Microbiology Exam 2.3xxx
peroxide anion
(O2 2-) Is produced when free radicals react with hydrogen ions. *toxic to cells. **This is hydrogen peroxide can be used as a antimicrobial agent.
lag phase
"flat" period of adjustment, enlargement; little growth
Match the chemical mutagens with their descriptions.
1- Intercalating agents: insert between base pairs 2- Base analogs: used in place of normal nucleobases 3- Alkylating agents: add CH3 and others to nucleobases 4- Transposons: randomly insert into DNA
what are the four bacteria in the enteric bacteria class?
1. E coli 2. shigella 3. enterobacter 4. salmonella
what are the five steps of phagocytosis by macrophages?
1. attachment: attaches to pseudopodia 2. ingestion: forms phagosome to move towards lysosome 3. fusion of lysosome and phagosome: releases lysosomal enzymes into phagosome 4. digestion 5. release of products from the cell
what are the four antibacterial targets?
1. cell wall synthesis 2. nucleic acid precursor synthesis 3. protein biosynthesis 4. DNA/RNA synthesis
what are benefits of fungi?
1. food (blue cheese, soy sauce, tea, beer) 2. medicine (antibiotics- penicillin) 3. biocontrol (insect pests of crops) 4. recycling 5. plant growth (symbiotic)-Mychorrizhal association
what are the steps of antigen presentation for MHC Class I?
1. intracellular microbe comes in 2. ubiquitin attaches to protein, making it for degradation 3. these degraded proteins are transported to the ER through transporters called TAP1 and TAP2 4. protein loaded onto MHC I complex 5. transported to cell surface to be recognized by CD8
how is listeria able to survive and replicate?
1. it can survive the stomach acidity 2. survives in macrophages
what are the steps of B cell activation?
1. macrophage acts as APC and forms the antigen MHC complex 2. Th ( CD4) cell recognizes the MHC Class II and binds 3. B cells differentiate into memory b cell or plasma cell (will secrete Ab)
what are prostaglandins and leukotrienes released from? what are its two actions?
1. mast cells 2. damaged cells what does it do? 1. increase vascular permeability 2. chemotaxis of neutrophils towards wound site
Production of Hybridomas
1. mouse is injected with antigen 2. plasma cells are removed from spleen 3. hybridomas formed by mixing and fusing with human myeloma cells- can live forever and produce antibodies 4. hybridomas are placed individually in small wells and tested for reactivity against the antigen 5. the hybridoma that reacts with the antigen is cloned see which one binds best to antigen monoclonal antibodies all the same, all bind to same antigen limitation: not available for everything
what can occur if a pregnant women is infected with listeria monocytogenes?
1. premature birth 2. spontaneous abortion 3. stillbirth
what factors promote growth in environmental conditions?
1. temperature 2. precipitation 3. humidity 3. enrichment of soil through bird and bat guano (feces)
FALSE
10) The human body is typically free of archaeal species.
B) actinomycetes and related organisms
13) Which of the following form conidiospores? A) endospore-forming gram-positive rods and cocci B) actinomycetes and related organisms C) rickettsias D) anaerobic gram-negative cocci E) spiral and curved bacteria
Facultative anaerobe
A bacterium in inoculated into a tube of thioglycollate and incubated. After incubation, turbidity appears throughout, top to bottom, with the greatest turbidity at the very top. The bacterium would be called a(n) _______.
Nonsense
A mutation that changes a normal codon to a stop codon is called a ______ mutation
True
A proteome is an organism's full array of expressed proteins, and proteomics is the study of those proteins and the functions they mediate.
Metallic ions
A type of cofactor would be
Enzyme
A type of protein that speeds up a chemical reaction in a living thing
35) In Figure 10.3, which two are most closely related? A) 1 and 3 B) 2 and 4 C) 3 and 5 D) 2 and 5 E) 4 and 5
A) 1 and 3
32) In Table 10.1, which features are found in nearly all eukarya? A) 2, 3, 5 B) 1, 4, 6 C) 3, 5 D) 2, 3 E) 1, 2, 5
A) 2, 3, 5
9) Which of the following is the best evidence for a three-domain system? A) Nucleotide sequences in ribosomal RNA vary between all three domains. B) There are three distinctly different sets of metabolic reactions. C) There are three distinctly different Gram reactions. D) Some bacteria live in extreme environments. E) There are three distinctly different types of nuclei.
A) Nucleotide sequences in ribosomal RNA vary between all three domains
30) A clone is A) genetically identical cells derived from a single cell. B) a genetically engineered cell. C) a taxon composed of species. D) a mound of cells on an agar medium. E) None of the answers is correct.
A) genetically identical cells derived from a single cell.
20) The arrangement of organisms into taxa A) shows degrees of relatedness between organisms. B) shows relationships to common ancestors. C) was designed by Charles Darwin. D) is arbitrary. E) is based on evolution.
A) shows degrees of relatedness between organisms.
helminth, fungi, bacteria, protozoa
Aerobic Respiration: Which organisms?
False
After three replication cycles in PCR, there will be a total of three double-stranded DNA molecules.
All of the choices are correct
Alcohols : (DENATURE PROTIENS WHEN IN A 50-95%ALCOHOL WATER SOLUTION, DISINFECT ITEMS WHEN SOAKING METHOD IS UTILIZED, ARE SKIN DEGERMING AGENTS, AT 50%OR HIGHER CONCENTRATIONS DISSOLVE CELL MEMBRANE LIPIDS)
attach to the 30S ribosomal subunit and disrupt protein synthesis.
Aminoglycosides
True
Aniline dyes like crystal violet have antimicrobial activity particularly against gram-positive bacteria and some fungi
Staphlycoccus
Antibiotics are derived from all of the following, except
histoplasmosis is classified as.....
Ascomycota
False
Bacteria like E. coli have an average generation time of 24 hours.
a donor cell with a plasmid that synthesizes a pilus.
Bacterial conjugation involves
2) Which of the following characterizes the Domain Bacteria? A) prokaryotic cells; ether linkages in phospholipids B) eukaryotic cells; ester linkages in phospholipids C) prokaryotic cells; ester linkages in phospholipids D) complex cellular structures E) multicellular
C) prokaryotic cells; ester linkages in phospholipids
which of the complement fragments is inflammatory
C3a, C4a, C5a
cystic fibrosis occurs when there is a mutation in which gene?
CFTR gene nonsense mutation (STOP codon) symptoms: lung infection due to chloride abnormality
Pure cultures are often obtained by isolating A) streaks. B) broths. C) CFUs (colony forming units). D) inoculums. E) specimens.
CFUs (colony forming units).
neutrophils
Can engulf bacteria Can generate extracellular fibers that bind to bacteria And then produce chemicals that kill that bacteria
malachite green helps identify which organism?
Clostridium difficile
Facultative anaerobe
Cultures of a bacterial strain were incubated in a standard incubator, in an anaerobic jar, and in a candle jar. After incubation, there was moderate growth of cultures in the candle and anaerobic jars, but heavy growth of the culture in the incubator. This species is a(n)
What is the often reason why people die from foodborne/fecal-oral diseases?
- not because of the symptoms but because of dehydration caused by the symptoms!
why is the micro biome important?
- regulate intestinal environment - control proliferation of pathogens - Affect metabolism - Regulate development of immune system - Protect against tissue damage in intestines - Even pathogens may have benefits: Helicobacter infected children have lower incidence of asthma
Gamma rays and X-rays
Electrons are ejected from atoms in cells when organisms are exposed to
the specificity is found where on the antibody molecule?
Fab (antigen binding fragment)- two arms of the Y forms a heavy chain and light chain
CARRIER PROTEINS IN THE MEMBRANE
Facilitated diffusion is limited by
closed system, nutrients are depleted, waste accumulates
Factors that promote the onset of the stationary and death phase
internal organic mol.
Fermentation: final e- acceptor
lactose present without glucose
Full induction of the lactose operon requires
isotonic
characteristics of a solution having the same concentration of solutes and water as another
cell membrane
In bacterial cells, the electron transport system is located in the
what culture contains antibiotic inhibitors to inhibit bacteria and saprobic molds?
Inhibitory Mold Agar (IMA)
False
Isopropyl alcohol wiped across a skin site can sterilize it
False
Lactose is a corepressor in the lac operon
CRISPR uses pieces of phage DNA incorporated into the genome
as the source of an RNA that will guide Cas proteins to cleave the foreign DNA.
GIARDIA INTESTINALIS —> Giardiasis
DISEASE: - giardiasis FEATURES - mastigophora "animal like" flagella that moves like a whip - forms cysts (dorman form that can survive in the water or soil) LIFECYCLE: - replicates in the intestines and form cysts
True
DNA polymerase can only add new nucleotides to the 3' DNA end of the template.
difference between DNA and RNA in transcription and translation
DNA: transcribe to mRNA then translated into proteins RNA: can bypass transcription during protein synthesis since they already contain RNA in genome
The synthesis of __________ from a(n) __________ template is an enzymatic activity of reverse transcriptase.
DNA; DNA RT can synthesize DNA from a DNA or an RNA template.
Mechanisms of resistance
Deactivate the drug- make it so drug cant do anything anymore Prevent entry of the drug Alter receptor for the drug Change metabolic pathway drug is targeting so you no longer have to use it Remove the drug from the cell- pump it out, one of the worst ones, genes bacteria can get that will create a drug pump that pumps thing back out of cell, makes them resistant to multiple drugs bc pumping them all back out Protect drug target- make it so that drug cant access target Living in a biofilm- not as accessible to drug, cant get through organic matter, ones on inside survive even if ones on outside die
what is the heavy chain and what is the light chain of the antibody molecule?
heavy chain: constant region light chain: variable region-Fab
binary fission
how does reproduction occur in bacteria
False
Drugs that are hepatotoxic cause damage to a patient's kidneys.
The majority of reduced NAD is produced in a. glycolysis b. Kreb's cycle c. electron transport chain d. photosynthesis e. none of the choices is correct
b. the Kreb's cycle
Mesophile
bacteria that prefers moderate temperature and develops best at temperatures between 25 C and 40 C
when pathogenic bacterial cells lose the ability to make adhesions, they typically
become avirulent
Enzymes that are always present, regardless of the amount of substrate, are a. apoenzymes b. axoenzymes c. constitutive enzymes d. regulated enzymes e. endoenzymes
c. constitutive enzymes
An apoenzyme is a. part of a simple enzyme b. also called a coenzyme c. the protein part of a holoenzyme d. often an inorganic metal ion e. an RNA molecule
c. the protein part of a holoenzyme
The rotation of the flagellar rotors
can switch between smooth swimming (counterclockwise) and tumbling to change direction (clockwise)
generalized transduction
can transfer any gene from a donor to a recipient cell
specialized transduction
can transfer only a few closely linked genes between cells
which disease presentation is asymptomatic in many people and can cause PID, swollen and tender testicles in men?
chlamydia
what is responsible for the diversity of immunoglobulins?
chromosomal rearrangement human can respond to 10^15 epitopes called the clonal selection theory by burnett
what is the mold and its hyphae called?
collectively called mycelium
2 component signal transduction pathway
collects information outside of cell relying on series of 2 member protein phosphorylation relay system and regulates different set of genes
parasites
common features: life cycle takes different forms, can be treated, no permanent damage in most cases
2 recognized types of epidemics
common source and propagated
Biofilms
community of bacteria attached to a surface and to one another surrounded by an extracellular matrix made of biological polymer
In addition to transformation, the other two forms of horizontal gene transfer are
conjugation and transduction
Catabolism
Metabolic pathways that break down molecules, releasing energy.
Anabolism
Metabolic pathways that construct molecules, requiring energy.
cyclic
Metabolic pathways that regenerate their starting molecule are called ________ pathways
superoxide radicals
O2- form during incomplete reduction of oxygen in aerobic and anaerobic respiration
Microarray Analysis
Of the following choices, which could be used in the treatment of a patient in order to determine the patient's cancer subtype?
Newer drugs that block translation work in other ways
Oxazolidinones [Linezolid (Zyvox)] - blocks initiation- used as last resort drug for treating highly resistant gram+ bacteria that are resistant to everything else Antiviral Fomivirsen (Vitravene)- blocks translation, antisense nucleic acid inhibits transcription and translation Treats cytomegalovirus eye infections
You set up a third test tube containing 8mL water, 1mL PTU, 1mL potato juice, and 3mL catechol. If this third test tube turned brown, this would suggest which of the following?
PTU is a competitive inhibitor of catechol oxidase
False
Photosynthesis occurs in chloroplasts of prokaryotes
Point mutations
SNP's are derived from
Degermation
Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is
cellular proteins
Structural genes code for
Hydrogen peroxide
The chemical agent/s that produce/s highly reactive hydroxyl-free radicals and also decomposes to O2 gas is ______.
faster
The closer the cell is to its optimum temperature the _____ it will grow
thermal death time is the shortest amount of time required to kill an organism at a specific temperature, whereas thermal death temperature is the lowest temperature required to kill an organism in 10 minutes.
The difference between thermal death time and thermal death point in microbicidal activity is that
anabolism
The formation of peptide bonds between amino acids to build a polypeptide is an example of
the genotype refers to all of the genetic material in the organism, whereas the phenotype represents only the genetic material that is expressed into proteins.
The fundamental difference between an organism's genotype and its phenotype is that
121°C at 15 psi for 15 minutes
The minimum sterilizing conditions in a steam autoclave are
Regulator
The operon segment composed of the gene that codes for a protein repressor is called the
replication fork
The site where the old DNA strands separate and new DNA strands will be synthesized is called the
Base Pairs
The size of DNA is often given in the number of _____ that it contains
what is a causative agent of syphillis?
Treponema pallidum helical shaped bacteria
Cyanide
What chemical causes death in many eukaryotes because it blocks cytochrome C oxidase?
cytoplasm
Where does glycolysis occur in prokaryotes?
cytoplasm
Where does synthesis of Acetyl CoA occur in prokaryotes?
Tincture of Iodine
Which of the following is not a heavy metal?
does listeria exhibit beta hemolysis when grown on blood agar plates?
YES
One sign of horizontal gene transfer is
a GC base ratio different from flanking chromosomal DNA. Each type of microorganism has particular GC ratios. Regions of the genome with highly different ratios may be examples of genes acquired via horizontal transfer
disinfectant
a chemical substance that kills harmful bacteria or viruses
contagious disease
a disease that is easily passed from host to host in aerosols
contagious disease
a disease that is easily spread from one host to another
communicable disease
a disease that is spread from one host to another
The F pilus is
a protein appendage that attaches the two cells together
A hydrogen atom consists of
a proton and an electron
biofilm
a slimy community of microbes growing on a surface
Exogenous nosocomial infection
acquired from the health care environment, a lot of pathogenic bacteria bc a lot of immune compromised people, breeding ground for resistance
In the absence of lactose, the lac repressor is
active and can bind to the operator
ethanol and CO2
alcoholic fermentation chemicals
wine and beer
alcoholic fermentation products
Which cells express MHC class I molecules in a patient?
all nucleated cells
differential media
allows growth of several types of microbes and displays visible differences among those microbes
which type of epidemiologists is most like a detective
analytical epidemiologist
Which viruses may enter cells via receptor-mediated endocytosis?
animal viruses
which protein do neutrophils release to recruit monocytes to the inflammed location?
azurocidin a potent chemoattractant
Each FADH2 from the Krebs cycle enters the electron transport system and gives rise to ____ ATPs a. 1 b. 2 c. 3 d. 4 e. 5
b. 2
In the cell, energy released by electrons is often used to phosphorylate a. ATP b. ADP c. pyretic acid d. oxygen e. NAD
b. ADP
Enzymes that are only produced when substrate is present are termed a. exoenzymes b. endoenzymes c. constitutive enzymes d. induced enzymes e. conjugated enzymes
d. induced enzymes
Each of the follow is true of enzymes except a. they can be used over and over b. they may or may not require cofactors c. their active site is specific to the substrate d. they increase the activation energy of a reaction e. all of the choices are true of enzymes
d. they increase the activation energy of a reaction
degradation of RNA
degradosome: RNase, an RNA helicase, and two metabolic enzymes
outline safety changes made to viruses to convert them into gene therapy vectors
deleting virulence genes avoiding genome insertion next to oncogenes altering tissue specificity avoiding germ line infection
how does lysozyme protect body?
destroys gram pos cell wall
Disinfection
destroys most organisms on a non-living surface
chronic disease
develop slowly (usually with less severe symptoms) and are continual or recurrent ex: infectious mononucleosis, hepatitis C, tuberculosis, leprosy
Blood agar plates are an example of ________ medium. A) differential B) selective C) reducing D) defined E) transport
differential
physical methods of microbial growth
dry heat, desiccation, filtration, low temperature, radiation, moist heat, osmotic pressure
Where do NADH and FADH2 go after being produced in the TCA Cycle?
