commercially available, disposable sachets containing a dry powder or pellets, which, when mixed with water and kept in an appropriately sized airtight jar, produce an atmosphere free of elemental oxygen gas (O2). They are used to produce an anaerobic culture in microbiology. It is a much simpler technique than the McIntosh and Filde's anaerobic jar where one needs to pump gases in and out.
plaque assay
method used to measure the number of viral particles present in a sample
animal virus controlled growth
methods of growing animal viruses in a laboratory: 1) In living animals 2)In embryonated eggs •The virus is injected into the egg. •Changes or death of the embryo indicate viral growth. 3) In cell cultures •Tissues are treated with enzymes to separate cells •Virally infected cells are detected via their deterioration, known as the cytopathic effect (CPE) •Continuous cell lines are used The terms embryonated, unembryonated and de-embryonated respectively mean "having an embryo", "not having an embryo", and "having lost an embryo", and they most often refer to eggs.
Inoculum
microbes that are introduced into a culture medium to initiate growth
microbiota
microbes which are normally present in and covering the human body; usually beneficial •Transient microbiota are temporary and may be present for days, weeks, or months. •Normal microbiota permanently colonizes the host and don't cause disease under normal conditions. •Human Microbiome Project analyzes relationships between microbial communities on the body and human health
waxy
microbes with a waxy covering are hard to stain; they are resistant to dissication and disinfectants heat can be used to penetrate the waxy cell wall
persister cells
microbes with genetic characteristics that enable them to survive when exposed to an antibiotic
obligatory intracellular parasites
microparasites that are capable of growing and reproducing inside the cells of a living host; some parasites can cause disease. •Contain DNA or RNA •Contain a protein coat •No ribosomes •No ATP-generating mechanism
electron microscope (EM)
microscope that forms an image by focusing beams of electrons onto a specimen TYPES: *scanning* and *transmission* Invented in 1940-1950 •able to magnify cells *thousands* of times stronger than light microscopes (maximum magnification is *1000x*) •cells could be observed like never before; allowed studies to show *structural* differences
oil immersion
mineral oil placed between lens and slide and allows for all the light to be directed into objective
M phase
mitosis and cytokinesis
ceruminous glands
modified sweat glands, located in external ear canal, secretes cerumen (earwax)
Polymer
molecules composed of many monomers; makes up macromolecules
metabolites
molecules that are chemical products of metabolism
base analogues
molecules that have a very similar structure to one of the four nitrogenous bases which are used in DNA (adenine, guanine, cytosine or thymine). They form a structure similar to one of the DNA nucleotides and then can be used to form the new strand in semi-conservative replication. 1 The body mistakes them as the nitrogenous base type that belongs in the double helix and incorporates it instead. 2 Once in the DNA helix, some base analogs change shape. 3 This means that if they're used as a template strand during replication, they will pair with a different base and cause a base change mutation.
Nucleotide
monomer of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group. INHERITANCE The four bases found in DNA are *adenine (A), cytosine (C), guanine (G), and thymine (T)*. These four bases are attached to the sugar-phosphate to form the complete nucleotide.
amino acids
monomers of proteins INHERITANCE There are over 500 types of amino acids found in nature, yet *the human genetic code only directly codes for 20 types*. Every protein in your body is made up of some linked combination of these amino acids: alanine arginine asparagine aspartic acid cysteine glutamine glutamic acid glycine histidine isoleucine leucine lysine methionine phenylalanine proline serine threonine tryptophan tyrosine valine
dynein
motor protein that drives the bending movements of a cilium or flagellum.
vaginal secretions
move microorganisms out of the vaginal tract •its low pH [ 3-5 ] inhibit microbial growth
simple diffusion
movement of a solute from an area of high concentration to an area of low concentration; a type of passive transport •Continues until molecules reach equilibrium
Transcytosis
moving substances into, through, and then out of a cell; a combination of endocytosis and exocytosis
ulcerative colitis (UC)
mucosal disease characterized by inflammation of the colon with the formation of ulcers, which can cause bloody diarrhea
compound
multiple lens system
Resistance mutants
mutants that can grow on media containing an antibiotic • the misuse of antibiotics selected for resistance mutants
Frameshift mutation
mutation that involves the insertion of a new base or the removal of a pre-existing base in the DNA sequence; •Shifts the translational "reading frame" When this happens, the codon-which consists of three bases in a sequence-is disrupted in such a way that the tRNA will bring the wrong amino acids since the pattern is out of order. EXAMPLE Consider this hypothetical strand. CAT CAT CAT CAT... The CAT codon signals for the tRNA that has its corresponding anticodon (GUA). This type of tRNA will bring the histidine amino acid. Say a mutation occurs in which an adenine is introduced. CAT CAT A CAT CAT... The codons are now arranged like this: CAT CAT ACA TCA TCA .... After the adenine is added, the codons are rearranged. The codon ACA corresponds to a tRNA with a different anticodon, which will bring the wrong amino acid. The proceeding codons, which correspond to TCA, will also correspond to a type of tRNA with a different anticodon that will bring the wrong type of amino acid.
selectable mutations
mutations that give the mutant a growth advantage under certain conditions; useful in genetic research •Positive (direct) selection: beneficial traits; detects mutant cells because they grow or appear different than unmutated cells •Negative (indirect) selection: detrimental traits; detects mutant cells that cannot grow or perform a certain function
spontaneous mutations
mutations that occur in the absence of a mutagen •Spontaneous mutation rate 1: 10^9 replicated base pairs are mutated on average 1: 10^6 replicated genes are mutated on average •Mutagens increase the mutation rate to 10^-5 or 10^-3 per replicated gene
extracellular polymeric substance (EPS)
natural polymers of high molecular weight secreted by microorganisms into their environment. EPSs establish the functional and structural integrity of biofilms, and are considered the fundamental component that determines the physiochemical properties of a biofilm. a glycocalyx that helps cells in a biofilm attach to their target environment and to each other
inorganic molecules
non-carbon based molecules
Chocolate Agar
nonselective blood medium used for fasstidious microorganisms
Anton van Leeuwenhoek (1623-1673)
observed the first microbes, calling them "Animalcules" viewed through magnifying lenses (300X)
persistent viral infection
occurs gradually over a long period; is generally fatal •Subacute sclerosing panencephalitis (measles virus)
Blebbing
occurs when a cell cuts its genome into fragments, causing the detachment of its cytoskeleton from the membrane. This in turn causes the membrane to swell into spherical bubbles, greatly distorting the shape of the cell • Most commonly, blebs (cells which have undergone blebbing) are a result of apoptosis (programmed cell death)
Systemic anaphylaxis (anaphylactic shock)
occurs when an individual sensitized to an antigen is exposed to it again; an extreme, often life-threatening allergic reaction to an antigen to which the body has become hypersensitive • may result in circulatory collapse and death • treated with epinephrine, must be soon • this reaction can occur within seconds or minutes of exposure to an allergen Symptoms include rash, nausea, vomiting, difficulty breathing, shock
superinfection
occurs when an overgrowth of normal microbiota causes them to be resistant to antibiotics
drug synergism
occurs when multiple drugs interact together to become more effective than if each drug was independent of the other EXAMPLE The combination of trimethoprim and sulfamethoxazole (TMP-SMZ) • only 10 % of the combined concentration is necessary
antagonism
occurs when the effect of two drugs together is less than the effect of either drug alone • CONTRAST with synergism: the effect of two drugs together is greater than the effect of either alone
sebum (oil)
oily substance that gives protection from external factors such as invasion by certain bacteria pH a protective film that lowers the pH of the skin to around 3 to 5. The average pH of the skin is about 5.5
monocular
one ocular
Cyclin
one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells G₁/S cyclins •Get cell through start binds cdks at the end of G1, commit cell to DNA replication (cyclin E) S cyclins bind cdks during S phase, required to initiate replication (cyclin A) •Stimulate DNA replication M cyclins bind cdks immediately before M phase, initiate early mitotic (or meiotic) events (cyclin B) •Stimulate mitosis by activating CdKs in late G₂ G₁ cyclins involved in progression through the checkpoint in late G1 (cyclin D) •Help control the G₁ /S cyclins
Chromatid
one of two identical "sister" parts of a duplicated chromosomes; Replicated DNA and various proteins, especially histone proteins.