electron transport chain
A patient contracted athlete's foot after long-term use of a medication. His physician explained that the malady was directly related to the medication. Such infections are termed
endogenous infections
and ELISA uses what reagents
enzyme-labeled anti- antibody
common source epidemic
epidemics involve contact with a single contamination source, see a lot of cases quickly, isolate source, cases go down really quickly ex: e coli in ground beef, botulism in pickles, air conditioning
How common is HPV?
everyone is technically infected 1 in 4 14 million new cases every year 150 different strains
T/F: A missense mutation has a greater impact on a cell than does a frameshift mutation.
false
T/F: A transposon always causes a mutation.
false
T/F: A. baumannii is easily removed from hospital surfaces by disinfectants.
false
T/F: After conjugation of an Hfr cell and a F- cell, the entire genome of the Hfr cell is usually transferred to the recipient cell.
false
T/F: All mutagens are carcinogens but not all carcinogens are mutagens
false
T/F: In anaerobic respiration, the terminal electron acceptor would also be oxygen.
false
T/F: The enzyme ethylguanine-DNA ethyltransferase prevents DNA mutations from occuring
false
T/F: The plus (+) strand of DNA acts as a template during
false
Streptococcus pneumoniae lacks an electron transport chain. Therefore, S. pneumoniae generates ATP via ________.
fermentation
In eukaryotic cells undergoing respiration, protons are pumped
from the mitochondrial matrix to the intermembrane space
F+ cells
have a plasmid and are donors in conjugation
average half life of sRNAs
highly variable
antibody production is part of which kind division of adaptive immunity?
humoral immunity
what are the multiceullar filaments of molds called?
hyphae they grow as branching threadlike filaments
what organ is fever regulated by?
hypothalamus
What causes decline stage in bacteria? (don't usually die because they've run out of food in host)
immune response or antibiotic can kill bacteria
in the regulation of the lac operon, lactose acts as a/an:
inducer
The lac operon is
inducible
what are the tuskegee experiments?
investigated what untreated syphilis would do to the human body conducted unethical studies on african american men infected with treponema pallidum
pandemic disease
it is an epidemic that occurs on more than one continent at the same time
In transduction, bacterial DNA is transferred to a new cell when
it is injected by the virus carrying bacterial DNA
Sterilization
kills all microorganisms
Aspergillus, Lactobacillus, Streptococcus
lactic acid fermentation bacteria
Dracunculus medenisis (guinea worm)
life cycle: on contact with water, worm bursts, releasing larvae into water - water fleas invest the larvae - person drinks the water with the water fleas, and lava are released in the stomach - larvae resists digestion and migrate to the small intestine, penetrate the intestinal wall into the body cavity , where they grow into worms and mate - fertilized female worms move through connective tissue, usually the lower limbs - around a year later, worm forms a blister near the skin surface, the blister bursts, exposing the worm
what is targeted by a toll like receptor
lipid A, single-stranded RNA, lipoteichoic acid (not eukaryotic flagellar protein)
which organism is a gram positive and facultative anaerobe that causes meningitis?
listeria monocytogenes
what does gamma hemolysis look like?
little to no hemolysis
what kind of molecule is an antigen?
macromolecule such as a protein or polysaccharide
which cells, without the assistance of antibodies, recognize and directly phagocytose many kinds of bacteria and can also act as a antigen presenting cell to t cells?
macrophages
what do monocytes in blood become?
macrophages ex: kuppffer cells in the liver
what are four important antigen presenting cells?
macrophages dendritic cells skin langerhan cells vascular endothelial cells
antibodies function to
mark invading organisms for destruction
who is typhoid mary?
marry mallon who spread salmonella asymptomatically 51 infected and 5 died quarantined until her death
which leukocyte is prevalent in CT and along blood vessels that also releases histamine associated with allergies?
mast cells
what three cell types release histamine? what are its three actions?
mast cells basophils platelets 1. causes capillary leakage 2. allows phagocytosis to occur 3. attracts platelets/clotting factors to the site
Viral genome integrated within host DNA
may be a permanent condition
what is any heritable change or alteration of DNA?
mutation
chemical, physical
mutations can arise from ____ or _____ agents
amensalism
one symbiont harmed by a second symbiont, second is neither harmed nor helped ex: fugue penicillium inhibits nearby bacteria, but bacteria have no effect on the fungus
Nitrogen is a growth-limiting nutrient for many organisms because A) it is necessary for the biosynthesis of amino acids. B) it is required for synthesis of nucleotides. C) it is required for lipid synthesis. D) only a small number of bacteria are able to extract it from the atmosphere. E) only a few microbes can extract it from the atmosphere, but all organisms require it for amino acid and nucleotide synthesis.
only a few microbes can extract it from the atmosphere, but all organisms require it for amino acid and nucleotide synthesis.
photoautotroph
organism that requires light energy and uses carbon dioxide as a carbon source; example-plant
Cells obtain energy by _______ food molecules such as glucose.
oxidizing
What functional group do kinases transfer to other molecules as signals of environmental change?
phosphate
post translational modification: chemical modifications
phosphorylation, methylation, or glycosylation) of individual amino acids.
what does fusidic acid do?
prevents translocation
Viroids lack
proteins. Viroids are naked nucleic acids, usually RNA, devoid of a protein capsid. Some plant viroids are ribozymes, capable of catalytic action.
post translational modification: proteolytic processing
proteolytic processing of an inactive polypeptide to release an active protein component
The enzyme ATP synthase uses energy from _____ to make ATP.
protons re-entering the cell
When a stop codon is in the A site,
release factors bind to the A site and activate peptidyltransferase, freeing the newly synthesized protein from the tRNA in the P site. A number of other factors are then required for ribosome subunit separation
evaluate the evidence for horizontal gene transfer by phylogenetic approaches
rely on the differences between genes and species tree evolution that result from HGT
Degerming
removal of microbes by mechanical means
post-translational modification include
removal of translate signal sequences proper folding of polypeptide proteolytic processing chemical modifications
Degerming
removing microbes from a limited area
eosinophils
secrete toxins that weaken or kill helminths eosinophilia is indicative of a helminth infection have help from adaptive when body is responding to threat from worm, you will produce IGE (antibody subtype) specific to bind to that worm, that IGE will bind to eosinophils and the eosinophils will bind to worm as a result, eosinophils bind to constant portion of the antibodies, allows them to know where the worm is and dump their toxic granules on the side where the worm is so that they are poisoning the worm
the study of antibody-antigen interaction in the blood is
serology
structure and function of capsid
structure: can be symmetrical or asymmetrical function:packages viral genome and deliver it into host cell
in a Kirby-bauer susceptibility test, the presence of a zone of inhibition around disks containing antimicrobial agents indicates
that the microbe does not grow in the presence of the agents
when have mycoses been more prevalent?
the past 50 years has high mortality due to increased number of IC patients
disinfection
the use of physical or chemical agents to inhibit or destroy microorganisms on *inanimate objects*
most plants are naturally resistant to viral infection by direct contact due to
their robust cell wall
how does the body recognize the microorganism that just invaded?
through the innate immune system by pattern recognition receptors called TLRs TLRs found on: - cell surface (LPS, peptidoglycan) -on host cell endosomes
virulence factors
traits that interact with host and enable pathogen to enter host, adhere to host cells, gain access to nutrients, evade immune system ex: adhesion factors, biofilm formation, extracellular enzymes, toxins, antiphagocytic factors
T or F: Lymphocytes are a type of leukocyte
true
Which of the following is an indirect method for estimating the number of microbes in a sample? A) viable plate counts B) turbidity C) Coulter counter D) MPN E) membrane filtration
turbidity
lentivector
used to integrate genomes into neurons (non-dividing cells) which are hard to infect They do not tend to trigger an immune response, and integration means the subject is permanently transfected. longer lasting therapy acts at "taxi" to shuttle in CRISPR
transcriptional attentuation
uses ribosome as sensor of aa levels and determines whether transcribing RNA polymerase can continue transcription via loops
compare stages of infectious disease to the stages or a bacterial growth curve
very similar Stages of infectious disease incubation period- no signs or symptoms prodromal period- vague, general symptoms illness- most severe signs and symptoms decline- declining signs and symptoms- immune system or antibiotic kills convalescence- no signs or symptoms- no parallel with bacterial Stages of bacterial growth curve: lag phase- similar to incubation period log (exponential) phase- similar to prodromal Stationary phase Death (decline) phase- similar to decline- nutrients used up, toxic by products
RNA retroviruses use
viral reverse transcriptase to make a DNA copy that is integrated into the host genome and then host RNA polymerase transcribes it.
3 forms a virus can assume
virion, intracellular replication compLex, viral genome integrated within host DAN
therapeutic use of engineers herpes simplex virus
virotherapy: engineered to remove virulence and fights cancer oncolytic NOT oncogenic
etiological agents
viruses, parasites, bacteria
regulated expression
when things are present in media for growth dependent on environment and can be turned on or off
Why would it be beneficial for cells to wait until a critical population density is reached before expressing certain genes?
without a certain density, it would be highly unlikely that the molecules produced by a cell in the group could find and bind to other cells of the population effectively.
active immunity- memory
works same way with natural infections specific to antigen exposed to
Saccharomyces cerevisiae (yeast)
alcoholic fermentation bacteria
False
An antimicrobial with a low therapeutic index is a safer choice compared to a drug with a high therapeutic index.
inhibits DNA synthesis
An antiviral that is guanine analog would have an antiviral mode of action that
Photoheterotrophs
Energy from sunlight, carbon from organic compounds
After entry of the bacteriophage into the host cell, a phage enzyme
breaks the host DNA into fragments
which spectrum targets against gram positive and also some gram negative organisms?
broad spectrum agents
False
All microbicidal agents are sterilants.
12) The phylogenetic classification of bacteria is based on A) cell morphology. B) Gram reaction. C) rRNA sequences. D) habitat. E) diseases.
C) rRNA sequences
15) Fossil evidence indicates that prokaryotic cells first existed on the Earth A) 350 years ago. B) 3500 years ago. C) 35000 years ago. D) 3.5 billion years ago. E) 3.5 × 1012 years ago.
D) 3.5 billion years ago
BALANTIDIUM COLI
DISEASE: balantidiasis or diarrhea FEATURE: ciliaphora (movement with cilia)
True
Excised introns form structures called lariats.
What are the 5 isotypes of antibodies?
GAMED IgG IgA IgM IgE IgD
nosocomial infections
Infections acquired while in a health care facility Huge problem Types- exogenous and endogenous
determine which genes are being expressed in an organism.
Microarray analysis is used to
viriods are
RNA molecules that infect plants.
transformasomes
Specific protein complexes required for natural transformation
the Krebs cycle
The majority of NADH is produced in
False
The majority of microbes live and grow in habitats between pH 7 and 9.
Antisepsis
The method of removing vegetative life forms from living surfaces is termed
False
Viruses are often used as cloning hosts in recombinant DNA methods.
SURFACE STRUCTURES FOR ATTACHING TO TISSUE
Which of the following properties is likely to be found in a pioneer colonizer of a biofilm on an artificial joint implant?
Most antimicrobial drugs are..
antibacterial
Conjugation
conjugation pili and F plasmid
axenic environment
contains only one species
how do defensins protect the body?
create pores in bacteria killing it
Eventually Eduard Buchner showed that crushed (destroyed) yeast cells could convert sugar to ethanol and CO2. What did this experiment show?
something was released from the crushed cells that could still convert sugar to alchol
The F plasmid encodes for
the F pilus
In aerobic respiration, oxygen acts as
the terminal electron acceptor
The prokaryotic ribosome consists of
three RNAs and many proteins
traits that render bacteria pathogenic are referred to as...
virulence factors
endotoxins
(lipid A) is the lipid portion of the Gram-negative's outer layer of lipopolysaccharide can be released when gram-neg bacteria divide, die naturally, or are digested by phagocytic cells stimulate body to release chemicals that can cause fever, inflammation, diarrhea, hemorrhaging, shock, and blood coagulation
ADVANTAGE OF HAVING HUMAN AS THE ONLY RESERVOIR
- Unlikely to cause outbreak - Can be eradicated!
GASTROINTESTINAL TRACT
- an important organ - has a vast microbial community - many microbes are COMMENSAL - relatively small number of microbes cause human diseases, sometimes severe or fatal - some diseases can be treated - some diseases can be prevented - hygiene - clean environment - vaccines - eradication possible when human is the only host
How can H.pylori be diagnosed?
- can be detected and treated - non is fool-proof -> blood test for antibodies -> urea breath test -> biopsy combined with urease test and histological exam
After the completion of DNA replication in prokaryotic cells,
-each daughter cell contains DNA with one newly synthesized DNA strand and one original parental strand -both daughter cells have identical copies of DNA
Please select the statements that are true of inducible operons to test your understanding of the differences between inducible and repressible operons. Check all that apply.
-often contain genes for enzymes that function in catabolic processes -will be "turned on" in the presence of the substrate and "turned off" in its absence -the lac operon is an example
Distinguish between genotype and phenotype.
-phenotype: the organism's observable characteristics. For example, presence of a flagellum -genotype: the genetic makeup of the organism-- in other words, the DNA sequence
Match the types of RNA with their function.
-rRNA: present in ribosomes -tRNA: carries amino acids. to the growing peptide chain during translation -mRNA: contains the genetic information decoded during translation
RNA polymerases
-synthesize molecules shorter than the chromosome -use DNA as a template to synthesize RNA -synthesize chains of nucleotides
ANATOMY REVIEW
1. Mouth 2. Stomach 3. Small intestine —> duodenum, jejunum, ileum 4. Large intestine —> transverse colon, ascending colon, descending colon, sigmoid colon 5. Normal microflora
how do neutrophils get to the location of inflammation?
1. become stick due to selectins and weakly bind to the tissue 2. use integrins to strongly bind to endothelial tissue 3. exit the bloodstream guided by chemoattractants-at this point, stickiness is upregulated
what are some symptoms of rheumatic fever?
1. cardiac muscle scarring
Which of the following statements about translation are correct. Check all that apply.
-a codon can code for "punctuation"--for example, where translation should start or stop -two different codons can code for the same amino acid -a codon is found on mRNA while an anticodon is found in the tRNA
For each glucose molecule that enters glycolysis, how many times does the TCA Cycle "turn"?
2
Arrange the following proteins in the correct order in which they participate in DNA replication. 1=primase 2=helicase 3=DNA ligase 4=DNA polymerase
2,1,4,3
Amino-acyl-tRNA synthetases charge tRNAs with their respective amino acids. There are ________ amino-acyl-tRNA synthetases in a given cell
20, there is one amino-acyl-tRNA synthetases per tRNA
D) rRNA sequences
27) Which of the following is the best reason to classify Streptococcus in the Lactobacillales? A) Gram reaction B) morphology C) fermentation of lactose D) rRNA sequences E) found in dairy products
D) is a strict aerobe.
28) Streptomyces differs from Actinomyces because Streptomyces A) is an archaea. B) produces conidia. C) forms filaments. D) is a strict aerobe. E) is a bacterium.
2 techniques to obtain proteomic data
2D gel electrophoresis and mass spectrometry
How many molecules of NADH are generated for each turn of the TCA Cycle?
3
formed elements (things you can see) in blood
3 types: erythrocytes- red blood cells platelets- involved in blood clotting leukocytes- white blood cells, involved in defending the body against invaders two groups- based on what they look like under microscope granulocytes granulocytes
Consider the figure. If methylguanine replaces guanine in a DNa strand with the sequence 5'CGA3', the resulting change in the complementary strand after DNA replication would be
3'GTT5'
FALSE
3) Myxobacteria are classified as actinobacteria due to fungal-like lifestyle.
E) lack cell walls.
3) The characteristic most notable regarding the mycoplasmas is that they A) are aerotolerant. B) carry out fermentative metabolism. C) produce endospores. D) are nonpathogenic. E) lack cell walls.
bacterial and arachea organisms have been on earth for how many years?
3.8 BIllion years
C) endospore stain
31) You have isolated a gram-positive rod. What should you do next? A) Gram stain B) lactose fermentation C) endospore stain D) flagella stain E) enterotube
D) Staphylococcus
38) Which one of the following does NOT belong with the others? A) Bartonella B) Ehrlichia C) Rickettsia D) Staphylococcus E) Wolbachia
C) have stalks.
39) Caulobacter are different from most bacteria in that they A) are gram-negative. B) are gram-positive. C) have stalks. D) lack cell walls. E) are motile.
what are the four classes of fungi
1. chytridiomycota 2. zygomycota 3. basidiomycota: mushrooms 4 ascomycota (75% of all known fungi)-histoplasma "mycota"
what are three functions of the lymphatic system?
1. collect excess fluid 2. transport digested fat to CV system 3. provides innate and adaptive defect mechanisms against infection
what are three examples of powerful anti rejection medications?
1. corticosteroids: blocks inflammation 2. cyclosporine A: blocks T cell activity 3. Monoclonal antibodies: block t cell activity
what are the four steps of bacterial transduction?
1. donor is infected with phage 2. cell lysis 3. injection of donor DNA into recipient cell 4. recipient transductant with donor DNA
what four things occur during the process of inflammation?
1. release of chemotactic factors 2. increased blood flow 3. increased capillary permeability 4. loss of function result: (control, damage, adaptive response) 1. acute resolution 2. persistence of response leading to fibrosis or organ failure
what are examples of first line of defense?
1. skin (most difficult to penetrate due to sweat, fatty acids, and normal bacteria flora) 2. stomach acid 3. flushing of urinary tract 4. mucus production 5. cilia
D) Haemophilus.
16) Requirements for X and V factors are used to identify A) Staphylococcus. B) Escherichia. C) Neisseria. D) Haemophilus. E) Pseudomonas.
drugs for the treatment of infections have been used for how long?
17th century
Herpes simplex virus
Acyclovir is used to treat infections caused by
FALSE
4) The Gram stain is not suitable for identifying members of the Archaea.
how high is mortality rate in bone marrow transplant patients infected with aspergillum species?
90%
what temperature classify a fever?
>100 F normal: 98.6 F
Gene
A ____ is a specific segment of DNA that codes for the production of one functional product.
gel electrophoresis
A technique that separates a readable pattern of DNA fragments is ______.
Fertility plasmids (F factors)
Allow bacteria to mate with each other, carry instructions for conjugation
Antimicrobials mode of actions
Alterations of cell walls and membranes, Damage to proteins and nucleic acids
what is the center of the complement pathway? what activates this protein?
C3 activated by: C3 convertase
Types of Epidemiology
Descriptive Analytical Experimental
control of nosocomial infections
Disinfection with strong disinfectant Good housekeeping/hygiene Surgical asepsis Isolation of contagious/immunocompromised Hand washing Creation of infection control committee- rate going down some bc of these
True
E. coli is the best host for cloning because it possesses the mechanisms for processing and modifying proteins.
by binding to the ribosome, preventing translocation due to interference with the attachment of mRNA.
Erythromcycin, a macrolide, inhibits protein synthesis
BY BINDING TO THE RIBOSOME, PREVENTING TRANSLOCATION DUE TO INTERFERENCE WITH THE ATTACHMENT OF THE MRNA
Erythromycin, a macrolide, inhibits protein synthesis
which Ab serotype is the main one in the initial primary immune response and allows good complement activation
IgM
otitis media
Inflammation of the middle ear, often caused by the bacteria /Streptococcus pneumoniae/; often associated with biofilms
endocarditis
Potentially fatal inflammation of the endocardium: typically caused by a streptococcal bacterial infection; frequently associated with biofilms
Refridgeration
Preservation of food, non sterile 0-7oC
denaturation
Pure ethanol is less effective than aqueous solutions because ________ requires H2O
Antisepsis
Removing pathogens from living tissue
Rotavirus Is in the ____________ family dsRNA, Segmented (11 segments), Naked, Icosahedral Because it is __________ it can reassert its genome
Reovirus segmented
Adenine-thymine
Replication of DNA begins at a/an _______ rich area.
True
Restriction endonucleases are obtained from various species of bacteria.
True
Reverse transcriptase is used to make cDNA from an RNA template
AN ORIGINAL PARENT DNA STRAND AND ONE NEWLY SYNTHESIZED DNA STRAND COMPRISING A NEW DNA MOLECULE.
Semiconservative replication refers to
an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.
Semiconservative replication refers to
complement system
Series of proteins that undergo a cascade of being cleaved then stick to the surface of the bacteria and can cause things like opsinization- make microbe get phagocytosed easier, trigger inflammation, can poke hole in bacterial cell so its guts fall out Set of serum proteins that lyse foreign cells Complement can be activated in several ways Classical pathway- involves antibodies Alternate pathway Lectin pathway Alternate and lectin can just occur as part of innate immune system
specificity of phagocytes
Some have receptors for bacterial surface components Toll-like receptors (TLRs)- bind to a variety of things on surface of bacteria, might recognize Lipid A, flagellum, other cell wall components, double stranded RNA, then phagocytose Have microbe get coated with opsonins, provides a signal to phagocyte that it ought to engulf this thing Complement proteins act as opsonins Antibodies act as opsonins
what is found on the surface of all nucleated cells?
MHC Class I
what is an important factor in transplant rejection?
MHC formation
which bacteria is a gram negative diplococci that grows slowly and ferments only glucose, and causes STD/STIs?
Neisseria gonorrhoeae
True
Pasteurization does not inactivate endospores or thermoduric microbes
block peptidases that cross-link glycan molecules.
Penicillins and cephalosporins
Change shape of 30s ribosome
Streptomycin in class of aminoglycosides- change shape of 30s ribosome and so mRNA gets misread and proteins don't get made properly, will inhibit growth or kill cell Tend to be broad spectrum antibiotics bc all of prokaryotic cells have 30s ribosome
are metabolic analogs of PABA and block folic acid synthesis.
Sulfonamides
folic acid
Sulfonamides are metabolic analogs of PABA and block ________ synthesis
the ability to exist in a wide range of conditions.
The term facultative refers to
endosymbiosis theory
The theory that the eukaryotic cell evolved via the engulfing of one prokaryotic cell by another.
triplet
The three-base sequence on DNA that codes for an amino acid is called a
is inactivated by
The lactose repressor __________________ binding lactose
monoclonal antibodies
are produced by hybridomas, are secreted by clone cells, and can be used for passive immunization
what do the granules of neutrophils contain?
bactericial enzymes for internal digestion of bacteria
role of Cro protein in molecular regulation of the switch from lysogenic to lytic growth in viruses
blocks CI repressor which blocks expression of all other genes then lysis
nonionizing radiation
UV light, Disinfection and sterilization of surfaces and of transparent fluids and gases
sewage
UV radiation, drinking water uses filtration, halogens, and oxidizing agents, and septic tanks are all methods of control to treat _____
Group IV: (+) sense single stranded RNA viruses
Use positive sense + strand (coding) to make mRNA = viral proteins For replication: Make template strand via RNA dependent RNA polymerase
Evaluating efficacy of antimicrobials
Use-dilution test, Kelsey-Sykes Capacity test, In-Use test
True
Whether an organism is a photograph or a chemograph depends on its source of energy.
Heat target DNA to 94° C.
Which PCR step causes the denaturation of double-stranded DNA?
A protozoan in a fresh water lake, a bacterium in a fresh water lake, a bacterium in great salt lake (all of the above have problems in maintaining and fluid balance within the cell)
Which organism has a challenge to maintain cellular electrolyte and fluid balance in its environment?
Tropism can be defined as the
ability to infect a particular type of cell within the host.
tropism
ability to infect particular tissue type within host
Plasmids are
able to replicate independently of the chromosome
pH
acidophile alkalinophile neutrophile
infection with HIV causes
acquired immundefiency syndrome
slippage
adds/ deletes repeat from gene and alters translational reading frame in which can turn genes on or off
improving inactivated vaccines
administration in high or multiple doses may produce allergic reactions still much safer than live incorporation of an adjuvant adjuvants are substances that increase the antigenicity or the vaccine- increase immune systems ability to respond to antigens present may also stimulate local inflammation
Sporicide
an agent capable of destroying bacterial endospores
systemic infection
an infection throughout the body
Resistance plasmids (R plasmids)
carry genes that give resistance to one or more antimicrobial drugs
What does Erthromycin do?
causes abortive translocation
RNA stability is measured in terms of
half life
transformation
one bacterial cell dyes, lysis, and the bacteria next to it sucks up the leftover chromosomes
How often do you need a Tdap vaccine?
one dose at age 11 or 12, one dose with every pregnancy, at least one booster shot as an adult
Hydrogen consists of
one proton and one electron
Local infection
only a specific portion of the body is infected
Subunit vaccines
only part of the virus or bacterium is included fewer side effects than killed vaccine especially for bacterium- release toxins isolate just certain protein needed ex: pertussis
SOS repair
operate only when damage is so severe that the cell has no other choice but to die allows cell to tolerate mutations
Viruses that are effective gene therapy vectors should
have virulence genes removed.
Filamentous viruses
helical symmetry
accessory proteins in viruses
help with early viral infection via initiating transcription of genes Rna processing enzymes: modify mRNA
osmotic pressure
high salt or sugar, preservation of food, non sterile
the major inflammatory mediator released by degranulating mast cells in type 1 hypersensitivity is
histamine
what contributes to genome restructuring
horizontal gene transfers and duplications followed by functional divergence through mutation
why are sulfonamides effective
humans and microbes use PABA differently in their metabolism
Chemoheterotrophs
humans and pathogens are both
A microorganism found living under conditions of high ________ is a barophile. A) pH values B) oxygen concentrations C) hydrostatic pressure D) carbon dioxide levels E) salt concentrations
hydrostatic pressure
selection of an antimicrobial agent
ideal antimicrobial agent is stable during storage and fast acting ideal microbial agents do not exist
To obtain immediate immunity against tetanus, a patient should receive
immunoglobulin against tetanus toxin (antitoxin)
Obligate anaerobes may be cultured in the laboratory A) in a reducing medium. B) in a standard incubator. C) in standard Petri plates. D) on blood agar plates. E) in standard complex media.
in a reducing medium.
Plasmid DNA is transferred
in single-stranded form
slow release replication differs
in that phage particles reproduce without destroying the host cell in which grows slowly but doesn't die via filamentous phages
How can scientists verify claims that a product is effective when used in 50% water solution
in-use test
what kind of vaccine is flu virus
inactive vaccine
direct contact transmission
including person-to-person spread, typically involves body contact between hosts Ex: HIV through sexual intercourse
What does streptomycin do?
inhibits 70S ribosome formation
Bacteriostatic
inhibits growth of bacteria
how can sigma factors be regulated: anti sigma factor
inhibits sigma factor activity by targeting specific sigma factor and blocks access to core RNA polymerase and prevents expression until needed
primary infection
initial infection within a given patient
which part of the immune system are natural killer cells?
innate immune system
which is the difference between innate and adaptive immunity?
innate: nonspecific adaptive: specific
nonreplicative transposition
insertion sequence excises itself out of 1 host DNA while integrating into destination DNA
Hfr refers to a cell that has
integrated the F plasmid into its genome
death phase
interval in which # of dying cells exceeds # of new cells formed; so there is a decline in overall # of cells
which anti fungal agent is a ergosterol synthesis inhibitor?
intraconazole inhibits cell wall synthesis a class called azol antifungals
70%
is alcohol more effective at 70% or 100%
What happens to carbon dioxide after it is released during reactions of the TCA Cycle?
it diffuses out of the cell
A disease in which a pathogen remains inactive for a long period of time before becoming active is termed
latent disease
Enveloped viruses, most gram positive bacteria, nonenveloped viruses, fungi, most gram negative bacteria, active-stage protozoa, cysts of protozoa, mycobacteria, bacterial endospores
least susceptible to most susceptible to antimicrobial agents
During which growth phase are bacteria more susceptible to antimicrobial drugs? A) lag phase B) log phase C) stationary phase D) death phase E) The susceptibility is the same for all phases.
log phase
The growth of bacterial cultures is best described as A) arithmetic growth. B) lag growth. C) logarithmic growth. D) cell division. E) replication.
logarithmic growth.
whats the 1 degree (primary) response after an antigen stimulates the immune system?
low production of IgM and IgG (more IgM) takes 5-10 days happens after first time exposure to antigen
the shortest life of mRNA
mRNA: short lived - 1-3 min catalytic RNA: 3-5 minutes
entry receptor protein needs for attachment oh phage lambda in E.coli
maltose porin
what is a common site of action of anti fungal drugs?
membrane with ergosterol
hyperthermophile
microorganism requiring temperatures ranging from approximately 65 degrees Celsius to 105 degrees Celsius
obligate anaerobe
microorganism that cannot tolerate oxygen
obligate aerobe
microorganism that requires oxygen for growth
which type of mutation changes a polypeptide to an inactive or nonfunctional protein?
missense mutation why? it changes the code of the amino acid sequence
acetic acid (MR test) (vinegar)
mixed acid fermentation products
Population size
more bacteria, virus, or protozoa you start out with, harder to kill it all off Decimal reduction time- antimicrobials reduce number of microbes by certain amount for every bit of time they are exposed
Transposons
more complex than simple insertion elections bc carry other genes in addition to those required for transposition
animal was infected with a virus. a mosquito bit the animal, was contaminated with the virus, and proceeded to bite and infect a person. which was vector?
mosquito
vaccine type commonly given with an adjuvant
chemically killed vaccine
Consider the growth of L. methylaminiphilus on methylamine. How would you classify this species based on its metabolism?
chemoorganoheterotroph
A ________ is used in industrial microbiology to produce microbial products that are only synthesized during log phase growth. A) Coulter counter B) broth culture C) spectrophotometer D) pour plate E) chemostat
chemostat
what category of drugs encompasses antibiotics, antimicrobials, and drugs used in the treatment of cancer?
chemotherapeutics
An organism that requires chemical nutrients which serve as final electron acceptors is a(n) A) chemotroph. B) phototroph. C) lithotroph. D) autotroph. E) aerobe.
chemotroph
which is a source of genetic information?
chromosome
what must occur for proper bacterial division?
chromosomes must divide when the cell divides
plaque
clear area surrounding host cells from single progenitor lyse Each arises from single infected bacterium that bursts and phage parts diffuse to infect neighboring cells
Ascaris lumbricoides
clinical features: largest intestinal round worm, worldwide spread incubation period: weeks symptoms: abdominal pain, vomiting treatment: chemotherapy (mebendazole, albendazole, or pyrantel pamoate) no permanent damage
The proteome refers to the
complement of proteins present at a particular point in time.
which is a set of more than 20 large regulatory proteins made by the liver that plays a key role in host defense as a part of the innate immune response?
complement system 1 increase phagocytosis 2. lyse microrganisms (gram neg bacteria) 3. generate peptide fragments that regulate inflammation 4. produce chemokine to attract WBCs
Horizontal gene transfer can occur via
conjugation
which type of mutation inserts a stop codon and results in a dramatic change in phenotype?
nonsense mutation STOP codon
cystic fibrosis is an example of what type of point mutation?
nonsense mutation premature stop codon is added mutation of CFTR gene
Which of the following pairs is NOT correctly matched?
nonsense mutation--incorrect amino acid
inhibit peptide-transferase reaction
normally peptidyltransferase results in 2 amino acids being linked by peptide bond, chloramphenicol is an example of an antiobiotic that binds such that you can not get formation of peptide bonds and so no protein production Broad spectrum but not used very often bc it can cause adverse side effects in small number of people, fatal side effects
selective media
culturing media containing substances that either favor or inhibit the growth of microorganisms
differential media
culturing media formulated such that either the presence of visible changes in the media or difference in the appearance of colonies help microbiologist differentiate the kinds of bacteria growing
Which of the following contain a metal ion that can accept and donate electrons?
cytochromes
key molecules that control cell-mediated cytotoxicity
cytokines
which molecules help activate Cd4 and Cd8 cells?
cytokines perforins granzymes
transmission
direct contact: family, caretakers, food handlers contaminated water: drinking water, swimming pools, small lakes contaminated food
good test to detect rabies virus in brain of dog
direct fluorescent antibody
noncommunicable disease
disease not passed from person to person
structure of DnaK
do not form rings but can clamp down on peptide to assist
interferons..
do not protect the cell that secretes them. stimulate the activity of macrophages. cause muscle aches, chills, and fever.
alternative pathway
does not require antibodies, ONLY THE PATHOGEN SURFACE Activates C5b-C9 leads to formation of membrane attack complex and lysis of certain pathogens
Gluconeogenesis is the anabolic process by which microorganisms create monosaccharides for biosynthesis. Which of the following is NOT required for the gluconeogenic pathway? a. pyruvate b. NADH/NADPH c. CO2 d. ATP e. all of these are required for the synthesis of glucose
e. all of these are required for the synthesis of glucose
Oral
easy to take, people more willing than shot, lower concentration of drug in body, drug has to be able to withstand stomach acid, has to be one that you can absorb
age of chemical
efficacy usually declines over time
Organisms that can grow with or without oxygen present are A) obligate aerobes. B) facultative anaerobes. C) aerotolerant anaerobes. D) obligate anaerobes. E) either facultative anaerobes or aerotolerant anaerobes.