Prokaryotic DNA replication
only ONE origin of replication; DNA is synthesized in both directions until the entire chromosome is copied
secondary infection
opportunistic infection can present itself after a primary (predisposing) infection
coenzyme
organic cofactor
vitamin
organic molecule that helps regulate body processes; essential nutrients that do not yield energy, but that are required for growth and proper functioning of the body
Microorganisms (microbes)
organism(s) that are too small to be seen with the naked eye TRAITS: • Can be pathogenic (disease-producing) •Decompose organic waste •Generate oxygen by photosynthesis •Produce chemical products such as ethanol, acetone, and vitamins •Produce fermented foods (such as vinegar, cheese, and bread) •Produce products used in manufacturing (such as cellulase) and disease treatment (such as insulin) and antibiotics (such as penicillin) Types of Microorganisms: •Bacteria •Archaea •Fungi •Protozoa •Algae •Viruses •Multicellular Animal Parasites
Chemoheterotrophs
organisms that must consume organic molecules for both energy and carbon are unable to synthesize their own organic molecules. Instead, these organisms must ingest preformed carbon molecules, such as carbohydrates and lipids, synthesized by other organisms. They do, however, still obtain energy from the oxidation of inorganic molecules like the chemoautotrophs. are only able to thrive in environments that are capable of sustaining other forms of life due to their dependence on these organisms for carbon sources. are the most abundant type of chemotrophic organisms and include most bacteria, fungi and protozoa.
Helminths
parasitic worms
Mitosis
part of eukaryotic cell division during which the cell nucleus divides -occurs with somatic cells -results in 2 cells identical to each other & the original cell -For normal cell function (growth, repair, replacement) and asexual reproduction
Mitosis
part of eukaryotic cell division during which the cell nucleus divides i) Prophase ii) Metaphase iii) Anaphase iv) Telophase
flaming
pass items through a flame inoculates loops and straight-wires in microbiology labs for streaking. Leaving the loop in the flame of a Bunsen burner or alcohol burner until it glows red ensures that any infectious agent is inactivated. This is commonly used for small metal or glass objects, but not for large objects (see Incineration below). However, during the initial heating, infectious material may be sprayed from the wire surface before it is killed, contaminating nearby surfaces and objects. Therefore, special heaters have been developed that surround the inoculating loop with a heated cage, ensuring that such sprayed material does not further contaminate the area. Another problem is that gas flames may leave carbon or other residues on the object if the object is not heated enough. A variation on flaming is to dip the object in a 70% or more concentrated solution of ethanol, then briefly touch the object to a Bunsen burner flame. The ethanol will ignite and burn off rapidly, leaving less residue than a gas flame.
antibiograms
periodic reports that record the susceptibility of organisms encountered (in a clinical setting) to antibiotics
normal microbiota
permanently colonize the host and don't cause disease under normal conditions •Some normal microbiota are opportunistic pathogens The distribution and composition of normal microbiota are determined by: •Nutrients •Physical and chemical factors •Host defenses •Mechanical factors (such as the flushing of urine, which removes unattached microbes)
metabolic cooperation
phenomenon that one species lives off the products of another species. In this association, the growth of one partner is improved, or depends on the nutrients, growth factors or substrate provided by the other partner cooperation between prokaryotes allows them to use resources they could not use individually
microbial control agents
physical or chemical agents; designed to inhibit or prevent growth of microorganisms by either killing them or inhibiting their growth. •Alteration of membrane permeability •Damage to proteins (enzymes) •Damage to nucleic acids Cidal agents: agents that kill cells Static agents: inhibits the growth without killing them. - bactericidal: the killing of bacteria - bacteriostatic: inhibiting the growth of bacterial cells "-CIDE": kill bactericide: kills bacteria fungicide: kills fungi Cidal agents: agents that kill cells Chemical control agents damage the plasma membrane, altering its permeability.
Chromatophores
pigment cells that change the color of an organism, allowing it to camouflage
plant life cycle
plants have alternating generations with two multicellular stages 1 & 9): Spores 2.) Gametophyte (n) 3.) EGG/SPERM 4.) Fertilization 5.) Zygote 6.) Mitosis 7.) Sporophyte 8.) Meiosis 9 & 1.) Spores
Fibrinogen
plasma protein that is converted to fibrin in the clotting process
Resistance factors (R factors)
plasmids that encode for antibiotic resistance
microbial death curve
plotted through logarithms; shows a constant death rate as a straight line Plotting microbial death rates are usually conveyed as a comparison of time and logarithmic death rates. Each logarithm decrease indicates that 90% of the population at the time has been killed. DIAGRAM The blue line, which shows the death rate arithmetically, is less practical as the time progresses to interpret the data. The red line, which in contrast uses logarithms, produces a straight line.
obligate anaerobes
poisoned by oxygen
Antifungal drugs
polyenes and azoles; they target plasma membrane of fungi
membrane filters
porous membranes with defined pore sizes that remove microorganisms primarily by physical screening removes microbes that are greater in size than 0.22 μm
activated fragments
portions of proteins; indicated with lowercase "a" and "b" These portions arise when a protein is cleaved (split apart) EXAMPLE •Antibodies bind to antigens, activating C1 •C1 splits and activates C2 and C4 •C2a and C4b combine and activate C3 (NOTE the cascading effect) C3 can be cleaved into C3a (which helps cause inflammation) and C3b (coates the antigen is coated with the newly produced proteins. This coat possesses binding sites that help phagocytes ingest the entire bacteria.)
complex virus
possesses a capsid which is neither purely helical, nor purely icosahedral, and which may have extra structures such as protein tails or a complex outer wall bacteriophage
immersion oil
possesses the same refractive index as glass; placed in between the microscope and the specimen to keep light from refracting
Robert Hooke (1665)
postulated that living things are composed of little boxes, or "cells" •catalyst of *cell theory*: All living things are composed of cells
Germ Theory of Diseases
postulates micro-organisms This theory *contradicts* the Spontaneous Generation theory. the currently accepted scientific theory for many diseases; It states that pathogens or "germs" can lead to disease. These very small organisms invade living hosts. Their growth and reproduction within their hosts can cause disease. The term "*germ*" refers to *bacterium* and any other type of *microorganism* including *non-living pathogens* that can cause disease, such as *protists*, *fungi*, *viruses*, *prions*, and *viroids*. Basic forms of germ theory were proposed in the late Middle Ages by physicians including Ibn Sina in 1025, Ibn Khatima and Ibn al-Khatib in the 14th century, and Girolamo Fracastoro in 1546, and expanded upon by Marcus von Plenciz in 1762. However, such views were held in disdain in Europe, where Galen's *miasma theory* remained dominant among scientists and doctors. The nature of this doctrine prevented them from understanding how diseases actually progressed, with predictable consequences. By the early nineteenth century, smallpox vaccination was commonplace in Europe, but doctors were unaware of how it worked or how to extend the principle to other diseases. A transitional period began in the late 1850s with the work of Louis Pasteur. This work was later extended by Robert Koch in the 1880s. Viruses were discovered in the 1890s. By the end of the 1880s, the miasma theory was struggling to compete with the germ theory of disease. Eventually, a "golden era" of bacteriology ensued, during which the theory quickly led to the identification of the actual organisms that cause many diseases.
Viremia
presence of viruses in the blood
osmotic pressure
pressure that must be applied to prevent osmotic movement across a selectively permeable membrane uses salts and sugars to create a hypertonic environment; causes plasmolysis
carbolfuchsin
primary stain in acid fast stain; Red dye containing phenol
malachite green
primary stain in endospore stain
crystal violet
primary stain in gram stain purple: gram positive, peptidoglycan is present in the outside layer of the cell pink: gram negative, thin peptidoglycan layer
gel electrophoresis
procedure used to separate and analyze DNA fragments by placing a mixture of DNA fragments at one end of a porous gel and applying an electrical voltage to the gel
gel electrophoresis
procedure used to separate and analyze DNA fragments by placing a mixture of DNA fragments at one end of a porous gel and applying an electrical voltage to the gel • separate DNA fragments according to their size • DNA samples are loaded into wells (indentations) at one end of a gel, and an electric current is applied to pull them through the gel • DNA fragments are negatively charged, so they move towards the positive electrode. Because all DNA fragments have the same amount of charge per mass, small fragments move through the gel faster than large ones. • When a gel is stained with a DNA-binding dye, the DNA fragments can be seen as bands, each representing a group of same-sized DNA fragments.
structural staining
procedures stain a particular structural component of a bacterial cell one color while the bacterial cell is stained a contrasting color; used to observe capsule, spores and flagella used to identify cell components that aren't easily identified through conventional staining
lysogenic
process (cycle) in which a virus embeds its DNA into the DNA of the host cell, which is replicated along with the host cell's DNA •These phages incorporate its DNA into host cell's DNA •Inserted phage DNA is known as a prophage •When the host cell replicates its chromosome, it also replicates prophage DNA. In this condition, the infected bacterium continues to live and reproduce normally. The genetic material of the bacteriophage, called a prophage, can be transmitted to daughter cells at each subsequent cell division. Later events (such as UV radiation or the presence of certain chemicals) can release it, causing the proliferation of new phages via the lytic cycle. Bacteriophage Lambda (λ) is an eminent bacteriophage that uses this cycle. NOW OR LATER? The difference between lysogenic and lytic cycles is that in lysogenic cycles the spread of the viral DNA occurs through the usual prokaryotic reproduction, whereas a lytic cycle is more immediate in that it results in many copies of the virus being created very quickly and the host cell is destroyed. LYSOGENIC: The infection occurs later because the lysogenic virus subtly incubated itself before releasing. LYTIC: The infection occurs relatively quickly because lytic viruses don't give a f*ck about stealth. They go in guns blazing.