either facultative anaerobes or aerotolerant anaerobes.
mechanical vectors
not required as hosts by the pathogens they transmit; only passively carry pathogens to new hosts on their feet or other body parts ex: cockroach walking though buffet with salmonella on its feet
low level germicides
eliminate vegetative bacteria, fungi, protozoa, and some viruses
sterilization
eliminates organisms and their spores or endospores
artificially acquired passive immunity
ex: bit by a poisonous snake exposed to toxin, get antisera that is antibodies against that toxin, no long term protection from toxin but short term protection
alternative complement activation pathway involves
factors B, D, and P
what two things do fungi produce
filamentous structures spores
Concentration or intensity of treatment
follow instructions for diluting, sometimes diluting makes it more effective, how much heat, radiation, pressure are you using
mutation rate and formula
for a given gene is often defined as the number of mutations formed per cell division. a (mutation rate) = m (number mutations) per number of cell divisions.
function of rRNA
form ribosomes
structure of GroEl and GroEs
form stacked ring with hollow center like barrel
orthologs
genes in different species that evolved from a common ancestral gene by speciation functions essentially the same but occur in 2/ more different species
Transformation is a form of horizontal gene transfer that involves homologous recombination. Homologous recombination is
genetic recombination between similar or identical nucleotide sequences
how does bacteria defend themselves against viruses (3)
genetic resistance restriction endonucleases CRISPR
homologs
genomes of different species but evolved from common ancestral gene and produces proteins similar in function
structures in Herpes simplex virus
glycoprotein spikes envelope Tegument: collection of 15 kinds of virus encoded proteins and proteins of previous host DNA : ds packed in icosahedral capsid nucleocapsid
what are some properties of salmonella?
gram negative rod shaped motile with peritrichous flagella somantic (O), capsular (Vi), and (H) flagella-----over 2500 serotypes
/E. coli/
gram negative bacteria that is part of the normal gut flora; can cause diarrhea and UTIs; pathogenic strains contain a toxin that damages the kidneys
parasitism
parasite derives benefit from its host while harming it parasite that causes disease= pathogen ex: leech to human, fetus to mom
primary
pasteurization kills ____ pathogens but not all
what is most closely associated with a beta-lactam ring
penicillin
A bacterial strain lacking the RecA protein will be unable to
perform generalized recombination.
stationary phase
period of equilibrium; microbial deaths balance production of new cells. caused by decrease nutrients and oxygen, increase in waste products
The SecA dependent secretion pathway delivers proteins to the
periplasm
reportable diseases
potential bioterror agents- anthrax, food borne illnesses- botulism, cancer, antibiotic resistant bacteria, sever illness
biological origin of HIV
primate virus Simian immunodeficiency virus (SIV) which entered human population from eating primate meat
Propionibacterium
propionic fermentation bacteria
propionic acid and CO2
propionic fermentation chemicals
swiss cheese
propionic fermentation products
transversion mutation
purine for pyrimidine (vice versa)
physical mutagens
radiation-x-rays, UV light are examples of
Antisepsis
reduction of the number of microorganisms on living tissue
induced mutations
refers to those mutations in the DNA resulting from exposure to toxic chemicals or to radiation
function of small RNA
regulates transcription or translation
High mutation rates generate multiple virus strains with differing properties of
replication tissue tropism resistance to antivirals
categorize types of ancient retroviral sequences present in the human genome
retroelements retrotransposons
Guanosine tetraphosphate (ppGpp) serves as a signal to the cell that
ribosome synthesis should be curtailed aka stringent response
denature, protein
temp and pH ___ the enzyme by changing the ____ structure
Naturally acquired passive immunity
temporary type of immunity, preformed antibodies, natural acquisition of these occurs through breastfeeding, breast milk contains antibodies
what is the purpose of MAC?
the MAC forms holes in the cell membrane and the bacterial cell is lysed
what does x-ray crystallography provide?
the STRUCTURE of the molecule using x ray photographs
adaptive immunity
the ability to recognize and remember specific antigens and mount an attack on them
Decimal reduction time
the amount of time it takes for 90% of population to die (usually talking about chemical)
Metabolism
the collection of controlled biochemical reactions that take place within a microbe/ cell
The segmented genome of influenza was initially thought to be packaged at random into new virions. New evidence shows
the eight segments link together before packaging.
proteome
the entire set of proteins expressed by a given cell or group of cells
These dimers are repaired by
the enzyme DNA photolyase and exposure to light
antisepsis
the inhibition or killing of microorganisms on *living tissue* by the use of a chemical antiseptic
an antiserum is
the liquid portion of blood used for immunization
what are the complement proteins made by?
the liver
What is oxidation?
the loss of electrons from a molecule.
minimum inhibitory concentration (MIC)
the lowest amount of an antimicrobial that will inhibit bacterial growth; clear tube indicates no growth
minimum bactericidal concentration (MBC)
the lowest amount of an antimicrobial that will kill bacteria
Thermal death point
the lowest temperature that kills all of the cells in a broth in 10 minutes
A clinical sample labeled as "sputum" was collected from A) the skin. B) the blood. C) the central nervous system. D) a piece of tissue. E) the lungs.
the lungs.
opsonization refers to?
the process of antigen being covered by antibody
sanitization
the process of disinfecting surfaces and utensils used by the public- *public health standard*
attenuation is
the process of reducing virulence
degerming
the removal of microbes from a surface by *mechanical means* such as scrubbing
the larger the therapeutic index, ______________
the safer the drug!
what is a tuber?
the thickened part of a potato stem which is eaten
pasteurization
the use of heat to kill pathogens and reduce the number of spoilage microorganisms in *food and beverages*
latent diseases
those in which a pathogen remains inactive for a long period of time before becoming active ex: herpes
obligate halophiles
those that grow in up to 30% salt, require high osmotic pressure. will burst in freshwater
Alkalinophiles
thrive in basic pH as high as 11.5
which is another term for supercoiled?
tight packing
generation time
time required for a cell to grow and divide
disinfectant that contains alcohol
tincture or bromine
Which type of DNA uptake is dependent on viruses?
transduction
Pasteurization
treating a substance with heat to kill or slow the growth of pathogens
if a patient has a life threatening fungal or protozoal infection what is treatment plan? what is its mechanism of action?
treatment: IV liposomal amphotericin AND oral intraconazole for a couple months MOA: causes pores in fungal wall leads to leakage of cell contents causing cell death
T/F: Following base removal, DNA polymerase can add nucleotides in the 5' to 3' direction.
true
T/F: Genes controlled by an activator have ineffective promoters.
true
T/F: Glyceraldehyde-3-phosphate and 3-phophoglycerate are three-carbon molecules produced during the Calvin Cycle.
true
T/F: Plastoquinone is the primary electron acceptor for electrons leaving photosystem II.
true
T/F: The encoded protein of the DNA sequence 3' TAC CGC TTA CAT GAG 5' (aasume it is the minus strand) has the amino acid sequence met-ala-asn-val-leu. Use the genetic code below.
true
Is a sterile surface aseptic?
yes, but an aseptic surface is not sterile
Naturally acquired active immunity
you got whatever it was, you got sick with it, you developed an immune response, now immune to it ex: chicken pox
Betadine
Iodophors include
lactic acid
lactic acid fermentation chemicals
True
Ionizing radiation is more effective than nonionizing radiation in killing or inactivating microbes
Hybridization probes to digest the DNA sample
Which of the following techniques is mismatched with DNA fingerprinting?
Sporicide
Which of the following types of control agents would be used to achieve sterility?
During maturation of formation of phage particles,
a few phage heads may surround fragments of host bacterial DNA
psychrophile
microorganism requiring temperatures ranging from approximately -5 degrees Celsius to 20 degrees Celsius
Ames
A screening system called the _______ test is used for detecting chemicals with carcinogenic potential.
the target organisms but not vertebrate cells.
Selective toxicity refers to damage to
What are the 2 most common VIRAL GI pathogens?
1. Rotavirus 2. Norovirus (stomach flu)
TRUE
5) The deinococci can be categorized as extremophiles.
Oxygen
A microorganism that does not have catalase or superoxide dismutase would find it difficult to live in an environment with
histone
A nucleosome is a linear chromosome wound around the
38 (prokaryotes)
Aerobic Respiration: Amount of ATP
False
After binary fission, daughter cells will differ genetically.
29) Which of the following criteria is most useful in determining whether two organisms are related? A) Both ferment lactose. B) Both are gram-positive. C) Both are motile. D) Both are aerobic. E) Each answer is equally important.
B) Both are gram-positive.
4) What is the outstanding characteristic of the Kingdom Fungi? A) All members are photosynthetic. B) Members absorb dissolved organic matter. C) Members absorb dissolved inorganic matter. D) All members are microscopic. E) All members are macroscopic.
B) Members absorb dissolved organic matter.
25) Organism A has 70 moles % G+C, and organism B has 40 moles % G+C. Which of the following can be concluded from these data? A) The two organisms are related. B) The two organisms are unrelated. C) The organisms make entirely different enzymes. D) Their nucleic acids will completely hybridize. E) None of the answers is correct.
B) The two organisms are unrelated
7) A genus can best be defined as A) a taxon composed of families. B) a taxon composed of one or more species and a classification level lying below family. C) a taxon belonging to a species. D) a taxon comprised of classes. E) the most specific taxon.
B) a taxon composed of one or more species and a classification level lying below family.
thermophile
microorganism requiring temperatures ranging from approximately 45 degrees Celsius to 80 degrees Celsius
Recombinant DNA technology
Before the advent of biotechnology, diabetics would use insulin harvested from cows. Now they receive human insulin produced through
44) Which of the following characteristics indicates that two organisms are closely related? A) Both are cocci. B) Both ferment lactose. C) Their DNA can hybridize together. D) Both normally live in clams. E) Both are motile.
C) Their DNA can hybridize together
6) Which of the following statements about the members of the Kingdom Animalia is FALSE? A) They are multicellular. B) They are composed of eukaryotic cells. C) They undergo photosynthesis. D) They ingest nutrients through a mouth. E) They are heterotrophs.
C) They undergo photosynthesis.
46) For a serological bacterial identification test to be performed, you must have ________ in your possession. A) DNA that will hybridize to the DNA of the bacterium to be identified B) RNA that will hybridize to the RNA of the bacterium to be identified C) antiserum containing antibodies that will bind to the bacterium to be identified D) fluorescent molecules that will light up when bound to the DNA of the bacterium E) viruses that will specifically infect the bacterium you're trying to identify
C) antiserum containing antibodies that will bind to the bacterium to be identified
26) Nucleic acid hybridization is based on the fact that A) the strands of DNA can be separated. B) a chromosome is composed of complementary strands. C) pairing between complementary bases occurs. D) DNA is composed of genes. E) all cells have DNA.
C) pairing between complementary bases occurs.
cytotoxic T cells
CD8+ T cells Main job is to kill virally infected cells Also kill tumor cells
chemotaxis
Cell movement that occurs in response to chemical stimulus
DnaK, GroEL, and GroES are which kind of proteins?
Chaperonins
what is loaded on to MHC Class I molecules? what is loaded on MHC Class II?
Class I: intracellular bacterial products viral proteins Class II: exogenous bacteria
Group VI: retroviruses/ RNA reverse transcribing viruses
Consists of (+) strand RNA and Reverse transcriptase that transcribes RNA into double stranded DNA then DNA integrated into host genome and directs viral gene expression
which bacteria is gram negative and easy to grow which is highly implicated in foodborne illnesses and urinary tract infections?
E coli
Transferases
Enzymes that catalyze the removal of a functional group and its subsequent attachment to a new substrate are called
11) Which of the following is NOT based on nucleic-acid hybridization? A) DNA chip B) FISH C) PCR D) Southern blotting E) Western blotting
E) Western blotting
14) Which of the following provides taxonomic information that includes the information obtained in the others listed? A) nucleic acid hybridization B) nucleic acid-base composition C) amino acid sequencing D) biochemical tests E) cladogram
E) cladogram
Oxidoreductases
Enzymes that catalyze the removal of electrons from one substrate and addition to electrons to another are called
FADP
Each of the following are electron carriers except
Hepatitis A
Family Picornaviridae (polioviruses, coxsackieviruses, echoviruses, and rhinoviruses - common cold) - ssRNA virus clinical features: incubation 15-45 days, self limiting symptoms: fever, headache, diarrhea, nausea, vomiting, jaundice diagnosis: IgM to HAV, life long immunity prevention: hand washing, sanitation (clean water sources), Hep A vaccine, immune globulin
RNA polymerase
Gene regulation can involve a protein repressor that blocks ______ from initiating transcription.
All of the above have been genetically modified.
Genetically modified organisms include
True
Glyceraldehyde-3-phosphate is an intermediary of glycolysis that can also be utilized in biosynthetic pathways
30
Glycolysis and the Krebs cycle yield 10 molecules of NADH per molecule of glucose. How many molecules of ATP will be made from them in the electron transport system?
glucose -> 2 pyruvate, 2 ATP, NADH
Glycolysis reaction
examples of chaperones
GroEL, GroES, DnaK
Heat-related methods
High temperatures denature proteins and kill organism, can also damage cell membranes, cell walls, and nucleic acids if exposed long enough Thermal death point- lowest temperature that kills all cells in broth in 10 minutes For different organisms it is different Thermal death time- time to sterilize volume of liquid at set temp
Mesophiles
Human pathogens fall into the group called
All of the choices are correct.
Hydrogen peroxide is Sporicidal Fungicidal Bactericidal virucidal
True
Hydrogen peroxide is used in the process of sterilizing instruments such as endoscopes.
The events of binary fission are I. the cell doubles in size II. the DNA is replicated III. the cell forms a septum IV. the cell separates from its offspring The CORRECT order of these events is
II, I, III, IV.
HEPATITIS A (HAV) —> "Picornaviridae"
INCUBATION PERIOD: - long (15 to 45 days) SYMPTOMS: - jaundice - diarrhea - nausea - vomiting - headache - death DIAGNOSIS: - IgM to HAV TREATMENT: - no specific treatment - sef-limiting (2 weeks to several months) - supportive care (people can recover) LIFELONG IMMUNITY VACCINE - approved in 1995
CGU
If a codon for alanine is GCA, then the anticodon is
Insertion
If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATA ETH EBI GRA T?
ADP
In the cell, energy released by electrons is often used to phosphorylate
DNA ligase
In the formation of recombinant DNA, what enzyme is needed to seal the sticky ends of genes into plasmids or chromosomes?
Precursors, catabolism, anabolic
Interaction 2: ______ made in ______ is used in ____ reactions
pathways (metabolic)
Interaction 3: these ________ are shared by both anabolism and catabolism
mucous membranes
Line all body cavities open to the outside environment 2 distinct layers epithelium thin, outer covering living cells tightly packed continual shedding of cells some membranes have specialized cells- trachea have goblet cells that produce mucous which traps microbes, ciliated columnar cells allow you to propel mucous out and get rid of microbes (cough them out) connective layer
Gene Probes
Labeled, known, short stretches of DNA used to detect a specific sequence of nucleotides in a mixture are known as
which of the following binds iron
Lactoferrin, siderophores, and transferrin- all
Freezing
Long term preservation of foods, drugs, and cultures. non sterile. <0 oC
Group II: single stranded DNA viruses
Need host DNA polymerase to make complementary DNA strand Transcription via host RNA polymerase
Group I: double stranded DNA viruses
Make own DNA polymerase or use from host for genome replication Genes transcribed directly by standard RNA pol
Thermoduric
Mesophiles that can survive at high temps briefly
RNA interference (viral defense)
Mechanism where mRNA expressed by viral genome recognized by host protein RNA complex that shuts down further expression
Protein
Mediated transport of polar molecules and ions across the plasma membrane utilizes ________ carrier that binds to the substance and causes a conformational change to allow its movement across the membrane.
difficulties involved in culturing viruses.
Need to grow virus in host cell tropism Tissue culture does not show all properties of organ within living organism and causes loss of virulence factors
Autoclaving
Method of sterilization using steam under pressure. used on laboratory media and glassware
which fungi forms a symbiotic relationship between the roots of the plants and fungal hyphae?
Mycorrhiza associations
______________-acute inflammation of the heart ______________-acute inflammation of the covering membrane of the heart _____________- one of the major causes of infectious myocarditis-starts as respiratory infection but can on rare occasions cause myocarditis.