Filtration
process in which a filter separates materials based on the size of their particles. •Used for heat-sensitive materials FILTER SIZES •High-efficiency particulate air (HEPA) filters remove microbes that are greater in size than 0.3 μm •Membrane filters remove microbes that are greater in size than 0.22 μm
Translation
process in which mRNA is decoded and a protein is produced PROKARYOTES V EUKARYOTES •In eukaryotes, transcription occurs in the nucleus, whereas translation occurs in the cytoplasm •In bacteria, translation can begin before transcription is complete > mRNA is decoded in the ribosome decoding center to produce a specific amino acid chain, or polypeptide. The polypeptide later folds into an active protein and performs its functions in the cell. > The ribosome facilitates decoding by inducing the binding of complementary tRNA anticodon sequences to mRNA codons. The tRNAs carry specific amino acids that are chained together into a polypeptide as the mRNA is passed through and read by the ribosome. > occurs in the cytoplasm THREE Consecutive STAGES 1.) Initiation Stage 2.) Elongation Stage 3.) Termination Stage •Codons are groups of three mRNA nucleotides that code for a particular amino acid •61 sense codons encode the 20 amino acids •The genetic code involves degeneracy, meaning each amino acid is coded by several codons •Translation of mRNA begins at the start codon: AUG •Translation ends at nonsense codons: UAA, UAG, UGA •Codons of mRNA are "read" sequentially •tRNA molecules transport the required amino acids to the ribosome •tRNA molecules also have an anticodon that base-pairs with the codon •Amino acids are joined by peptide bonds •Exons are regions of DNA that code for proteins •Introns are regions of DNA that do not code for proteins •Small nuclear ribonucleoproteins (snRNPs) remove introns and splice exons together
transformation
process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria •genes transferred from one bacterium to another as "naked DNA"
IFN-α and IFN-β
produced by cells in response to viral infections; cause neighboring cells to produce antiviral proteins (AVPs) that inhibit viral replication
peroxide anion (O2 2-)
produced when free radicals react with hydrogen ions toxic to cells; Hydrogen peroxide can be used as an antimicrobial agent. CATALASE REACTION 2 H2O2 = 2 H2O + O2 PEROXIDASE REACTION H2O2 + 2(H^+) = 2 H2O
spikes
projections from outer surface of a capsid of some viruses. These projections are able to bind with plasma membranes of certain microbes, like a lock-and-key mechanism. (The spikes can only bind to some microbes rather than all microbes.) If the spikes are able to attach to the plasma membrane of another microbe, the virus can then inject its self-replicating compound into the other microbe.
Bacteria
prokaryotic, single-celled microbes lacking chlorophyll and a nucleus One of the two *prokaryotic* *domains* •Peptidoglycan cell walls •Derive nutrition from organic or inorganic chemicals or photosynthesis reproduce via *binary fission*
Histones
protein molecules which keep DNA tightly coiled as chromatin. can form octamers around which DNA is wound to form a nucleosome
interferon
protein produced by cells in response to being infected by a virus; helps other cells resist the virus • Imiquimod: Promotes interferon production
Exotoxins
proteins bacteria secrete into their environment that poisons other organisms •Soluble in bodily fluids; destroy host cells and inhibit metabolic functions TYPES •Membrane-disrupting toxins •Superantigens •Genotoxins RELATED TERMS •Antitoxins: antibodies against specific exotoxins •Toxoids: inactivated exotoxins used in vaccines
Tumor necrosis factor (TNF)
proteins secreted by macrophages and T cells to kill tumor cells and regulate immune responses and inflammation; but in autoimmune diseases like rheumatoid arthritis these can be detrimental rather than helpful
Porins
proteins that allow the passage of certain ions and small polar molecules through membranes
Siderophores
proteins that binds and transports iron in microorganisms across cell membranes • secreted by pathogens that bind iron more tightly than host cells • Iron is required for most pathogenic bacteria.
antiviral proteins (AVPs)
proteins triggered by alpha and beta interferons that prevent viral replication
Bergey's Manual of Systematic Bacteriology
provides phylogenetic information on bacteria and archaea (based on rRNA sequencing) Prokaryotic species: the population of cells with similar physical, biochemical, and genetic characteristics •Culture: bacteria grown in laboratory media •Clone: population of cells derived from a single parent cell •Strain: genetically different cells within a clone
umbonate (elevation)
raised in center with edges almost flat to raised
Calvin Cycle
reactions of photosynthesis in which energy using ATP NADPH is used to build high-energy compounds, mainly sugars (G3P) CO2, ATP, and NADPH are used to form glucose. NADPH adds electrons 3 CO2 enter the cycle in order to make glyceraldehyde 3-phosphate reduction/anabolic reactions occur when carbons reduce to carbohydrates by the addition of electrons or hydrogen occurs in stroma
light-dependent reactions
reactions of photosynthesis that use energy from light to produce ATP and NADPH Photosystem II Photosystem I
Ferredoxin
receives electrons from photosystem I and passes them to NADP reductase
eosin
red
erthrocytes (RBC)
red blood cells (RBC) •Created in red bone marrow stem cells via hematopoiesis
D antigen
red blood cells may have this antigen (a glycolipid) present on their surfaces; they trigger an immune response when they interact with anti-D antibodies • This Rh factor antigen (Rh+) is found on RBCs of 85% of the population
Antibody-dependent cell-mediated cytotoxicity (ADCC)
refers to when antibodies that attach to an antibody of a pathogen cause macrophages, eosinophils, and NK cells to destroy the pathogen NK CELL •The Fc receptors of an NK cell can recognize specific antibodies. If such an antibody is bound to a pathogen, cross-linkage of the Fc receptors occurs, causing the NK cell to kill the pathogen. The pathogen dies of apoptosis. PROTOZOANS / HELMINTHS Protozoans and helminths are too large to be phagocytized. Because of this the protozoan or helminth is coated with antibodies. Then, cells of the immune system cells attach to the Fc regions of these antibodies. This causes the target cells of the protozoan or helminth to be lysed by chemicals secreted by the immune system cells.
thymine dimers
refers to when ultraviolet light damages DNA, causing thymines to covalently bond with adjacent thymines in the same strand instead of the corresponding adenines of the opposite strand
tissue repair
regeneration and fibrosis •Cannot be completed until all harmful substances are removed or neutralized •Stroma is the supporting connective tissue that is repaired •Parenchyma is the functioning part of the tissue that is repaired
DNA gyrase (topoisomerase)
relaxes supercoiling tension ahead of the replication fork
discharge
release or evacuation •Peristalsis, defecation, vomiting, diarrhea
Antisepsis
removal of pathogens from living tissue
DNA Polymerase I
removes the RNA primer and replaces it with DNA in the 5' to 3' direction, which is away from the replication fork. Since the fork continuously splits the strands, DNA Polymerase I can only create the complimentary strands in small chunks.
fastidious organisms
require many, specific growth factors provided in chemically defined media fastidious: "difficult to please"
obligate aerobes
require oxygen
Microaerophiles
require oxygen concentration lower than air
Trace elements
required by an organism in only minute quantities •Inorganic elements required in small amounts •Usually incorporated as enzyme cofactors •Include iron, copper, and zinc
direct contact transmission
requires close association between infected and susceptible host (person-to-person)
rheumatoid
resembling painful changes in the joints
Waxy lipid (mycolic acid)
resists digestion
M protein
resists phagocytosis
membrane ruffling
result of disruption in the cytoskeleton of the host cell
mutant
resulting from or showing the effect of mutation •Positive (direct) selection: beneficial traits; detects mutant cells because they grow or appear different than unmutated cells •Negative (indirect) selection: detrimental traits; detects mutant cells that cannot grow or perform a certain function •Auxtotroph: mutant that has a nutritional requirement absent in the parent •Use of replica plating
hydroxyl radical
results from ionizing radiation and from an incomplete reduction of Hydrogen Peroxide OH; the neutral form of hydroxide ion (OH^-)
helical viruses
rod-shaped viruses
circular (form)
round with even borders
Isopropanol
rubbing alcohol
platelet plug formation
sealing of the ruptured blood vessel
Gelatin Hydrolysis
secretion of gelatinase by microbes to hydrolyze gelatin negative=dark blue, starch present positive= lack blue color, starch hydrolyzed
promoter site
section of a DNA molecule that indicates where the sequence of base pairs that makes up a gene begins RNA polymerase binds at this site in order to begin the initiation stage of transcription
termination site
section of a DNA molecule which indicates that the RNA polymerase will conclude the transcription of an RNA strand
Oxidative Phosphorylation (Electron Transport Chain, ETC)
series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions -4th step of cellular respiration As electrons trickle "downhill" through the transport chain, they release energy, and some of this energy is captured in the form of an electrochemical gradient and used to make ATP. Site of ETC -Eukaryotic cells: mitochondria -Prokaryotic cells: plasma membrane 4 protein subunits and cytochromes shuttle electrons through ETC. NADH and FADH2 carry electrons to the electron transport chain.
RNA primer
short segment of RNA, about 5-10 nucleotides long, that base-pairs with the template strand DNA strand will start forming at this 3' end of the primer, which is used to initiate synthesis of a new strand of DNA during replication.
erose (margin)
short uneven indentations
Thermal death time (TDT)
shortest length of time required to kill all test microbes at a specified temperature
monomorphism
single shape
coccus (cocci)
single spherical shaped bacteria
ribonucleic acid (RNA)
single-stranded nucleic acid that contains the sugar ribose •Single-stranded nucleotide •5-carbon ribose sugar •Contains uracil (U) instead of thymine (T) Ribosomal RNA (rRNA): integral part of ribosomes Transfer RNA (tRNA): transports amino acids during protein synthesis Messenger RNA (mRNA): carries coded information from DNA to ribosomes
pyruvate oxidation
site in which pyruvate oxidation process occurs: eukaryotes: mitochondrial matrix prokaryotes: cytoplasm
Ribosomes
site of protein synthesis •Made of protein and ribosomal RNA •70S •50S + 30S subunits The unit of measurement used to describe the ribosomal subunits and the rRNA fragments is the Svedberg unit, a measure of the rate of sedimentation in centrifugation rather than size. This accounts for why fragment names do not add up: for example, bacterial 70S ribosomes are made of 50S and 30S subunits.
reservoirs of infection
sites where pathogens are maintained as a source of infection; these sites encourage the growth of and help sustain the pathogens •Human reservoirs Carriers may have inapparent (subclinical) infections or latent diseases •Animal reservoirs Zoonoses are diseases transmitted from animals to humans •Nonliving reservoirs things such as soil, air, and water
bacterial cells
size 0.2 to 2.0 μm diameter 2 to 8 μm length μm: micrometer (10^6); 1,000,000 meters shapes Most bacteria are monomorphic, meaning they only appear as one consistent shape; A few are pleomorphic, meaning they can adopt many shapes. •Bacillus (rod-shaped) •Coccus (spherical) •Spiral •Vibrio (curved rod, like a comma) •Spirillum (rigid spiral, like waves) •Spirochete (squiggly line) •Star-shaped •Rectangular
epithelial cells
skin cells that cover the outside of the body and line the internal surfaces of organs
platelet
small blood fragment that collects at sites of injury to begin the clotting process
Plasmids
small circular DNA molecules that replicate separately from the bacterial chromosome that carries advantageous but non-vital genes can be gained or lost without harming the cell (e.g., antibiotic resistance, production of toxins)
plasmids
small circular DNA molecules that replicate separately from the bacterial chromosome; they're like modules in the sense that they provide benefits, but aren't required. •self-replicating, circular pieces of DNA •1 to 5% the size of a bacterial chromosome •Often code for proteins that enhance the pathogenicity of a bacterium •Conjugative plasmid: carries genes for sex pili and transfer of the plasmid •Resistance factors (R factors): encode antibiotic resistance
hapten
small molecule that has to bind to a larger molecule to form an antigen
capillary
smallest blood vessel; brings nutrients and oxygen to the tissues and absorbs carbon dioxide and waste products
dendritic cells
specialized agranular white blood cells (leukocytes) that patrol the body searching for antigens that produce infections; phagocytic FOUND IN * skin * mucous membranes * thymus
Gamete
specialized cell involved in sexual reproduction
intermediate
species that appear in some steps but not in the net equation; they are produced then later consumed. Contrast this with a catalyst, which is produced but not consumed.
humoral immunity
specific immunity in which B cells produce antibodies, complement proteins, and certain antimicrobial peptides.that circulate in body fluids
humoral immunity
specific, adaptive immunity in which B cells produce antibodies that circulate in body fluids; this kind of immunity fights infections outside of the host cells rather than in them. • production of antibodies, which fight antigens (foreign molecules) • Bacteria and toxins are often targeted. • B cells: lymphocytes created and matured in red bone marrow • recognition of antigens and subsequent production of antibodies
spirilium
spiral shaped bacteria
spirochete bacteria
spiral shaped bacteria
Granum
stack of thylakoids
G1 phase
stage of interphase in which cell grows and performs its normal functions On average, a cell spends around 90% of its life in G1.
flourescence
stained with fluorescent molecule and illuminated with light of a certain wavelength
basic stains
staining solution with a positively charged chromophore; most bacteria are negatively charged methylene blue crystal violet fuchsin malachite green safranin
collision theory
states that atoms, ions, and molecules must collide in order to cause chemical reactions Activation energy: the collision energy required for a chemical reaction to begin. Reaction rate: the frequency of collisions containing enough energy to bring about a reaction •Reaction rate can be increased by enzymes or by increasing temperature, pressure, or concentration
Moist Heat Sterilization
sterilization techniques that use hot air heavily laden with water vapor: this moisture plays the most important role in this sterilization. •Moist heat denatures proteins •Boiling •Free-flowing steam Autoclave: a device that causes steam to be under pressure •121 C at 15 psi for 15 min •Kills all organisms and endospores •Steam must contact the item's surface •Large containers require longer sterilization times •Test strips are used to indicate sterility
activated complement proteins
stimulate chemotaxis, promote agglutination, make pathogens more susceptible to phagocytosis, and encourage lysis
bladder
stores urine
collagen
structural protein found in the skin and connective tissue
Tetrad
structure containing 4 chromatids that forms during meiosis
Pathology
study of diseases pathogen: an organism that causes disease
Etiology
study of the cause of disease
Immunology
study of the immune system
symptoms
subjective sensations or feelings that are reported by the patient; aren't directly observed (Compare with signs, which are directly measured.)
Vaccine
substance prepared from killed or weakened pathogens and introduced into a body to produce immunity TYPES - killed, whole cell or inactivated viruses - Live, attenuated cells or viruses - Antigenic molecules from bacteria or viruses - Genetically engineered microbes or microbial antigens (a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies)
catalyst
substance that speeds up the rate of a chemical reaction without being altered
skin test
substances are injected intradermally or applied to the skin, and results are observed; used to prevent anaphylactic reactions • Antigens are inoculated beneath the epidermis to test for a rapid inflammatory reaction (wheal) • Desensitization: increasing dosages of antigen are injected beneath the skin • Produces IgG, an antibody that blocks, intercepts, and neutralizes antigens
small ribosomal subunit
subunit that recognizes mRNA transcripts and initiates translation Each subunit consists of one or more rRNA molecules and a variety of ribosomal proteins (r-proteins). The ribosomes and associated molecules are also known as the *translational apparatus*.
commercial sterilization
sufficient heat treatment to kill endospores of Clostridium botulinum in canned food
arm
supports tube and connects to base
selective media
suppress unwanted microbes and encourage desired microbes •contain inhibitors to suppress growth •Some media have both selective and differential characteristics
Lymphadenopathy (LAD)
swollen lymph nodes
acute
symptoms develop rapidly but the disease lasts only a short time (example: some lytic viruses)
reverse transcription
synthesis of DNA from an RNA template
Smooth Endoplasmic Reticulum
synthesizes cell membranes, fats, and hormones -endomembrane system -no ribosomes -lipids synthesized -calcium levels regulated -toxic substances broken down -Carbohydrate metabolism -Ca2+ ion storage travel across ER membrane into cytosol to trigger muscle contraction
antimicrobial drugs
synthetic substances that interfere with the growth of microbes POSSIBLE EFFECTS Inhibiting cell wall synthesis • Penicillin prevent the synthesis of peptidoglycan Injuring the plasma membrane • Polypeptide antibiotics change membrane permeability • Antifungal drugs combine with membrane sterols Inhibiting nucleic acid synthesis • by interfering with DNA replication and transcription (inhibits DNA gyrase) Inhibiting the synthesis of essential metabolites • Antimetabolites compete with normal substrates for an enzyme • Sulfanilamide competes with para-aminobenzoic acid (PABA), stopping the synthesis of folic acid
misuse
taking or using medicine (antibiotics) in a way that is not intended EXAMPLES • using outdated or weakened antibiotics • using antibiotics for the common cold and other inappropriate conditions • using antibiotics in animal feed • failing to complete the prescribed regimen • using someone else's leftover prescription
candle jar
technique in which a lit candle is placed in an air-tight jar. It goes out it when it uses up all the available oxygen The candle in the jar is lighted prior to the incubation of the jar at 37 C. The flame goes out as oxygen is consumed, resulting in a 5-10% CO2 atmosphere.
heat fixation
technique used to adheres a substance to a slide, kills any living bacteria near the slide, and preserves the shape of the substance (usually cells). Pass a slide through the flame of a Bunsen burner 3 times. Do not hold in flame or will break slide.
immunoglobins (Ig) (antibodies)
term synonymous with antibody; a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses
Immunologic-based diagnostic tests
tests that involve interactions of humoral antibodies with antigens known antibodies can be used to identify an unknown pathogen; known pathogens can identify an unknown antibody
Spontaneous generation
the (incorrect) hypothesis that life arises from nonliving matter; a "vital force" is necessary for life
immunity
the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells.