Myocarditis Pericarditis Coxsakie B virus
The two 3-carbon molecules glucose is split into are converted through a series of steps into pyruvate. During these steps
NAD+ is converted to NADH
second line of defense
Operates when pathogens succeed in penetrating the skin or mucous membranes Phagocytes- cells that are able to engulf and destroy microbes Extracellular killing by leukocytes- white blood cells secrete things to kill other cells Nonspecific chemical defenses- wide variety (not completely non specific, might target virsuses or gram-neg bacteria) Inflammation fever
True
Organisms in the genus Pseudomonas are resistant to quarts.
singlet oxygen
O2 boosted to a higher energy state, very reactive
Hydrogen peroxide
Physical agents for controlling microbial growth include all of the following except
False
Photosynthesis occurs in chloroplast of prokaryotes
bacteriostatic
Placing organisms at 4oC is
Protozoan
Primaquine and chloroquine are drugs used in the treatment of ______ infections.
Transposition
Process whereby DNA independently excises from one location in DNA molecule and integrates elsewhere
how is stringent response triggered
Ribosomes make ppGpp which interacts w RNA pol and lowers its abil to transcribe genes encoding rRNA
Who discovered the X ray crystallography structure?
Rosalind Franklin DISCOVERED but Wilkins stole without her knowledge
At the beginning of the Calvin Cycle, carbon dioxide is attached to _____.
RuBP
which bacteria is cocci shaped, aerobic respiration, and is encapsulated?
S. pneumoniae
adaptive immune system
Specificity antigen epitope clonal expansion somatic hypermutation memory 2 types humoral cell mediated
disrupting membrane integrity.
Surfactants work by
False
Surgeons preparing for an invasive surgical procedure will scrub their hands thoroughly, and then they use a strong alcohol-based hand sanitizer which renders their hands sterile
Nucleotides
The DNA of an organism is made up of subunits called
TRUE
The Kirby-Bauer test uses an agar surface seeded with the test bacterium, and small discs containing a specific concentration of several drugs are placed on the surface
TRUE
The MIC is the smallest concentration of an antimicrobial required to inhibit the growth of the microbe.
True
The MIC is the smallest concentration of an antimicrobial required to inhibit the growth of the microbe.
Sterilization
The process that completely destroys all microbial life, including spores.
transfer RNA.
The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called
Sterilization
The process that destroys or removes all microorganisms and microbial forms, including bacterial endospores, on inanimate objects is
Although some microbes will be killed, those embedded deeply within the biofilm are protected from environmental challenges.
The biofilm that forms in your shower ("shower curtain scum") can tolerate exposure to hot water when you shower and is resistant to desiccation between showers. The icrobes in the biofilm are not endospores, so what is the best explanation for their survival under these conditions?
enzymes
The cell's metabolic reactions involve the participation of _________ that lower the activation energy needed for the initiation of a reaction.
All are correct (bacterial chromosomal mutations, synthesis of enzymes that drug structure, prevention of drug entry into cell, alteration of drug receptors on cell targets)
The cellular basis for bacterial resistance to antimicrobials include
the growth of other organisms sharing their habitat was inhibited, thus giving them a selective advantage.
The production of antibiotics by microbes evolved so that
Replication
The duplication of a cell's DNA is called
Sanitization
The method of removing vegetative microbial life forms and debris to reduce contamination to safe levels is termed ______.
Excision repair
The process in which mutations are removed and the correct bases added is called
log phase
The period of exponential growth of bacterial population. Will grow if has adequate nutrients and a favorable environment
Lag Phase
The phase of the bacterial growth curve in which newly inoculated cells are adjusting to their new environment, metabolizing but not growing at an exponential rate, is the
Exponential phase
The phase of the bacterial growth curve that shows the maximum rate of cell division is the
exponential phase
The phase of the bacterial growth curve that shows the maximum rate of cell division is the
synthetic DNA oligonucleotides.
The primers in PCR are
endocytosis
The process by which a cell uses ATP to enclose a substance in its membrane, by forming a vacuole and engulfing it, is called
Does washing your hands with antibicrobial soap (vs regular) and spraying your house with Lysol regularly improve your health?
There is little evidence to support idea that regular use of antimicrobials in a home setting improves health Tryclasan doesn't help with mechanical hand washing Tryclasan driving antibiotic and antimicrobial resistance in bacteria More soaps with no tryclasan People don't use Lysol properly
Which of the following is an acronym for a type of infection given in the report?
UTI
Lyophilization
Vials of microorganisms that undergo the freeze-drying process, called _____, will remain preserved and viable for years
Do fungi have a cell wall?
Yes made of chitin NOT made of peptidoglycan (murein)
Fermentation a. requires an organic electron acceptor b. requires oxygen c. only occurs in aerobic organisms d. is equivalent to aerobic respiration in ATP production e. none of the choices is correct
a. requires an organic electron acceptor
Differences in ways of acquiring immunity
artificial or natural- time course is same active response- initial injection or infection allows you to develop immune response, develop antibodies against that bind better after booster passive- provides quick protection but no protection long term
surgical procedure free of microbial contaminants
aseptic
if a mold forms conidia, what is the form of reproduction? what is its use?
asexual reproduction use: medical hyphae: have septate
When a surgeon conducts a cardiac bypass operation by transplanting a piece of vein from a patient's leg to the same patient's heart, this is
autograft
Astrovirus +ssRNA, Naked, icosahedral Spread Fecal/oral More mild More common in ___________
childhood
what structures are unique to fungi?
chitin (cell call) glucan (glucose polymer)
preservation of beef jerky from microbial growth relies on which method of microbial control
desiccation
T or F: Phagocytes are completely non-specific, and do not have receptors for bacterial components
false
Use the genetic code below to translate the mRNA sequence 5' AUGCACUCAAGAGCAGUA 3'
methionine-histidine-serine-arginine-alanine-valine
what are antibodies produced against in lupus?
nucleic acids and chromosomal proteins
what does virion consist of
nuclein acid genome and protective protein capsid
an anti-antibody is used when
the antigen is an antibody
If a bacterial cell is competent, it means that
the bacterium can import free DNA fragments and incorporate them into its genome.
What would be the consequnce of a transposon inserting into the site shown by the red arrow? (tetracycline-resistance gene)
the bacterium would likely become sensitive to tetracycline
where can listeria spread to?
the brain and placenta
Incineration
the burning of solid waste, sterile, 1 sec at more than 1000oC,
Cells prefer to use carbohydrates as energy sources because
they are such good donors of hydrogen and electrons
How many bacteria were scanned in an effort to find those with the mcr-1 gene?
55 x 10^3
FALSE
6) All gram-negative bacteria are classified as proteobacteria.
RNA
A primer comprised of _______ is needed at the origin of nucleotide addition.
a saprobe derive nutrients from dead plants and animals, but a parasite derives nutrients from living plants and animals.
A saprobe differs from a parasite in that
what kind of cellular respiration do fungi have?
1. obligate aerobe 2. facultative anaerobe (yeast-candida) 3. take exogenous source of organic carbon for growth 4. tolerate extreme temperature (extremophile) MOST ARE OBLIGATE AND FACULTATIVE AEROBES
what can cause a fever?
1. pathogens 2. immunological reaction after vaccine 3. tissue injury (heart attack) 4. pyrogens (toxins produced by bacteria)
what are three reasons for ab resistance?
1. plasmids 2. transposons 3. efflux pumps
Transformation
In Griffith's experiments with Streptococcus pneumoniae, rough nonencapsulated streptococci were converted into smooth encapsulated streptococci in the presence of the heat-killed smooth encapsulated streptococci. Which microbial process had Griffith identified?
Hydrogen
In addition to electrons, which of the following is also involved in electron transfer?
38
In bacterial cells, when glucose is completely oxidized by all the pathways of aerobic cellular respiration, what is the maximum number of ATP generated ?
2 types of immunity
Innate immunity- nonspecific diseases (specific for a certain genera of microbes but not as specific as adaptive) Rapid (minutes to hours) nonspecific Adaptive immunity Initial response takes days Specific to a given antigen, particular microbe
True
Inorganic nitrogen must be converted to ammonia to be used by a cell.
tailed viruses
Instead of icosahedral capsid of head coat - get delivery device Has tail fibers that can stabilize structure on host cell surface to infect and make virions inside cell
Disk Diffusion Susceptibility test
Kirby-Bower antibiotic susceptibility testing Little paper disks with antibiotics in them, put on plate with specific concentration of bacteria on it, these concentrations correlated with clinical outcomes, zone of inhibition tells if it is curable or not clinically
2 acetyl CoA -> 4 CO2, NADH, FADH, 2 ATP
Krebs cycle reaction
gene probes
Labeled, known, short stretches of DNA used to detect a specific sequence of nucleotides in a mixture are known as
O2
Aerobic Respiration: final e- acceptor
Yes
Aerobic Respiration: is O2 required
which chemotaxis diffuses and forms a concentration gradient that enters the capillary bed to activate the immune response? what does it do?
C5 chemotaxin 1. margination: neutrophils sense it and enters the capillary bed 2. diapedesis: crosses endothelial cells 3. extravasation: moves into tissues this homing mechanism guides neutrophils to their targets
In contrast to animal viruses and bacteriophages, plant viruses infect cells by mechanisms that involve: A. receptors B. host proteins C. membranes D. physical damage
D. physical damage
CRYPTOSPORIDIUM
DISEASE: - cryptosporidiosis FEATURE: - apicomplexa (apicoplast derived from bacteria) - can be treated with antibiotic (tetracycline) - spore forming - contaminates food
TRICHINELLA SPIRALIS (adult nematode) ***
DISEASE: Trichinosis FEATURE: - Adult roundworm (nematode) - a lil bit similar to tapeworms - infection from pork! - forms cyst!
How does Helicobacter pylori survive in the stomach?
It produces large amounts of UREASE to neutralize the stomach acid
Which of the following does NOT cause mutations?
Exposure to antibiotics
how does bacterial conjugation occur?
F+ (male) carries F plasmid and transfers it to F- (female) that has no F plasmid via sex pilus made by F + (male)
what is the result of bacterial conjugation?
F- female becomes F+ male
1) The cell membranes of all three domains are composed of straight carbon chains attached to glycerol by ester linkage.
FALSE
innate immunity
General defenses against invaders Barriers- skin and mucous membrane Unfavorable environments- skin has salt on it Processes that rid body of invaders- vomiting, diarrhea, urination Immune cells with non-specific actions- phagocytes that can engulf various types of microbes Proteins that interact with microbes and immune cells- complement cascade Inflammation and fever- very important parts of immune response
reverse transcriptases
Geneticists can create sequences of DNA from RNA using enzymes called
genes, mutation
HGT allows for transformation of ___ without a mutation. It also provides ______
conditions that favor the emergence of viral pathogens.
Human pathogens come from other humans or related animals (vectors)
80%
Humans display how much DNA similarity with mice?
which Ab serotype is the main (80%) classic immunoglobulin that is released in an extracellular infection?
IgG B Cell Receptor molecule
If you have _____________ against the virus you can stop the disease-the virus cannot go to its target organ. The virus however is still replicating and can spread _______.
IgG antibodies fecally
desiccation
Removal of moisture by dehydration is called
why is HIV the most rapidly evolving pathogen known?
Replication creates about one mutation per progeny virion creating quasispecies and needs a combination of antiretroviral drugs to treat it
True
Resistance genes can be transferred to other bacterial cells during transformation, transduction, and conjugation.
Glycolysis and the Krebs cycle
Substrate-level phosphorylation occurs in
Pseudomonas syringae
The commercial product Frostban consists of a genetically altered bacterium which prevents ice crystals from forming on plants, thereby reducing freezing of plants and financial distress to the farmers as a result of freezing weather. This product contains a strain of ______.
They form trihalomethanes with organic compounds
The following is not true of chloramines.
Active Transport
The movement of substances from lower to higher concentration across a semipermeable membrane via a specific protein carrier and cell expenditure of energy is called
Promoter
The nontranscribed region of DNA to which RNA polymerase binds to initiate transcription is called the
superoxide dismutase, peroxidase, catalase
What are three enzymes that they produce to detoxify these oxygen products?
catalyze reactions
What do enzymes do?
Adenisine triphosphate
What does the abbreviation "ATP" stand for?
Autoclave
What instrument is most effective for pressure temperature sterilization ?
In a mutualistic relationship, the organisms are dependent upon each other.
What is the difference between mutualism and synergism?
ATP for anabolism, movement, active transport
What is the energy made during catabolism used for?
These enzymes are a defensive measure of bacteria to defend themselves against invading DNA of bacteriophages.
What is the evolutionary advantage of bacteria producing restriction endonucleases?
C6H12O6 + 6 O2 -.> 6 H2O + 6 CO2+ Energy
What is the overall reaction of the aerobic respiration of glucose?
To provide energy
What is the role of ATP in metabolism
toxoid vaccines
chemically or thermally modified toxins can't cause any toxic effects but once you mount immune response to it, produce antibodies against it, will neutralize real toxin if you ever see it useful for some bacterial diseases that are mediated by toxins stimulate antibody-mediated immunity needed to neutralize toxins require multiple doses- booster shots bc toxins are small are relatively simple ex: tetanus
which have much broader effectiveness against a variety of gram pos, gram neg, and multiple resistant pathogens and may include anaerobes?
extended spectrum agents
Flow cytometer
When it is important to count the number of cells, determine cell size, and differentiate between dead and live cells, a(n) ______ is used.
False
When micro RNA molecules malfunction, their effect is limited to the inhibition of protein production, which results in tumor growth
Commensalism
When microbes are in a close nutritional relationship and one benefits but the other is not harmed, it is called
Synergism
When microbes live independently but cooperate and share nutrients, it is called
catabolic reactions (ATP) or light
Where do cellular microbes get their energy
Genes
Where do cellular microbes get their enzymes?
cytoplasm
Where does glycolysis occur in eukaryotes?
True
Whether an organism is a phototroph or a chemotroph depends on its source of energy.
False
Whether an organism is an autotroph or heterotroph depends on its source of nitrogen?
Add DNA polymerase and nucleotides at 72° C.
Which PCR step synthesizes complimentary DNA strands?
Trimethroprim
Which antimicrobial does not interfere with protein synthesis?
Rifampin and quinolones
Which two antibiotics affect nucleic acids of bacteria?
Fleming
Who is considered to be the father of modern antibiotics?
They freeze at body temp
Why do extreme thermophilic bacteria not cause food spoilage?
-Intracellular replication complex
Within a host cell, the viral gene products direct the cell's enzymes to assemble progeny virions at "virus factories" called replication complexes.
Structure of tRNA
a cloverleaf with an anticodon at one end and an amino acid at the other
A "nosocomial" infection is an infection acquired through
a hospital stay
an autoantigen is
a normal body component
Glycolysis takes place in the _______.
cytoplasm
In ABC transporters, the ATP binding cassette faces the
cytoplasm
list possible protein delivery location in a bacterial cell
cytosolic membrane cell wall secreted
subacute disease
durations and severities of disease somewhere between acute and chronic diseases Ex. Subacute bacterial endocarditis
Which of the following organisms would be most likely to contaminate a jar of pickles? A) a neutrophile B) a thermophile C) an acidophile D) an obligate anaerobe E) a mesophile
an acidophile
facultative anaerobes
an organism that uses oxygen if it is present, but is capable of switching to fermentation or anaerobic respiration if oxygen is absent
Barophile
an organism which can only exist at pressures found at great depths ex: deep sea microbes
Changing your T-shirt for one of a different color is analogous to ________.
antigenic variation
problems with inactivated vaccine
antigenically weak don't stimulate great immune response whole agent vaccines may stimulate a inflammatory response do not stimulate contact immunity
What do medical personnel administer to counteract various type I hypersensitivities?
antihistamine, bronchodilator, corticosteroid, epinephrine
selective toxicity
antimicrobials must kill microbial cells but not the host's cells, be able to differentiate between human cells and infectious agent
which is most harmful?