Neutralization
the ability of antibodies to bind and block the site(s) of a pathogen that they use to attack or invade the target cell (Competitive/Non-competitive inhibition)
efficacy
the ability of drug to achieve a desired effect (Compare with potency, the amount of drug required to achieve a desired effect)
Pleomorphism
the ability of some micro-organisms to alter their morphology (shape), biological functions, or reproductive modes in response to environmental conditions
energy
the ability to do work or produce heat •the energy for replication comes from nucleotides •the hydrolysis of two phosphate groups on ATP provides energy
Margination (pavementing)
the adherence of phagocytes (leukocytes) to the endothelial cells of blood vessels in response to cytokines at the site of inflammation
Booster dose
the amount of immunogen injected at an appropriate interval after the primary immunization to sustain the immune response to that immunogen • usually smaller than the initial amount TYPES OF IMMUNOGEN • vaccine • toxoid • other antigen preparations
alcoholic fermentation
the anaerobic process by which yeasts and other microorganisms break down sugars to form carbon dioxide and ethanol
monoclonal antibodies (Mabs)
the antibodies produced by a hybridoma; these antibodies are therefore identical in structure and antigen specificity to the precursor B cell antibodies PURPOSE • They are continuously produced since hybridoma lack contact inhibition • Mabs are uniform, highly specific, and produced in large quantities APPLICATION • Used in diagnostic tools • Used in human therapy • Neutralize TNF when afflicted with rheumatoid arthritis • Treat allergic asthma by preventing the binding of IgE on mast cells and basophils Since they are often derived from mouse cells, they can leading to side effects.
Autoantigens
the antigens that a diseased immune system doesn't tolerate when it should such as such as an organism's own tissue or insignificant things; some antigens should be tolerated in certain amounts (see systematic autoimmunity and hyperactivity)
zone of inhibition
the area around an antibiotic where the antibiotic visibly inhibits bacterial growth
nucleosome
the basic structural unit of DNA packaging in eukaryotes Its structure consists of a segment of DNA wound around eight histone proteins and resembles thread wrapped around a spool. DNA must be compacted into nucleosomes to fit within the cell nucleus. In addition to nucleosome wrapping, eukaryotic chromatin is further compacted by being folded into a series of more complex structures, eventually forming a chromosome.
Carbohydrate Metabolism
the breakdown of carbohydrate molecules to produce energy Liver 1.) Glycolysis 2.) Krebs cycle 3.) Electron transport chain (system)
Glycolysis
the breakdown of glucose by enzymes, releasing energy and pyruvic acid(pyruvate) Some H+ can diffuse through the membrane without ATP synthase. Some energy is used to move NADH from the cytoplasm to the mitochondria. -First step of cellular respiration Occurs in cytoplasm 6 carbon glucose --> 3 carbon pyruvate 2 ATP --> 4 ATP required input: 2 ATP produced by substrate-level phosphorylation
Metabolism (biotransformation)
the buildup and breakdown of nutrients within a cell •These chemical reactions provide energy and create substances that sustain life Catabolism breaks down complex molecules; provides energy and building blocks for anabolism; exergonic Anabolism uses energy and building blocks to build complex molecules; endergonic Metabolic pathways sequences of enzymatically catalyzed chemical reactions in a cell •Enzymes catalyze (accelerate) chemical reactions The molecules at the beginning of the process are called substrates and the enzyme converts these into different molecules, called products.
Therapeutic Index (TI)
the calculated risk versus benefits of using a drug or (such as an antibiotic) • This index compares the ratio of LD50 (lethal dose for 50% of a population) to ED50 (effective does for 50% of a population)
lethality
the capability of causing death (Compare with severity)
lactic acid fermentation
the chemical breakdown of carbohydrates that produces lactic acid as the main end product
lactic acid fermentation
the chemical breakdown of carbohydrates that produces lactic acid as the main end product •Glucose is oxidized to pyruvic acid, which is then reduced by NADH TYPES •Homolactic fermentation: produces lactic acid only •Heterolactic fermentation: produces lactic acid and other compounds
ABO blood group system
the classification of human blood based on the inherited properties of red blood cells (erythrocytes) as determined by the presence or absence of the antigens A and B, which are carried on the surface of the red cells. • Thus, people can have type A, type B, type O, or type AB blood.
compliment system
the cleaving (splitting apart) of proteins into smaller proteins or activated fragments; these smaller components have different properties than the original system and can further divide EXAMPLE 1.) Antibodies bind to antigens, activating C1 2.) C1 splits and activates C2 and C4 3.) C2a and C4b combine and activate C3 • NOTE the cascading effect 4.) C3 can be cleaved into C3a (which helps cause inflammation) and C3b (coates the antigen is coated with the newly produced proteins. • This coat possesses binding sites that help phagocytes ingest the entire bacteria.
Opsonization
the coating of an antigen with antibodies to enhances the immune system phagocytosis of the pathogen • occurs when serum proteins are modified (via cascading), becoming antibodies
genetic code
the collection (sequence) of codons of mRNA, each of which directs the incorporation of a particular amino acid into a protein during protein synthesis a "set of rules" that determines how a nucleotide sequence is converted to an amino acid sequence of a protein
Microbiome
the collection of microorganisms that live in a particular environment, such as a human body. •Human Microbiome: Project analyzes relationships between microbial communities on the body and human health
immune complex (Type III) hypersensitivity
the combinations of an antibody and antigen that produces a complex that can initiate a hypersensitivity reaction
human microbiome
the complete collection of microorganisms in the human body's ecosystem; these communities consist of a variety of microorganisms including eukaryotes, archaea, bacteria, and viruses that live in tangent with the human body. These microbes are generally not harmful, greatly outnumber human body cells, and most of them are essential for maintaining health. Bacteria in the human body number ten times more than human cells, for a total of about 1,000 more genes than are present in the human genome. Because of their small size, however, microorganisms make up only about 1 to 3 percent of our body mass (that's 2 to 6 pounds of bacteria in a 200-pound adult).
genome
the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes Every cell of an organism possesses the same genome, but they only use certain parts of it.
artificial selection
the controlled breeding of organisms with specific traits in order to produce offspring with identical, useful traits •Positive (direct) selection: beneficial traits; detects mutant cells because they grow or appear different than unmutated cells •Negative (indirect) selection: detrimental traits; detects mutant cells that cannot grow or perform a certain function
transduction
the conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret
base modification
the covalent modification of a base within an RNA molecule The nitrogenous RNA bases occupy different places than the ones they originated.
Virulence
the degree of pathogenicity "How easily does it cause infection?"
immune surveillance
the destruction of abnormal cancer cells by NK cells in peripheral tissues • Cancer cells have tumor-associated antigens that the immune system (NK, CTL) associate with harmful substances • CTLs (cytotoxic T lymphocyte, activated by CD8+) and macrophages lyse the cancer cells PROBLEMS • When the cancer cells reproduce too rapidly, there isn't a consistent antigenic epitope for the immune system to target. • When a tumor becomes vascularized (connected to the body's blood supply), the immune system fails to recognize it (invisible to the immune system).
sympathetic nervous system
the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
rapid efflux
the ejection pumps in plasma membrane of microbe that pump out the antimicrobial before it works
antibiotic resistance
the evolving resistance of antibiotics in many species of prokaryotes due to overuse of antibiotics, especially in agriculture. • a modern, worsening problem
genetic recombination
the exchange of genes between two DNA molecules; creates genetic diversity
treatments
the experimental conditions imposed by the experimenter Effectiveness of treatment depends on: •Number of microbes •Environment (organic matter, temperature, biofilms, etc.) •Time of exposure •Microbial characteristics
osmotic pressure
the external pressure that must be applied to stop osmosis; the pressure needed to stop the movement of water across the membrane
antigen-antibody complex
the formation that occurs when one or more antibodies bind to an antigen; this complex alerts the immune system of the presence of the antigen. The foreign substance is then destroyed TYPES • Agglutination • Opsonization • Antibody-dependent cell-mediated cytotoxicity • Neutralization • Activation of the complement system The affinity of the complex refers to the strength of the bond(s) between the antibody and the antigen.
Septicemia (blood poisoning)
the growth of bacteria in the blood; this means there is an infection in the blood
delayed cell-mediated (Type IV) hypersensitivity
the hypersensitivity reaction takes several days to develop; unlike the other types, this is a cell-mediated response rather than antibody-mediated. • This response involves the interaction of T-cells, monocytes, and macrophages. • The overreaction of the helper T cells and overproduction of cytokines results in the damage of tissues, causes inflammation, and cell death but can usually be resolved with topical corticosteroids and trigger avoidance.
Biogenesis
the hypothesis that living cells arise only from pre-existing living cells
Heterotrophy
the inability of an organism to synthesize its own food and is dependent on consuming complex organic substances for nutrition
Acquired immunodeficiency
the inability, obtained during the life of an individual, to produce specific antibodies or T cells, due to drugs or disease (such as AIDS)
adernal medulla
the inner part of the adrenal glands that controls stress-activated hormones: • Epinephrine • norepinephrine
intercalators
the insertion of molecules between the planar bases of DNA; the basis of certain kinds of poisoning IDIOT EXPLANATION chemical mutagens composed of flat, planar molecules that "sandwich" themselves between successive base pairs and disrupt the machinery of replication, recombination, or repair.
synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
Anaphase
the kinetochore microtubules contract, seperating the sister chromatids and moving them to the centrioles at the opposite ends of the cell. Meanwhile, polar microtubules lengthen, pushing the poles apart which in turn separate the cell into daughter cells.
host range
the limited range of host cells that each type of virus can infect •Most viruses infect only specific types of cells in a host; this is determined by specific host attachment sites and cellular factors
minimal bactericidal concentration (MBC)
the lowest concentration of chemotherapeutic agent that will kill test microorganisms
Thermal death point (TDP)
the lowest temperature required to kill all microbes in a sample in 10 minutes
memory cells
the lymphocytes that are responsible for immunological memory and protective immunity They live for long periods of time and are capable of responding to a particular antigen in the event of its reintroduction, long after the exposure that prompted its production (Compare with effector cells)
Microbiota
the microbes that aren't of the human but are normally present in and on the human body; essential for life and most species are beneficial Normal microbiota compete with pathogens via microbial antagonism •production of substances harmful to pathogens •altering conditions that affect the growth of pathogen •Commensalism: one organism benefits while the other (host) is unharmed •Probiotics: live microbial cultures administered to exert a beneficial effect
fermentation (anaerobic respiration)
the microbial *conversion of sugar to alcohol* in the *absence* of air; enables cells to produce ATP without the use of oxygen •Pasteur showed that microbes are responsible for fermentation •Microbial growth is responsible for spoilage of food and beverages •Bacteria that use air spoil wine by turning it to vinegar (acetic acid)
Agglutination (aggregation)
the migration and clumping of blood cells or pathogens due to an antigen-antibody interaction or compliment-protein interaction As pathogens are trapped in these aggregated clumps, they can be consumed by phagocytosis all at once, rather than individually.
substrate
the molecules upon which enzymes convert into different molecules, products Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life.
active transport
the movement of ions or molecules across a cell membrane into a region of higher concentration; assisted by enzymes and requires energy. requires a transporter protein and ATP; goes against gradient In passive transport, substances cross the cell membrane without the cell expending energy, but in active transport, substances are moved against a concentration difference at the cost of energy. •Active processes: substances move from low concentration to high concentration; energy is expended
effector cells
the muscle cells or gland cells that actually carry out the body's responses to stimuli. (COMPARE with MEMORY CELLS)
Norepinephrine (NE)
the neurotransmitter used by the sympathetic division of the autonomic nervous system at the post-ganglionic organ-level; synapse Mainly excitatory; involved in arousal, mood, hunger, and sleep
prevalence
the number or proportion of cases of a particular disease or condition present in a population at a given time •Regardless of when the disease first appeared, this term can mean to account for both old and new cases.
epitopes
the part of an antigen molecule to which an antibody attaches itself; antigenic determinants that stimulate the immune response
mechanical transmission
the passive transport of the pathogens on the insects feet or other body parts
osmotic pressure
the pressure that must be applied to the prevent osmotic movement of particles across a selectively permeable membrane •Hypertonic environments (higher solute concentration of the environment than inside the cell) cause cells submerged to undergo plasmolysis (cells shrivel due to water exiting the cell) due to the high osmotic pressure Extreme or obligate halophiles: require high osmotic pressure (high salt concentration) •Facultative halophiles tolerate high osmotic pressure DIAGRAM Consider the U-Tube in the diagram. The water, a solvent, moves towards the solvent. All of the solvents are on one side of the tube. There is a selectively-permeable membrane dividing the tube into two symmetrical halves. Water can pass through it since the molecules are small enough and polar, but salt can't. Water must pass through the membrane in order to meet the other side of the tube. The water will not all move to one side, even though the salt is isolated to one side of the tube. This is true regardless of the amount of salt. Osmotic pressure prevents all of the water from traveling to one side of the tube.
First line of defense
the primary systems of defense against pathogens COMPRISED OF micriobiota (including probiotics) skin (epidermis, dermis) mucous membranes (mucous) chemical factors (sebum, lysozyme, pH) physical factors (skin, shedding, mucous, Lacrimal apparatus, ciliary escalator, earwax, urine, vaginal secretion, Peristalsis, discharge)
phagocytic
the process by which cells surround and digest certain particles, meaning toxic in particular against parasties and helminths
cellular respiration
the process by which cells use oxygen to produce energy from food oxidation reaction in which glucose is oxidized and oxygen is reduced
gene expression
the process by which information from a gene is used in the synthesis of a functional gene product. These products are often *proteins*, but in non-protein coding genes such as transfer RNA (tRNA) or small nuclear RNA (snRNA) genes, the product is a functional RNA. >used by all known life—eukaryotes, prokaryotes, and even viruses—to generate the macro-molecular machinery for life. >Several steps in the process may be modulated, including the transcription, RNA splicing, translation, and post-translation modification of a protein. >gives the cell control over structure and function, and is the basis for cellular differentiation, morphogenesis, and the versatility and adaptability of any organism. Also serves as a substrate for evolutionary change, since control of the timing, location, and amount of gene expression can have a profound effect on the functions (actions) of the gene in a cell or in a multi-cellular organism. >the most fundamental level at which the genotype gives rise to the phenotype. The genetic code stored in DNA is "interpreted" by gene expression, and the properties of the expression give rise to the organism's phenotype. Such phenotypes are often expressed by the synthesis of proteins that control the organism's shape, or that act as enzymes catalyzing specific metabolic pathways characterizing the organism.
DNA replication
the process of making a copy of DNA •DNA forms a double helix •The "backbone" of DNA is deoxyribose-phosphate •Two strands of nucleotides are held together by hydrogen bonds between A-T and C-G •Strands are anti-parallel •Order of the nitrogen-containing bases forms the genetic instructions of the organism *semi-conservative*, because the new double helix is composed of two single-strands. One strand possesses the same pattern as the original one. The other is unique. *HUMANS* ■46 chromosomes ■6 billion nucleotide pairs ■DNA replication only takes a few hours -very few mutations (errors) occur during this process
disease prevention
the process of reducing risks and alleviating disease to promote, preserve, and restore health and minimize suffering and distress Reduce number of pathogens by: •Handwashing •Disinfecting tubs used to bathe patients •Cleaning instruments •Using disposable bandages and intubation Infection control committees
Lipid catabolism (lipolysis)
the process of splitting triglycerides into fatty acids and glycerol MEMORIZE THE DIAGRAM
Pasteurization
the process of treating a substance with heat to destroy or slow the growth of pathogens; reduces spoilage Equivalent treatments •63 C for 30 min •High-temperature short-time (HTST): 72 C for 15 sec •Ultra-high-temperature (UHT): 140 C for 4 sec Thermoduric organisms, however, can survive.
Spermatogenesis
the production of sperm cells
Oogenesis
the production, growth, and maturation of an egg, or ovum
Apoenzyme
the protein portion of an enzyme; doesn't include the coenzyme or substrate The apoenzyme is inactive since by definition it doesn't include a coenzyme or substrate.
complement activation
the reaction of the body's immune system to protect it from microorganisms and foreign substances; proteins making up compliment system are activated, stimulating inflammation RESULTS AND EFFECTS Cytolysis •Activated complement proteins create a membrane attack complex (MAC) Opsonization •Promotes attachment of a phagocyte to a microbe Inflammation •Activated complement proteins bind to mast cells, releasing histamine Regulation of complement •Regulatory proteins readily break down complement proteins, minimizing host cell destruction Complement and disease •a lack of complement proteins will cause a great susceptibility to infections Evading the complement system •Capsules prevent complement activation opsonization occurs when serum proteins are modified (by splitting apart, usually) via antibodies and factors. Cascading effect occurs; chain reaction Classical or Alternative Pathway EXAMPLE • Antibodies bind to antigens, activating C1 • C1 splits and activates C2 and C4 • C2a and C4b combine and activate C3 (NOTE the cascading effect) C3 can be cleaved into C3a (which helps cause inflammation) and C3b (coates the antigen is coated with the newly produced proteins. This coat possesses binding sites that help phagocytes ingest the entire bacteria.)