Lacking cytotoxic T cells- knocks out a lot of viral immunity Lacking helper T cells Lacking B cells- no antibody related immunity but still have T cell Lacking Tregs- autoimmune disease a: Lacking helper T cells- activate B cells, cytotoxic T cells, macrophages, very limited adaptive immunity
Microbial antagonism
Normal microbiota protects the body by competing with pathogens Consume all nutrients available so that there are none left for pathogenic organisms Create an unfavorable environment for other microorganisms by producing their own antibiotics against other microbes
compare and contrast innate vs adaptive immunity
innate: -general protection -immediate response -early phase -no memory adaptive: -highly specific for antigen -late phase -lag time between exposure and response -memory
nucleoside analog inhibition of nuclei acid synthesis antiviral drug
looks like nucleotides but analog of it in which when incorporated, it can stop transcription HIV infections
Where can B cells be found
lymph nodes, spleen, red bone marrow, intestinal wall
mesophile
microorganism requiring temperatures ranging from approximately 15 degrees Celsius to 45 degrees Celsius
which bacteria is a gram negative diplococci, grows cery slowly, ferments glucose/maltose and is a tropism for the brain endothelial cells in CNS?
neisseria meningitidis
Herpes simplex virus (HSV) causes latent infection in the region of the
neurons of the ganglia.
which are polymorphonuclear luekocytes that are responsible for guarding blood, skin, and mucous membrane against infection?
neutrophils
vertical transmission
occurs from mothers to their offspring
A deficiency of both B cells and T cells is most likely
primary immunodeficiency
quorum sensing
process by which bacteria measure their density in an environment by utilizing signals and receptor molecules; microbial cells are stimulated to release chemicals as the population grows to monitor its size
uncoating
process in which capsid comes apart releasing viral genome into cytoplasm
what is the process by which foreign DNA is introduced into a bacterial cell? what are the five steps?
process: transformation 1. donor bacterium 2. cell lysis 3. binding to recipient 4. DNA uptake 5. recombination
which class of surfactant is most solute in water
quaternary ammonium compounds
what medication was used to treat malaria?
quinine
define retrotransposons of ancient retroviral sequences present in the human genome
retain only particle retroviral elements by many maintain RT to copy themselves into other genome locations
retrovirus
reverse-transcribe their RNA genome into dsDNA, which is then integrated into the host chromosome.
hemolytic disease of the newborn is caused by antibodies against which major blood group antigen
rhesus antigen
replicative transposition
sequences copies itself into new host DNA while copy remains within original host
how does lactoferrin protect body?
sequesters iron within body iron: key nutrient for bacterial growth
Which of the following methods provides information about the number of living cells in a sample of bacterial culture? A) serial dilution and viable plate count B) membrane filtration C) a Petroff-Hauser counting chamber D) flow cytometry E) a Coulter counter
serial dilution and viable plate count
complement system involves
serum proteins involved in nonspecific defense
if a mold forms spores, what is the form of reproduction? what is its use?
sexual reproduction use: food and environmental hyphae: aseptate
phase variation
shape shifting, renders useless to antibiotics for old structure
post translational modification: removal of translated signal sequences
short trails of a.a. that help in directing protein to specific cellular compartment
During the electron transport chain in bacteria, protons are
shuttled to the outside of the cell membrane
function of transfer RNA
shuttles amino acids
which disease occurs when there are not enough healthy RBC to carry adequate oxygen?
sickle cell anemia missense mutation symptoms: increased suspectability to infection
role of viruses on global scale
significant role in the cycling of minerals and nutrients carbon balance
which type of mutation has little to no implication to the phenotype?
silent mutation why? because it codes for the same amino acid
insertion sequences
simple transposable element consisting of transposase genes flanked by short inverted repeat sequences that targets transposase
reservoir
sites where pathogens are normally maintained as a source of infection animal human carriers- humans with active diseases are important reservoirs of infection for other humans non-living- soil, water, food
what is the most difficult first line of defense to penetrate?
skin
How do organisms get in and out of human hosts
skin- hair follicles, sweat glands, abrasions, cuts, bites, scrapes, stab wounds, surgery, larvae of parasitic worms burrow, fungi digest outer layer mucous membranes- respiratory tract is most frequent portal of entry, enter nose and mouth in air, dust particles, and droplets of moisture; eyes (cold and influenza), urinary tract, gastrointestinal tract, reproductive tract placenta- pathogens can only cross in 2% of pregancies parenteral route- not a portal of entry but a means by which the portals of entry are circumvented- pathogens must be deposited directly into tissues beneath skin or mucous membranes- nail, thorn, hypodermic needle
Plasmid
small molecules of DNA that replicate independently of the chromosome. These are found in the cytoplasm of DNA.
The Most Probable Number (MPN) method is used A) to estimate numbers of cells in samples with a high density of bacterial cells. B) when samples contain obligate anaerobes. C) to estimate numbers of cells in samples with a low density of bacterial cells. D) to isolate autotrophic bacteria. E) to determine the generation time of bacterial isolates.
to estimate numbers of cells in samples with a low density of bacterial cells
antibiotic mechanisms of action targeting translation (6)
streptomycin, tetracycline, Chloramphenicol, puromycin, erythromycin, fusidic acid
what is a fungal infection that involves the skin, subcutaneous tissue, and lympatics? what is an example of one disease?
subcutaneous mycoses example: sporotrichosis: produces lumps/modules and ulcers on the lymph nodes and the skin
Which of the following binds to the active site of an enzyme?
substrate
what is a common fungal infection that occurs on the skin, hair, and nails? what are two examples?
superficial/cutaneous mycoses 1. tinea pedis 2. vaginal candidiasis (yeast infection)
The absence of ________ leaves obligate anaerobes susceptible to killing by oxygen. A) carotenoids B) superoxide dismutase C) peroxidase D) vitamin E E) catalase
superoxide dismutase
functions of quorum sensing
synthesis, secretion, extracellular accumulation of small autoinducer signaling molecules
autoimmune disease
systemic lupus eryhtematosus (not a hear attack, acute anaphylaxis, farmers lung, graft-versus-host disease)
what cell facilitates cell mediated immunity? what are its major functions?
t cells 1. directly kill/inactivate bacteria and viruses, and tumors 2. controls and activates immune and inflammatory responses
the longest 1/2 life
tRNA and rRNA: hours
RNA comes in many forms in the cell, and their structure and longevity are determined by their function. Which of the following has the longest half-life?
tRNA—shuttles amino acids during translation
memory
takes a long time to respond the first time it sees a new antigen, but upon secondary exposure it can respond really quickly because have produced memory cells- don't need as many signals to become active- activated very quickly, basis of vaccination
sterilization
the eradication of *ALL* organisms, including bacterial endospores and viruses
glycocalyxes
the extracellular matrix in biofilms are made up of ____
protective barrier
the function of the extracellular matrix in biofilm is a ____
hot air
used for Water sensitive materials (powder, oils, metals), sterile, 160oC, 2 hours 171oC, 1 hour
PABA is
used to synthesize folic acid
what does yeast (histoplasma) enter in humans?
the macrophages
affinity maturation
the mechanism during an immune response that produces antibodies with strong ability to bind antigen
Hand Foot and Mouth disease not the same disease seen in animals Oral and pharyngeal ___________ first _______ travels to soles of feet and hands, can also spread to arms and legs. Main cause ___________ Only very rare ____________ and all recover completely. Less common ____________-found endemically in east and Southeast Asia can have severe neurologic complications. EV71 cases of Hand Foot and Mouth Disease can have complications of ____________, encephalitis, and paralysis, and death (<0.5%)
ulcerations Rash Coxsakie A complications enterovirus 71 EV71 cases of Hand Foot and Mouth Disease can have complications of Meningitis
to reproduce
the ultimate function of metabolism
The main advantage for bacteria that have the ability to carry out conjugation and other forms of genetic exchange is that
they become genetically diverse
how are angry macrophages activated?
through C3b, C reactive protein, interferon gamma, and LPS
how are heavy and light chains formed (H & L chains)?
through combining and shuffling the VDJ gene segments
how does one get listeria infection?
through ingestion of food leads to meningitis
how do macrophages kill microrganisms?
through secretion of hydrolytic enzymes formation of a phagolysosome
where do t cells originate?
thymus
How does bacterial cell deal with mRNA lacking stop codon?
tmRNA has alanine and mRNA end encodes peptide tag aminoacyl-tRNA enters A site and peptide bond forms between stalled polypeptide and alanine mRNA part of tmRNA displaces old mRNA and is translated Add 10 amino acid peptide tag to carboxyl end marking destruction Stop codon in tmRNA triggers release Help protein brings useless polypeptide to protease and gets degraded
mucus-secreting membranes are found in the
urinary system, digestive cavity, and respiratory passages
which bacteria causes a serious problems, especially in hospitals, and is resistant to penicillin treatment?
vancomycin resistant enterococcus
Intravenous
very high concentration of drug in short period of time, keep that concentration high over an extended period of time, directly into blood, potential issue- if its something that has toxicity to liver or kidneys, more likely to cause problems
Ultrahigh-temperature sterilization
very high temp, above boiling point, but for very short period of time, achieve sterilization, instead of just reduction, basically sterile, affects proteins, can alter taste
how do yeast divide and grow?
via budding, a form of asexual reproduction bud: is called blastoconidia
The ________ method provides an estimate of the CFUs (colony-forming units) in a sample. A) Coulter-counter B) viable plate-count C) streak-plate D) turbidity E) direct microscopic-count
viable plate-count
what is the different between virulent and temperate phage?
virulent: lytic cycle only temperate: can switch between lytic and lysogenic
What is an important feature of Helicobacter Pylori?
- The only bacterium that can colonize stomach - can be detected and treated
human digestive system defenses
- high acidity of stomach (no defenses against bacteria in stomach other than its acidity) - IgA: secretive antibody on mucosal surface, 1st line of defense - phagocytic cells and tissues rich in lymphocytes underneath the mucosal membrane: both defend against pathogens and sample intestinal content - endogenous organisms in the intestines (micro biome): more in number than cells in human body
DEFENSE OF THE DIGESTIVE SYSTEM
- high acidity of stomach (ph ~1) - IgA antibody - Phagocytic cells and tissues - microbiome (endogenous organisms in the intestines)
ROTAVIRUS "Rotaviridae"
- most common cause of SEVERE DIARRHEA IN CHILDREN - vaccines present
NOROVIRUS
- most common cause of foodborne infections - symptoms: diarrhea, vomiting, dehydration
Which of the following genes are likely to be found on a plasmid rather than on bacterial chromosome? Check all that apply.
-BT toxin gene -chlormaphenicol-resistance gene -oil degradation enzyme genes
What type of molecule(s) could the following be? Check all that apply. AGCGCCGCAACGC
-DNA -RNA
Match the enzymes involved in DNA replication with their functions.
-DNA gyrase--temporary breaking of DNA strands -helicase--unwinding the DNA helix -DNA ligase-- joining fragments of DNA -DNA polymerase--DNA synthesis -Primase--RNA primer synthesis
Which of the following statements about polymerases are INCORRECT?
-RNA polymerase can only add nucleotides to an existing nucleotide sequence -RNA polymerase synthesizes a new strand of RNA from an amino acid template
Which of the statements about DNA and RNA are FALSE?
-RNA polymerase requires a primer -Eukaryotic RNA is typically polycistronic
Consider the figure below and check all the TRUE statements.
-a vancomycin-resistant S. aureus mutant is created -in order for S. aureus to become vancomycin-resistanct, conjugation must have occured between the E. faecalis and the S. aureus -either the S. aureus of the E. faecalis must have a conjugative plasmid
Relationship between catabolic reactions and anabolic reactions.
-catabolic processes harvest energy released from the breakdown of compounds to make ATP -anabolic processes use energy from ATP to drive synthesis of molecules used to make up cell structures
Match each of the following types of enzymes with its description.
-constitutive:synthesized constantly, these enzymes usually play a critical and indispensable role in central metabolic pathways -inducible: not routinely produced at significant levels, but their synthesis can be turned on when needed. These are often used in the transport and breakdown of specific energy sources. -repressible: these are produced routinely, but their synthesis can be turned off when they are no longer required. These are generally used in anabolic (biosynthetic) pathways.
Please select the statements that describe features of transcription and translation found in eukaryotes but not in prokaryotes. Check all that apply.
-genes are interrupted by intervening sequences -a tail of multiple adenine ribonucleotides is added to the mRNA transcript -the mRNA transcript must pass through pores to get out of the nucleus -the RNA transcript is processed to remove introns and splice together exons
What do we learn about E. coli from this report? Check all that apply.
-it is Gram-negative -it can cause urinary tract infections
Which of the following play a role in microbial sensing of the environment?
-quorum sensing -two component regulatory systems -antigenic variation -phase variation -sensor and response regulators
Which of the following compounds can be generated from precursor metabolites produced during glycolysis? Check all that apply.
-some small amino acids like alanine, leucine, and valine -peptidoglycon, a component of bacterial cell walls
Consider the figure and check the CORRECT statements. (The wrong nucleotide is incorporated during DNA synthesis) Check all that apply.
-the nucleobase shown in yellow should be C -the CH3 groups alert DNA polymerase to which DNA strand is the template strand -without the CH3 groups, it is possible that the mismatch repair system would replace the G nucleobase (purple arrow) with an A
Which of the following statements accurately describe biochemical pathways? Choose all that apply.
-they convert an initial substrate through a series of steps into an end product -they are well-organized and structured -they can be linear, branched, or cyclical -they are carefully regulated
In order for a cell to make ribosomes, which of the following must be happening?
-transcription -translation
Repair mechanisms that occur during DNA synthesis are: 1. mismatch repair 2. proofreading by DNA polymerase 3. light repair 4. excision repair 5. SOS repair
1 & 2
how often does mutagenesis occur in spontaneous mutations?
1 in 10^6 to 10^8 per generation mutagenesis occurs at a CONSTANT rate
FALSE
1) Bacterial predators such as Bdellovibrio are members of the betaproteobacteria.
C) facultatively anaerobic gram-negative rods
1) Which of the following best describes the enterics, a bacterial group found primarily in the intestines of humans? A) gram-negative aerobic rods and cocci B) aerobic, helical bacteria C) facultatively anaerobic gram-negative rods D) gram-positive cocci E) endospore-forming rods
steps of CRISPR
1) adaptation: insertion of new spaces into CRISPR locus 2)expression: transcription of CRISPR locus and processing of CRISPR RNA 3)Interference: detection and degradation of mobile genetic elements by CRISPR RNA and Cas proteins
different stages of a one-step growth curve of a viral batch culture.
1) inoculation: inoculation of virus binds to cells 2) eclipse: virions penetrate cells 3) burst: host cells release many viral particles 4)burst size: # virions released per bacterium
Place the following events that occur in DNA replication in the correct order.
1-specific proteins bind the origin of replication and separate the two strands of DNA, forming two replication forks 2-primase synthesizes RNA primers 3-DNA polymerases build DNA by adding nucleotides onto the primers, extending them 4-the leading strand is synthesized continuously while the lagging strand is synthesized in Okazaki fragments 5-a different DNA polymerase removes the RNA primers and replaces them with DNA 6-DNA ligase joins the Okazaki fragments
events in inflammation
1. A cut penetrates the epidermis barrier and bacteria invade 2. Damaged cells release prostaglandins, leukotrienes, and histamine 3. Prostaglandins and leukotrienes make vessels more permeable. Histamine causes vasodilation, increasing blood flow to the site 4. Macrophages and neutrophils squeeze through walls of blood vessels (diapedesis) 5. Increased permeability allows antimicrobial chemicals and clotting proteins to seep into damaged tissue but also results in swelling, pressure on nerve endings, and pain 6. Blood clot forms 7. More phagocytes migrate to the site and devour bacteria 8. Accumulation of damaged tissue and leukocytes forms pus 9. Undifferentiated stem cells repair the damaged tissue. Blood clot is absorbed or falls off as a scab
what are the steps of antigen presentation for MHC Class II?
1. APC captures microbes extracellularly via phago/pinocytosis 2. phagolysosome formation 3. degrades microbe to proteolytic fragments 4. pMHC class II and vesicles with fragment buds off the ER 5. exocytic vesicles and MHC II transported to cell surface for recognition by CD4 cells
how c & a interact
1. ATP made in catabolism is used in anabolic reactions 2. Precursors made in catabolism is used in anabolic reactions 3. These pathways (metabolism) are shared by anabolism and catabolism
Plathyhelminthes (flatworms)
1. Flukes 2. Tapeworms
what two stains are used to identify fungi?
1. GMS stain: lymph tissue 2. PAS stain
How to prevent GI infections?
1. Hygiene (handwashing) 2. Sanitation (clean water sources) 3. Vaccination - poliovirus vaccine - rotavirus vaccine - hepA vaccine Immune globulin (pre and post exposure)
NEMATODES (adult roundworms)
1. Trichinella —> trichinosispork infection) 2. Hookworm 3. Ascaris —> ascariasis 4. Trichuariasis —> 5. Strongyloidiasis —> 6. Pinworms 7. Guinea Worm
what are four reasons why adaptive immunity is highly specific?
1. antigen specificity 2. diversity 3. immunologic memory 4. self and non self recognition
what provides selective toxicity if a bacteria invades the host?