NADH
the reduced form of NAD+; an electron-carrying molecule that functions in cellular respiration •Each molecule can be oxidized in the electron transport chain to produce 3 molecules of ATP •Assist enzymes; electron carrier
Degranulation
the release of the mediators, which are the contents of granules, from mast cell granules
convalescence
the return to health after illness
follicle
the sac in the ovary in which the egg develops. This sac is made of cells.
taxonomy
the science of classifying organisms
Meiosis II
the second phase of meiosis consisting of chromatids separating, along with the two diploid cells splitting in two
transcription start site
the section of DNA where transcription starts, where the first RNA nucleotide is added (at the 5' end of a gene sequence) The site is also known as the *+1 site*. NOTE: A *promoter* is a region of DNA that leads to initiation of transcription of a particular gene. Promoters are located near the transcription start sites of genes, upstream on the DNA. Promoters can be about 100-1000 base pairs long.
passive immunity
the short-term immunity that results from the introduction of antibodies from another person or animal.
microwaves
the shortest wavelengths and the highest frequencies can be utilized in radiation sterilization kills by heat; not especially antimicrobial EXPLANATION Microwave oven frequencies are tuned to match energy levels in water molecules. In the liquid state, water molecules quickly absorb the microwave energy and then release it to surrounding materials as heat. The molecules occupy high-speed motion. The heat of the resulting friction is transferred to foods, which become hot rapidly. Thus, materials that do not contain water, such as plates made of paper, china, or plastic, remain cool while the moist food on them becomes heated.
epitote
the small, accessible portion of an antigen that binds to an antigen receptor; an antigenic determinant • used to determine T-cell / B-cell specificity
Minimum inhibitory concentration (MIC)
the smallest concentration (highest dilution) of drug that visibly inhibits growth
Lacrimal apparatus
the structures that produce, store, and remove tears (REFER TO THE DIAGRAM)
Serology
the study of reactions between antibodies and antigens (a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.)
Systematics (phylogeny)
the study of the evolutionary history of organisms
Para-aminobenzoic acid (PABA)
the substrate for an enzymatic reaction leading to the synthesis of folic acid
adherence (adhesion)
the tendency of dissimilar particles or surfaces to cling to one another an essential step in bacterial pathogenesis or infection, required for colonizing a new host. Adhesion and bacterial adhesins are also a potential target for prophylaxis or treatment of bacterial infections. •Almost all pathogens attach to host tissues through this phenomenon (also known as adhesion) Adhesins (ligands) on the pathogen bind to receptors on the host cells. These receptors include: •Glycocalyx •Fimbriae •Microbes form biofilms (communities that share nutrients) (cohesion refers to the tendency of similar or identical particles to cling to one another).
generation time (doubling time)
the time required for a complete fission cycle, from parent cell to two daughter cells; time required for a cell to divide •20 minutes to 24 hours •Binary fission doubles the number of cells each generation FORMULA Total number of cells = 2^(number of generations) •Growth curves are represented through logarithmic expressions
bacterial conjugation
the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. This takes place through a pilus. It is a mechanism of horizontal gene transfer as are transformation and transduction although these two other mechanisms don't involve cell-to-cell contact. OVERVIEW 1.) There are two bacteria, and they both contain a circular bacterial chromosome. But one of the cells contains a plasmid that the other one doesn't have and wants. This plasmid is a separate strand from the bacterial chromosome and is called the F factor. The donor cell that contains the F factor is called the F+ cell. The recipient is called the F- cell. 2.) The cells connect to each other through a mating bridge. This is a channel formed through melting points. Hfr cells contain the F factor on the chromosome. 3.) The F factor, which is a double strand, is unwound into its two strands. All of this takes place in the F+ cell. 4.) One of the two strands of the F factor is transferred to the F- cell. 5.) Both of the strands synthesize their complementary strand again. The strands become a double-strand. Now the F- cell is now also considered an F+ cell, and the original F+ cell once again has the double-strand K factor. 5.) The "newer" F+ cell undergoes genetic combination with the bacterial chromosome and its new F factor. The F factor integrates with the chromosome, and they become one, making a "new" chromosome. When an F factor becomes integrated into the chromosome of an F+ cell, the cell is considered to be a high frequency of recombination (Hfr) cell. 6.) The Hfr cell binds with another F- cell. 7.) The transfer and replication of parts of the chromosome of the Hfr cell take place. 8.) The F- cell undergoes recombination with its chromosome and the chromosome fragment from the Hfr cell. This F- cell is now considered to be a recombinant F- cell.
fecal transplant
the transfer of microbiota from the colon of one individual into the colon of another • Can be used to treat Clostridium difficile (C-diff)
biological transmission
the transmission of a pathogen from one host to another when the pathogen reproduces in the vector
chemotherapy
the use of drugs to treat a disease
cytopathic effect (CPE)
the visible effect(s) on a host cell caused by a virus that may result in host cell damage or death EFFECTS • cell synthesis STOPS • Causing cell lysosomes to release enzymes •Creating inclusion bodies in the cell cytoplasm • Fusing cells together, creating a syncytium • Changing host cell function or inducing chromosomal changes • Inducing antigenic changes on the cell surface (antigens are usually on the surface of the pathogen; antibodies bind to the antigens) • Loss of contact inhibition in the cell, leading to cancer •the production of interferons
central dogma
theory that states that, in cells, information only flows from DNA to RNA to proteins (DNA -> RNA -> Protein)
subclinical disease (preinfection)
these diseases are subtle, causing no noticeable signs or symptoms; an illness that stays below the surface of clinical detection This is a first stage of illness. The illness can become clinical. (inapparent infection)
Class III MHC genes
they encode various secreted proteins that have immune functions, including components of the complement system and molecules involved in inflammation
latent disease
this disease with a period of no symptoms, meaning the causative agent is inactive; then a period of infections and symptoms, meaning the causative agent is active (Example: lysogenic viruses)
Fuchsin
this stain is used to stain collagen, smooth muscle, or mitochondria.
positive strand RNA (ssRNA +)
this stand of viral RNA possesses the same (positive) polarity as mRNA. This allows genome RNA to be translated in the cytoplasm by host cell ribosomes. ssRNA + : (sense) strand This viral RNA serves as mRNA for protein synthesis.
RNA virus
this type of virus multiplies in the host cell's cytoplasm using RNA-dependent RNA polymerase ssRNA + : (sense) strand This viral RNA serves as mRNA for protein synthesis. ssRNA - : (antisense) strand •The purpose of this viral RNA is to be a template to transcribed + strand RNA. These processes are facilitated by virus enzymes, not host cell enzymes. dsRNA: double-stranded RNA
chromosome
threadlike "coils", gene-carrying structure found in the nucleus condensed chromatin Each chromosome consists of one (very long) DNA molecule and its associated proteins.
Heterochromatin
tightly compacted DNA and proteins, observed in cells that are entering the cell cycle (condense during prophase) Keeps DNA from "tangling" since it must split into 2 daughter cells the "tightness" of the compaction prevents DNA replication components from copying data easily
Decimal Reduction Time (DRT)
time in minutes required to kill 90% of a population at a given temperature
Granule
tiny particles or sacs containing digestive enzymes, compounds, or other chemical substances that contain various enzymes, compounds and other components used to defend against pathogens, reduce inflammation and destroy cells. The main difference between granulocytes and agranulocytes is that granulocytes consist of a granular cytoplasm whereas agranulocytes do not consist of a granular cytoplasm.
Viruses
tiny particles, smaller than bacteria and other pathogens, which must invade living cells in order to reproduce; the cells are damaged or destroyed in the process releasing new particles to infect other cells CLASSIFICATION OF VIRUSES •Not a part of any domain; not composed of cells; requires a host cell •Viral species: population of viruses with similar characteristics that occupies a particular ecological niche
lymphoid tissue
tissue composed of lymphocytes supported by connective tissue • tonsil tissue, lymph nodes, and lymphatic organs
privileged tissue
tissue used for transplant that does not stimulate an immune rejection
Inoculation loop/needle
tool designed to transfer substances; sterilize with fire when transferring microbes
sepsis
toxic inflammatory condition arising from the spread of microbes, especially bacteria or their toxins. These microbes come from a focus of infection. occurs when chemicals are released in the bloodstream to fight an infection-triggered inflammation throughout the body. This can cause a cascade of changes that damage multiple organ systems, leading them to fail, sometimes even resulting in death. Symptoms include fever, difficulty breathing, low blood pressure, fast heart rate, and mental confusion. Treatment includes antibiotics and intravenous fluids.
hydrogen peroxide
toxic to cells and used as a disinfectant; H2O2
Toxemia
toxins in the blood although microbes produce toxins, these aren't the only potential sources EXAMPLE: tetanus EMINENT EXAMPLE A condition in pregnancy, also known as pre-eclampsia (or preeclampsia) characterized by abrupt hypertension (a sharp rise in blood pressure), albuminuria (leakage of large amounts of the protein albumin into the urine) and edema (swelling) of the hands, feet, and face. Pre-eclampsia is the most common complication of pregnancy. It affects about 5% of pregnancies. It occurs in the third trimester (the last third) of pregnancy.