1. cell walls: bacteria have cell walls, humans dont. have selective toxicity of drugs 2. protein biosynthesis: bacteria have different ribosomal subunits than humans- ST is achieved (but not THAT different, so can cause human side effects) 3. DNA/RNA synthesis: if bacteria has DNA, its different than humans (is circular and has topoisomerase enzyme)/ If RNA, bacterial RNA polymerase beta subunit is targeted bc humans dont have 4. nucleotide precursor synthesis: target tetrahydrofolic acid that bacteria have, but humans dont
how are clinical specimens identified?
1. culture 2. microscope 3. detection of species specific DNA and serology: ELIchrom (detects yeast)
what else does the innate immune system recognize besides the antigen?
1. detect danger signals from damaged tissue like uric acid in gout 2. missing or changed self ( like NKC missing in cancer)
what are four events in fungal infection?
1. encounter 2. entry: intact skin barriers (dermatophytes) and spore inhalation (aspergillum), or normal flora overgrowth (candida) 3. spread/multiply: depends on tissue reaction, site of proliferation, and duration of infection 4. damage: depends on virulence factors, size of inoculum, and adequacy of host response
if histoplasma enters the human body as a spore, then what is its life cycle?
1. enters as spore 2. inhale the spore 3. enters the alveoli 4. leads to pneumonitis
what are the big four bacteria?
1. gram positive cocci 2. gram positive rods 3. gram negative cocci 4. gram negative rods
what are some important roles of fever?
1. inactivate microbial enzymes/toxins 2. quick speed of immune response 3. enhance phagocyte activity 4. produce interferons 5. break down lysosomes
after crossing the skin, what does the microorganism encounter next in the line of defense?
1. phagocytic cells (through chemotaxis) 2. pro inflammatory cells (production of inflammatory mediators) 3. natural killer cells 4. antigen presenting cells ( recognize)-macrophages and dendritic cells 5. antimicrobial peptide production 6. complement activation 7. clotting cascade (bradykinin) 8. fever
Streptococcus pyogenes can cause what disease?
1. pharyngitis 2. cellulitis 3. impetigo 4. necrotizing fascitis 5. toxic shock syndrome 6. rheumatic fever (inflammation of the heart) 7. glomerulonephritis (kidney inflammation)
which infections are harder to treat due to Ab resistance?
1. pneumonia 2. Tb 3. gonorrhea 4. salmonellosis
what disease can Streptococcus pneumoniae cause?
1. pneumonia 500,000 cases per year of pneumonia 5 million child deaths per year
what is the chitin layer composed of?
1. polymer of NAG 2. glucans (polymer of D glucose) 3. mannan: (mannose polymer) 4. polypeptides 5. some of capsule ( but rare)* MULTILAYERED
which are the five lymphatic organs?
1. tonsils 2. lymph nodes 3. thymus 4. spleen (LARGEST!!) 5. Peyers patches (lymphatic nodules in the SI)--collectively called GALT (gut associated lymphoid tissue)
what are three reasons why transposons are medically relevant?
1. transposons carry Ab resistance genes 2. they can be transferred between species 3. can cause mutations if inserted into a gene
what is the action of kinins?
1. vascular dilation 2. increased permeability
what are three examples of fungi?
1. yeast: single celled -larger colonies 2. molds: filamentous fungi -multicellular -growth looks fuzzy 3. mushrooms: basidiomycota
A 0.1 ml sample of a log phase culture contains 10,000 bacterial cells/ml. It is added to 9.9 ml of fresh culture medium broth. Assume a generation time of 30 minutes, and no limiting nutrients. How many bacteria will be present in the entire broth culture after five hours? A) 3.2 × 104 B) 5.0 × 105 C) 1.02 × 106 D) 6.0 × 106 E) 2.56 × 107
1.02 × 106
B) Pseudomonas.
10) The genus of bacteria that are particularly problematic in hospital settings due to their ability to grow in solutions with minute traces of unusual carbon sources is A) Staphylococcus. B) Pseudomonas. C) Vibrio. D) Campylobacter. E) Legionella.
Rotavirus continued: Billions of virus particles/gm of stool shed during peak infection. Infectious dose is <______________. Incubation ___________ Children ______________ have most severe disease Adults are often __________ _______________ continues after symptoms are gone Rotavirus induces cholera type _________ Evidence that a viral protein of Rotavirus acts as an _____________ (like cholera toxin) Rotavirus has a vaccine-______________, recommended as part of childhood immunizations.
100 particles 1 to 3 days 3 to 36 months asymptomatic Viral shedding diarrhea enterotoxin attentuated viral vaccine
how many species of fungi are characterized? how many are medically important? how many are responsible for more than 90% of the fungal infections in humans and animals?
100,000 400 <50
E) Listeria monocytogenes
11) Which of the following can survive in phagocytic cells and grows in refrigeration temperatures? A) Borrelia burgdorferi B) Mycoplasma hominis C) Mycobacterium leprae D) Clostridium botulinum E) Listeria monocytogenes
A) Treponema
12) Which of the following bacteria is gram-negative? A) Treponema B) Corynebacterium C) Bacillus D) Staphylococcus E) Mycobacterium
C) chemoautotrophic bacteria - fix atmospheric nitrogen
14) Which of the following pairs is mismatched? A) dissimilatory sulfate-reducing bacteria - produce H2S B) archaea - extremophiles C) chemoautotrophic bacteria - fix atmospheric nitrogen D) actinomycetes - reproduce by fragmentation E) Cytophaga - a gliding, nonfruiting bacterium
C) require an arthropod for transmission.
15) Rickettsias differ from chlamydias in that rickettsias A) are gram-negative. B) are intracellular parasites. C) require an arthropod for transmission. D) form elementary bodies. E) are enterics.
C) a chemoautotroph.
17) You have isolated a bacterium that grows in a medium containing only inorganic nutrients. Ammonia is oxidized to a nitrate ion. This bacterium is A) gram-negative. B) using anaerobic respiration. C) a chemoautotroph. D) a photoautotroph. E) a photoheterotroph.
C) Streptococcus
18) Which of the following bacteria is gram-positive? A) Pseudomonas B) Salmonella C) Streptococcus D) Bacteroides E) Rickettsia
A) proteobacteria.
19) Escherichia coli belongs to the A) proteobacteria. B) gram-positive bacteria. C) green sulfur bacteria. D) spirochetes. E) actinomycetes.
when did antimicrobial chemotherapy begin? what was the first group of antimicorbials discovered?
1935 sulfonamides
How many ATP molecules are produced in the TCA Cycle for each glucose molecule that enters glycolysis?
2
cell mediated immunity
2 branches T cells- CD8+ killer T cells/cytotoxic T cells- kill virally infected cells CD4+ helper T cells- become effector T cellsactivate macrophages so that they can kill intracellular bacteria CD= Cluster differentiation- things you can find on surface of cells to help tell them apart Numbered into hundreds
TRUE
2) Two distinguishing factors of the epsilonproteobacteria are that they are motile and microaerophilic.
E) spirochaetes
2) What is group "c." in the key shown in Figure 11.1? A) bacteroidetes B) chlamydiae C) fusobacteria D) planctomycetes E) spirochaetes
Enterobacter
2,3-butandediol fermentation bacteria
Acetoin (VP) Test
2,3-butandediol fermentation products
B) Escherichia
20) Which one of the following bacteria does NOT belong with the others? A) Bacillus B) Escherichia C) Lactobacillus D) Staphylococcus E) Streptococcus
E) It is found in soil and water.
21) Which of the following statements about the causative agent of Rocky Mountain spotted fever is FALSE? A) It is an intracellular parasite. B) It is transmitted by ticks. C) It is in the genus Rickettsia. D) It is gram-negative. E) It is found in soil and water.
C) electron donor for CO2 reduction.
22) A primary difference between cyanobacteria and purple and green phototrophic bacteria is A) energy source. B) cell wall type. C) electron donor for CO2 reduction. D) cell type. E) color.
E) Salmonella
23) Which one of the following bacteria does NOT belong with the other betaproteobacteria? A) Bordetella B) Burkholderia C) Neisseria D) Acidithiobacillus E) Salmonella
A) Streptococcus
24) Which of the following bacteria are responsible for more infections and more different kinds of infections? A) Streptococcus B) Staphylococcus C) Salmonella D) Pseudomonas E) Neisseria
A) uses H2S for an energy source.
25) Both Beggiatoa and the purple sulfur bacteria use H2S. These bacteria differ in that Beggiatoa A) uses H2S for an energy source. B) uses H2S for a carbon source. C) uses light energy. D) can photosynthesize. E) is gram negative.
B) electron donors to reduce CO2.
26) The nonsulfur photosynthetic bacteria use organic compounds as A) carbon and energy sources. B) electron donors to reduce CO2. C) oxygen sources. D) electron acceptors. E) carbon and energy sources, and as electron donors to reduce CO2.
D) Listeria
29) All of the following bacteria are gram-positive. Which does NOT belong with the others? A) Actinomyces B) Gardnerella C) Corynebacterium D) Listeria E) Mycobacterium
3:4 attenuator stem loop vs 2:3
2:3: stops 3:4 loop formation and allows transcription 3:4: stops transcription
extracellular killing by leukocytes
3 types: eosinophils, natural killer, neutrophils
You are studying a cell with 20% of its DNA composed of T nucleotides. What percentage of the nucleotides are C?
30
B) gram-negative facultatively anaerobic rods.
30) Salmonella, Shigella, Yersinia, and Serratia are all A) gram negative aerobes. B) gram-negative facultatively anaerobic rods. C) gram-positive aerobic cocci. D) fermentative. E) endospore-forming bacteria.
B) possesses an axial filament.
32) Borrelia is classified as a spirochete because it A) is aerobic. B) possesses an axial filament. C) is a rod. D) is a pathogen. E) is transmitted by ticks.
A) make antibiotics.
33) Streptomyces are important because they A) make antibiotics. B) produce conidia. C) are implicated in acne. D) are strict aerobes. E) fix nitrogen.
A) Gram stain.
34) You have isolated and grown a pure culture of a prokaryotic cell type. The first step in identification is a(n) A) Gram stain. B) lactose fermentation test. C) endospore stain. D) flagella stain. E) DNA fingerprint.
what is the ideal temperature growth for fungi in humans?
35 C to 37 C
B) lack a membrane-bounded nucleus.
35) Actinomycetes differ from fungi in that actinomycetes A) are chemoheterotrophs. B) lack a membrane-bounded nucleus. C) require light. D) are decomposers. E) cause disease.
D) bacillales
36) You have isolated an aerobic gram-positive, endospore-forming bacterium that grows well on nutrient agar. To which of the following groups does it most likely belong? A) phototrophic bacteria B) gammaproteobacteria C) deltaproteobacteria D) bacillales E) The answer cannot be determined based on the information provided.
E) Pseudomonas - gram-positive
37) Which of the following pairs is mismatched? A) spirochete - axial filament B) spirilum - aerobic, helical bacteria C) enterics - gram-negative D) mycobacteria - acid-fast E) Pseudomonas - gram-positive
During glycolysis, a single 6-carbon molecule of glucose is converted to two 3-carbon pyruvate molecules. During the later steps in this process, how many molecules of ATP are generated?
4
why do some people still get the flu even when they get the flu shot
4 reasons 1. someone could have another respiratory virus that causes flu-like symptoms 2. someone could have been exposed to influenza viruses shortly before getting vaccinated 3. someone may have been exposed to a flu virus very different from viruses in vaccine 4.
A) requires X and V factors
4) Which of the following is NOT a characteristic of Neisseria? A) requires X and V factors B) cocci C) gram-negative D) oxidase-positive E) Some species are human pathogens.
D) spirochetes
40) All of the following bacteria are motile. Which does NOT have flagella? A) Escherichia B) Spirillum C) Pseudomonas D) spirochetes E) Salmonella
E) are found in gingival crevices and in the intestinal tract.
41) Bacteroides A) are found in gingival crevices. B) are found in the intestinal tract. C) are strict aerobes. D) are strict aerobes and found in gingival crevices. E) are found in gingival crevices and in the intestinal tract.
A) have a developmental cycle.
42) Chlamydia differ from most other bacteria in that they A) have a developmental cycle. B) lack a cell wall. C) are acid-fast. D) produce endospores. E) are photosynthetic.
A) elementary body - Escherichia
43) Which of the following pairs is NOT correctly matched? A) elementary body - Escherichia B) endospore - Bacillus C) endospore - Clostridium D) heterocyst - cyanobacteria E) myxospore - gliding bacteria
E) its rRNA sequence is similar to that of Neisseria.
44) Burkholderia was reclassified from the gammaproteobacteria to the betaproteobacteria because A) it grows in disinfectants. B) it is a gram-negative rod. C) it causes infections in cystic fibrosis patients. D) it causes melioidosis. E) its rRNA sequence is similar to that of Neisseria.
E) Wolbachia.
45) A biological control method to reduce the reproductive success of mosquitoes involves the use of A) Acinetobacter. B) Gemmata. C) Neisseria. D) Pelagibacter. E) Wolbachia.
Structure of RNA polymerase
5 different subunits: (2) alpha, beta, beta prime, omega, and omega
C) cell arrangement.
5) Staphylococcus and Streptococcus can usually be differentiated by microscope examination because of A) cell shape. B) Gram stain reaction. C) cell arrangement. D) endospore formation. E) acid-fast reaction.
Consider the figure below. Which statement is TRUE?
5-bromouracil may be incorporated into a newly synthesized DNA strand in place of a thymine nucleobase
If a 75 base-pair fragment of DNA has 25 cytosines in it, how many adenines would you expect it to have?
50
A microbiologist inoculates a flask of broth to a concentration of 100 bacterial cells per ml. The generation time of the species is 1 hour, and there is no lag phase. How long will it be before the culture contains more than 6,000 cells per ml? A) 12 hours B) 6 hours C) 2 hours D) 4 hours E) 10 hours
6 hours
C) Bordetella
6) Which of the following genera can be described as a non-motile aerobic gram negative rod? A) Escherichia B) Staphylococcus C) Bordetella D) Treponema E) Neisseria
blood is made up of how much plasma and how much formed elements?
60% plasma 40% formed elements (RBC, platelets, WBC)
what kind of ribosomes do fungi have? what kind of ribosomes do bacteria have?
60S / 40S subunit ribosome: fungi 50S/30S: bacteria
How many types of viruses are there according to the Baltimore Classification system?
7
TRUE
7) The majority of bacterial species on Earth have not been successfully cultivated.
A) Bacillus subtilis
7) Which of the following do you expect to be MOST resistant to high temperatures? A) Bacillus subtilis B) Escherichia coli C) Neisseria gonorrhoeae D) Staphylococcus aureus E) Streptococcus pyogenes
describe structure of influenza
8 segments of linear negative strand RNA
FALSE
8) Photosynthetic organisms always produce oxygen gas as a metabolic byproduct.
E) Campylobacter
8) Which of the following is NOT an enteric? A) Salmonella B) Shigella C) Escherichia D) Enterobacter E) Campylobacter
TRUE
9) Currently, no members of Archaea have been linked to human disease.
D) easily observed with brightfield microscopy
9) Which of the following is NOT a characteristic of spirochetes? A) possess an axial filament B) gram-negative C) helical shape D) easily observed with brightfield microscopy E) found in the human oral cavity
R naught (R sub 0)
= basic reproductive rate (if you had a completely susceptible population) How many new cases of a disease do you expect to see if one person has it Measure of the potential for transmission of a disease Mean number of secondary cases occurring in a susceptible population upon exposure to an infected individual Whooping cough: 12-17 Measles: 12-18 Polio: 5-7 Mumps: 3-5 Ebola: 1-2
FALSE
A bacterial cell has replicated its plasmid, and when this cell divides into 2 daughter cells, each cell receives one copy of the plasmid. This is an example of horizontal gene transfer
False
A bacterial cell has replicated its plasmid, and when this cell divides into daughter cells, each cell receives one copy of the plasmid. This is an example of horizontal gene transfer
Generalized transduction
A bacteriophage transfers a random fragment of DNA of the previous host to the current host. This is an example of
facultative anaerobe
A bacterium is inoculated into a tube of thioglycollate and incubated. After incubation, turbidity appears throughout, top to bottom, with the greatest turbidity at the very top. This bacterium would be called a(n)
THERE WAS NO SULFUR COMPOUND TO THE MEDIUM, THAT COULD BE USED AS AN ELECTRON DONOR
A bacterium that you isolated from pond water appears to use light for energy. Based on this information, you inculcate the organism into fresh media, infused with lots of carbon dioxide. Even after incubation at the correct temperature (of pond water), the organism is not growing. You best explanation of what might happened is
fever
A body temperature over 37 C Pyrogens (can be something released by your immune system can be parts of microbial cells) trigger the hypothalamus to increase the body's core temperature Various types of pyrogens Bacterial toxins Cytoplasmic contents of bacteria Antibody-antigen complexes
Mutagen
A chemical or physical agent that interacts with DNA and causes a mutation.