Endotoxins
toxins that are released only when bacteria die and their cell walls break down
vehicle transmission
transmission by an inanimate reservoir, such as food, water, and air
contact transmission
transmission of an infectious agent by contact of the source or its reservoir (host reservoir) TYPES •Direct contact transmission: requires a close association between the infected and a susceptible host •Indirect contact transmission: spreads to a host by a nonliving object called a fomite (utensils, toys, money, thermometers, and diapers) •Droplet transmission: transmission via airborne droplets less than 1 meter
droplet transmission
transmission via airborne droplets of a size less than 1 meter The pathogens are present in the droplets. Droplets are defined as "a very small drop of a liquid."
ciliary escalator
transports microbes trapped in mucus away from the lungs (think of escalators)
biocide (germicide)
treatments designed to kill microbes
Icosahedral
triangular faces arranged around the surface of a hollow sphere containing the nucleic acid. 20-sided with 12 corners
urethra
tube leading from the urinary bladder to the outside of the body; path from which urine is discharged
vas deferens
tube that carries sperm from the epididymis to the urethra
cisternae
tubules and sacs within the ER
myeloma
tumor of the bone marrow; B cells become cancerous
diplococcci
two cocci bacteria stuck together on a single plain
phagocytosis
type of endocytosis in which a cell engulfs large particles or whole cells
cell-mediated immunity
type of immunity produced by T cells that attack infected or abnormal body cells; doesn't involve antibodies
undulate (margin)
uneven edges
irregular (form)
uneven shape from center to edges
lobate (margin)
uneven with deep indentations
immunodeficiency
unhealthy immune system characterized with a decreased or compromised immune response to pathogens; hyporeactive
flame
use fire to sterilize flasks GENERAL STEPS 1.) Put glove on hand and grasp flask firmly. 2.) Remove foil lid and sterilize lip of flask in flame. (Foil lid may be placed on table flask end up.) 3.) Open lid of Petri dish minimally and pour medium to cover bottom of plate and fill about ½ full. 4.) Close Petri dish lid immediately. 5.) Sterilize lip of flask in flame and recap with foil lid. 6.) Set plate out of way and allow to solidify. Immediately after medium is solid, invert plate. (This minimizes condensation in plate.)
Phototrophs
use light energy to promote photophosphorylation
simple stain
use of a single basic dye
deep freezing
used for long-term storage; maintaining temperatures between -50 C to -95 C (around -100 F)
deep-freezing
used for long-term storage; maintaining temperatures between -50 C to -95 C, which is colder than "frozen" method of preserving bacterial cultures
Amphotericin B Nystatin
used to form complexes with sterols on fungal membranes which causes leakage
streak plate method
used to isolate pure cultures
single stranded RNA (ssRNA)
used to produce (viral) DNA via reverse transcriptase (an enzyme that plays a key role in reverse transcription) •Viral DNA integrates into the host chromosome as a provirus EXAMPLES Retroviridae •Lentivirus (HIV) •Oncoviruses
differential staining
using specific stains to distinguish different types of cell; Gram staining, acid-fast staining; not useful for bacteria without cell walls Some stains must be applied in a specific order to result in a counterstain
Serovar
variation within a species
Mumps
virus that causes swelling
bacteriophages (phages)
viruses that infect bacteria (or archaea) bacteriophages usually possess the head and tail but NO spikes. •Range from 20 nm to 1000 nm in length REPLICATION 1.) Tail fibers of the virus attach to the host's cell wall proteins. 2.) Viral DNA is injected into the host cell. NOTE: Uncoating is not required. 3.) biosynthesis occurs in the cytoplasm. 4.) The infection occurs as lysogeny. 5.) The host cell lyses as new viruses are released.
animal viruses
viruses that infect eukaryotes (plant, animal, fungi, protozoa, human, etc.) Animal viruses usually only possess the head and its components-capsid and spikes- but no tail, or the components of the tail. REPLICATION 1.) The virus attaches to the host on plasma membrane proteins and glycoproteins 2.) The capsid enters the host by endocytosis or fusion. 3.) Uncoating occurs; the enzymatic removal of capsid proteins. These enzymes can either be the virus's or the host's. 4.) biosynthesis (eclipse) occurs; the production of viral nucleic acid and viral proteins > DNA virus: nucleus of the host > RNA virus: cytoplasm of the host 4.) Maturation: nucleic acid and capsid proteins assemble into the "new" viruses. > The infection occurs as latency. (slow viral infections; cancer) 6.) RELEASE: depends on the type of virus; Enveloped viruses bud out; nonenveloped viruses rupture plasma membrane. •Release by budding (enveloped viruses) or rupture (non-enveloped viruses)
visible light
visible electromagnetic waves of light Visible light is detected as colors by the human eye. Shorter wavelengths possess greater energy.
incineration
waste treatment process that involves the combustion of organic substances contained in waste materials. The high-temperature burning of solid waste usually converts the reactants into ashes, flue gas, and heat.
Flagella
whiplike tails found in one-celled organisms to aid in movement long projections; few in number consists of microtubules made of the protein tubulin
Flagella
whiplike tails found in one-celled organisms to aid in movement •Filamentous appendages external of the cell •Made of protein: flagellin Three parts •Filament: outermost region •Hook: attaches to the filament •Basal body: consists of rod and pairs of rings; anchors flagellum to the cell wall and membrane Flagella allows bacteria to move toward or away from stimuli (taxis) •Flagella rotate to "run" or "tumble" •Flagella proteins, H antigens, are useful to distinguish among serovars (EXAMPLE: Escherichia coli O157:H7)
Leukocytes
white blood cells (WBC) possess a nucleus but no hemoglobin, responsible for fighting infection
plasma cells (plasma B cells)
white blood cells that originate in the bone marrow and secrete large quantities of proteins called antibodies in response to being presented specific substances called antigens. These antibodies are transported from the plasma cells by the blood plasma and the lymphatic system to the site of the target antigen (foreign substance), where they initiate its neutralization or destruction. B cells differentiate into plasma cells that produce antibody molecules closely modeled after the receptors of the precursor B cell.
vasodilation
widening of blood vessels
asymptomatic
without symptoms
Triple X Syndrome
xxx
Mediators
• Histamine: increases the permeability of blood capillaries • Leukotrienes: cause prolonged contraction of smooth muscles • Prostaglandins: affects smooth muscle and increases mucus secretion
Robert Murray
•1968 Kingdom Prokaryotae is proposed
Whittaker
•1969 a five-kingdom system is introduced prokaryotes were placed in the Kingdom Prokaryotae or Monera; eukaryotes comprised the other four kingdoms: -Fungi -Plantae -Protista -Animalia The Kingdom Prokaryotae was based on microscopic observations.
cell wall
•Found in plants, algae, and fungi •Made of carbohydrates (cellulose—plants, chitin—fungi, glucan and mannan—yeasts)
Prokaryote Anatomy
•One circular chromosome which isn't bound in a membrane •No histones •No organelles •Divides by binary fission Bacteria •peptidoglycan cell walls Archaea •pseudomurein cell walls
eukaryote anatomy
•Paired chromosomes which are bound in a nuclear membrane •Histones •membrane-bound Organelles •Some eukayotes possess polysaccharide cell walls. •Divides by mitosis
Prokaryotic cell division
•Reproduces via *binary fission*; the chromosome is duplicated into two exact copies. One copy moves toward the opposite end of the cell. -possession of a single, circular chromosome -quick and efficient with few mutations, but reduces amount of genetic variation The cell elongates as the duplication is occurring. When the duplication is complete, creating two copies on opposite sides, the plasma membrane begins to pinch inward. This physically divides the original cell into two new cells.
portals of exit
•Respiratory tract (Coughing and sneezing) •Gastrointestinal tract (Feces and saliva) •Genitourinary tract (Urine; other secretions from the penis and vagina) •Skin •Blood (Arthropods that bite; needles or syringes)
Lysosomes
•Vesicles formed in the Golgi complex •Contain digestive enzymes -contains hydrolytic enzymes used to digest macromolecules -Phagocytosis: engulfing smaller organisms or food particles (Used primarily by Amoebas, protists, macrophages) -Some types of cell can engulf another cell by phagocytosis; this forms a food vacuole
Bacteriophage plaque
•Viruses must be grown in living cells •Bacteriophages are grown in bacteria •Bacteriophages form plaques, which are substances on a lawn of bacteria. The lawn of bacteria is grown on the surface of agar •Each plaque corresponds to a single virus; can be expressed as plaque-forming units (PFU)
Prokaryote
•introduced in 1937 to distinguish cells without a nucleus
DNA virus
•replicate their DNA in the nucleus of the host using viral enzymes •Synthesizes the capsid in the cytoplasm using host cell enzymes (REFER TO THE DIAGRAM)