Clavulanic acid
A chemical that inhibits beta-lactamase enzymes is
MIC (minimum inhibitory concentration test)
A clinical microbiologist makes serial dilutions of several antimicrobials in broth, and then incubates each drug dilution series with a standard amount of a patient's isolated pathogen. What is this microbiologist setting up?
True
A closed culture system is used to determine a population growth curve
selective toxicity
A drug that kills harmful microbes without damaging the host Most things if you take enough of are toxic- water Therapeutic index- higher number better Ratio of toxic dose to therapeutic dose Want therapeutic dose to be tiny fraction of toxic dose
innate immunity
A form of defense common to all animals that is active immediately upon exposure to pathogens and that is the same whether or not the pathogen has been encountered previously. general signs of infection
Deletion and insertion
A frameshift is caused by ______ mutations.
cofactor
A holoenzyme is a combination of a protein and one or more substances called
This is a silent mutation
A mutation has occurred during DNA replication while the cell was preparing to divide. As a result of this, the codon ACU of mRNA has now become ACC. Interestingly, there is no change to the protein being made. Why not?
temperate phage
A phage that is capable of reproducing by either the lytic or lysogenic cycle.
aseptic technique
A procedure performed under sterile conditions.
Disinfection
A process that eliminates many or all microorganisms, with the exception of bacteria spores, from inanimate objects
If an mRNA is degraded rapidly by an RNase, it may lose its stop codon even while it is still being translated. This might prevent the ribosome being released. Which of the following allows this problem to be solved?
A tmRNA molecule has parts that bind to the peptide and to the ribosome as a stop codon to allow it to complete the process of translation.
41) Into which group would you place a multicellular organism that has a mouth and lives inside the human liver? A) Animalia B) Fungi C) Plantae D) Firmicutes (gram-positive bacteria) E) Proteobacteria (gram-negative bacteria)
A) Animalia
39) Use the dichotomous key in Table 10.2 to identify a gram-negative cell that ferments lactose and uses citric acid as its sole carbon source. A) Citrobacter B) Escherichia C) Lactobacillus D) Pseudomonas E) Staphylococcus
A) Citrobacter
40) Use the dichotomous key in Table 10.2 to identify a gram-negative coccus. A) Neisseria B) Pseudomonas C) Staphylococcus D) Streptococcus E) Micrococcus
A) Neisseria
18) ________ are a diverse group of eukaryotic organisms that are similar in rRNA sequences, but quite different from each other in motility types and ecology. They have been used previously as a "catch-all" for organisms that couldn't be easily classified into other groups. A) Protists B) Fungi C) Plants D) Methanogens
A) Protists
22) Which of the following best defines a strain in microbiological terms? A) a pure culture that is not totally identical to other cultures of the same species B) a group of organisms with a limited geographical distribution C) a mixed population of cells,genetically distinct, but with highly similar phenotypic characteristics D) groups of cells all derived from and identical to a single parent species E) same as a species
A) a pure culture that is not totally identical to other cultures of the same species
49) Fatty acid methyl ester analysis is commonly used A) in bacterial identification. B) in DNA sequencing reactions. C) in serological identification methods. D) in DNA fingerprinting.
A) in bacterial identification.
Which regions of the gene (or segment of DNA) shown here encodes the amino acid sequence of a protein?
A,C,E (exon)
Which of the following would be possible in a correctly constructed double-stranded DNA molecule?
A-T, A-T, T-A, C-G, G-C
which of the following substances is least toxic to humans
A: hydrogen peroxide (not carbolic acid, glutaraldehyde, or formalin)
In the figure, what are the correct terms for the regions labeled "A" and "B"?
A: promoter B: terminator
During the electron transport chain, ATP will be made from
ADP + Pi
T cell activation
APC- antigen presenting cell, presenting molecules on both MHC class 1 and 2, class 1= naïve CD8 T cells, class 2= CD4 T cell Become activated, clonal expansion, differentiate into effector cells or memory cells and effector cells go out and do their jobs- CD4 activates macrophages or B cells, CD8 killing target cells like virally infected cells- can also play role in macrophage activation
The Calvin Cycle uses ______ and ______, produced in the light reactions of photosynthesis, to drive the fixation of carbon dioxide.
ATP and NADPH
False
ATP is composed of deoxyribose, adenine, and three phosphate groups.
False
ATP molecules are catalysts that lower the activation energy needed to initiate a reaction
True
ATP synthase is a complex enzyme needed for oxidative phosphorylation
Consider how an aerobically respiring bacterial cell uses glycolysis, the TCA cycle, and oxidative phosphorylation to break apart and oxidize glucose. What are the three main benefits these central metabolic pathways yield to the cell?
ATP, reduced electron carriers, and precursor metabolites
If the transcript shown here is translated, what is the codon that corresponds to the second amino acid in the resulting protein? 5' GCUGAUGAUCCGCGUZGGUGCU 3'
AUC
clostridium
Acetone fermentation bacteria
acetone, isopropanol
Acetone fermentation chemicals
nail polish remover, rubbing alcohol
Acetone fermentation products
In-Use test
Actually use disinfectant the way you would use it Take object you have contaminated or that you would normally expect to have some contamination, take swabs off specific area, measure off quadrants, apply antimicrobials in other quadrants, inoculate into growth media, media monitored for growth (quantifying)
epidemiology and public health
Address infectious disease and chronic disease Responsible for health of public- ensure we have a coordinated effort to deal with outbreaks Provide education- infectious diseases, sexually transmitted diseases, overall healthful choices- exercise and diet guidelines Work to limit disease transmission by monitoring food and water safety- restaurant inspections Work to control reservoir and vector populations- vectors = mosquitos Provide info about vaccines and guidelines
Glycolosis, Krebs cycle, electron transport chain
Aerobic Respiration: Pathways
fungus
After using jelly on a sandwich, you close the jar and place it on a room temperature shelf instead of in the refrigerator. When you open the jar several weeks later, you notice microbial growth on the surface. What type of organism is likely to grow in this environment?
X-rays
Agents that can denature microbial proteins include all of the following except
TRUE
Alcohols are more effective at inactivating enveloped viruses than naked viruses
Side effects
All drugs have them Toxicity Kidneys, liver, or nerves Special concerns in pregnant women- some can pass through placenta Allergies Immune system responds to drug Rare but may be life threatening- particularly when administered through IV, could just be a rash with oral Disruption of normal microbiota- most common, leads to GI symptoms, nausea, vommiting, diarrhea, many antibiotics are broad spectrum and kill off bacteria like E.coli, allows others to proliferate- C Diff can occur in rare cases, can eventually become life threatening, normal microbiota not there to compete with it, causes severe diarrhea Yeast infections in women very common when on antibiotics
Iodine
All of the following act as surfactants except
Iodophor
All of the following are alkylating control agents except
it occurs on a ribosome in the cytoplasm.
All of the following pertain to transcription except
Adjuvants licensed for human use in the US
Alum- slows processing and degradation of antigen so that it will be displayed more readily on antigen presenting cells (aluminum phosphate) MF59- influenza vaccine, increases local cytokine and chemokine- cell signaling molecules of immune system AS04- signals through toll-like receptors, increases local cytokines and chemokine and cell recruitment of dendritic cells- main professional antigen presenting cells AS03- works in similar way, increases cytokines, recruits granulocytes and monocytes to the area, flu vaccine Virosomes- look like liposomes, function like a viral envelope to try and get viral DNA into a cell like a real virus so that is presented more like an actual infection
attach to the 30s ribosomal subunit and disrupt protein synthesis
Aminoglycosides
drugs that act against protein synthesis include
Aminoglycosides
Most appropriate to treat a funal infection?
Amphotericin B
A beta-lactam ring
Ampicillin, amoxicillin, mezlocillin, and penicillin G all have
False
An example of gene therapy is the insertion of the gene for human growth hormone into E. Coli cells
Iron
An important mineral ion found in the cytochrome pigments of cellular respiration is
Magnesium
An important mineral ion that is a component of chlorophyll and serves as a stabilizer of membranes and ribosomes is
microbial growth
An increase in the number of cells, not the cell size
virion/ virus particle
An inert particle that does not carry out any metabolism or energy conversion
facultative anaerobes
An organism that can exist in both oxygen and oxygen-free environments is a(n) _________
obligate anaerobe
An organism that cannot tolerate an oxygen environment is a(n)
facultative psychrophile.
An organism that grows slowly in the cold but has an optimum growth temperature of 32 degrees is called a(n)
Photoautotroph
An organism that uses CO2 for its carbon needs and sunlight for its energy needs would be called a
photoautotroph
An organism that uses CO2 for its carbon needs and sunlight for its energy needs would be called a
cytochrome C oxidase
An oxidase detection test can be used to identify certain bacteria because they are missing or lack expression of
is eukaryotic
An unidentified cell was found to contain introns and exons. It also expresses DNA polymerase and RNA polymerase. Although it exhibits a promoter region, it has no operons. You conclude that this cell
Condensation
Anabolic reactions that involve ligases and release water molecules when bonds are formed are called ______ reactions.
precursors, larger building blocks, macromolecules
Anabolism= ____ -> _____ -> ______ ->
True
Anaerobes can be cultured in a CO2 environment
2-36
Anaerobic Respiration: Amount of ATP
Glycolosis, Krebs cycle, electron transport chain
Anaerobic Respiration: Pathways
helminth, protozoa, bacteria
Anaerobic Respiration: Which organisms?
External inorganic or organic molecule (NOT O2) (ex NO3, SO4, CO3)
Anaerobic Respiration: final e- acceptor
No
Anaerobic Respiration: is O2 required
all of the above are correct (larger fragments moving slowly and remaining closer to the wells, DNA having an overall negative charge and moving to the positive pole, DNA fragments being stained so that they can be seen, application of an electric current through the gel causing DNA fragments to migrate)
Analysis of DNA fragments in gel electrophoresis is based on
inhibition of metabolic pathways
Antimetabolits- block metabolic pathways Quinolones- include antiparasitic drugs, particularly used for malaria as preventative and treatment Sulfonamides- can be used as antibacterial/protozoal/fungal- interfer with folate synthesis Atovaquone- antifungal/protozoal- interferes with electron transport Amantadine and Rimantadine- antiviral- interfer with virus uncoating, so cant establish infection, neutral acidic environment in phagolysosome that would result in uncoating that would reveal genetic info
True
Antimicrobial drugs that inhibit folic acid synthesis work with no side effects because mammals get their folic acid from their diet
.broad-spectrum drugs
Antimicrobials effective against a wide variety of microbial types are termed
Biotechnology
Any use of an organism's biochemical processes to create a product is referred to as
TURBIDITY READINGS FROM A SPECTROPHOTOMETER, THE INCREASE IN BIOMASS WILL DIRECTLY VARY WITH THE TURBIDITY OF THE CULTURE.
As described in "A Note About Bacterial Reproduction"- and the "Culture Bias' the organism of Epulopiscium does not divide by binary fission. Rather, each cell increases in size and divides to produce multiple daughter cells that are held within the original cell well. After lysis, those daughters are released to repeat the process. Assuming Epulopiscium could be grown in pure culture in the laboratory in broth and on solid media (it currently cannot), which method would be best for measuring the increase in biomass during growth?
Hydrogen Ions
As the electron transport carriers shuttle electrons, they actively pump _____ into the outer membrane compartment, setting up a concentration gradient called the proton motive force
Why are autoimmune diseases more prevalent in older individuals
As you get older, thymus shrinks, do not have process happening as well, more autoimmune diesases in older people
asymmetrical virions
Asymmetric capsid or core particle Segments of nucleic acids coated with nucleocapsid proteins accessory proteins
Prevention of virus attachment
Attachment antagonists Block viral attachment Often analogs of attachment or receptor proteins HIV drug- muravaroc- binds to ccr5 on host cells to prevent attachment of HIV Neuraminidase inhibitors (Oseltamivir-Tamiflu) Prevents flu virus from attaching to or exiting host cells, can help reduce duration if started early enough
somatic hypermutation
B cells (produce antibodies), if they are exposed to a particular antigen for a prolonged period of time or if they have repeated exposures like with vaccinations and booster shots or repeated infections naturally Results in higher affinity antibody response- antibodies that bind better to invader
antigen recognition
B cells recognize native antigens directly (proteins, lipids, sugars) B cell receptor is antibody on surface of B cell Recognize w/o processing- protein antigens, lipids, sugars T cells recognize peptide antigens processed and bound to MHC Combination of self (MHC) (major histocompatibility complex) and non-self (antigen) required for activation Phagocyte has to chew up bacterium and present tiny piece of it on MHC T cell recognizes combination of MHC and peptide and bind to the macrophage, initiating a series of immune events Many B cells require help from T cells for initial activation (especially ones that recognize protein antigens) only produce very limited types of antibodies without help for helper T cells Professional antigen presenting cell- any cell that can activate a naive T cell (often dendritic cells), can chew up antigen and present it and provide secondary signals, macrophages can sometimes do it, dendritic best
Consider the biochemical pathway: A → B → C Enzyme 1 catalyzes A → B Enzyme 2 catalyzes B → C If enzyme 2 is inactive, which of the following compounds will accumulate?
B only
33) In Table 10.1, which feature(s) is (are) found only in prokaryotes? A) 1, 2, 3 B) 4, 6 C) 2 D) 1 E) 2, 4, 5
B) 4, 6
37) You discovered a unicellular organism that lacks a nucleus and peptidoglycan. You suspect the organism is in the group A) Animalia. B) Archaea. C) Bacteria. D) Fungi. E) Plantae.
B) Archaea
36) Into which group would you place a photosynthetic cell that lacks a nucleus? A) Animalia B) Bacteria C) Fungi D) Plantae E) Protista
B) Bacteria
38) Into which group would you place a unicellular organism that has 70S ribosomes and a peptidoglycan cell wall? A) Animalia B) Bacteria C) Fungi D) Plantae E) Protist
B) Bacteria
43) In the cladogram shown in Figure 10.4, which two organisms are most closely related? A) Streptomyces and Micrococcus B) Micrococcus and Mycobacterium C) Mycobacterium and Lactobacillus D) Streptomyces and Lactobacillus E) Streptomyces and Mycobacterium
B) Micrococcus and Mycobacterium
48) In a direct ELISA test, the method is determining if ________ is/are present in the patient's sample by attempting to bind a labeled antibody to it. A) antibodies against a pathogen found in a patient's blood B) an antigen from a particular pathogen C) a bacteriophage that can infect a particular bacterial strain D) a known sequence of DNA from a pathogen
B) an antigen from a particular pathogen
23) Serological testing is based on the fact that A) all bacteria have the same antigens. B) antibodies react specifically with an antigen. C) the human body makes antibodies against bacteria. D) antibodies cause the formation of antigens. E) bacteria clump together when mixed with any antibodies.
B) antibodies react specifically with an antigen
31) In Figure 10.2, which figure shows the most closely related organisms? A) a B) b C) c D) d E) e
B) b
3) If two organisms have similar rRNA sequences, you can conclude that they A) live in the same place. B) evolved from a common ancestor. C) will have different G-C ratios. D) will both ferment lactose. E) mated with each other.
B) evolved from a common ancestor.
19) In the scientific name Enterobacter aerogenes, Enterobacter is the A) specific epithet. B) genus. C) family. D) order. E) kingdom.
B) genus
endospores of which organism can be used as a biological indicator of sterilization
Bacillus stearothermophilus
become dehydrated due to the loss of water
Bacteria living in a freshwater stream that are transferred to ocean water would ________.
Humans suffering from infections with antibiotic resistant bacteria can be treated with phages, which will infect and lyse the bacterial cells, leaving human cells unaffected.
Bacteriophages selectively infect bacterial cells. How might they be used as a therapeutic treatment in humans?
Hydrogen
Base pairs in DNA are held together by ______ bonds.
WHY DO FECAL-ORAL PATHOGENS UNLIKELY TO CAUSE OUTBREAK?
Because Humans are the only reservoir. One infected person will not infect thousands of people.
Why is OPV (oral polio vaccine) used for global campaigns?
Because of its: 1. Immunity in GI tract 2. Easy to administer
All of the choices are correct
Below is a metabolic pathway having 3 chemical reactions and 3 enzymes. Enzyme 1 has 2 binding sites--1 for the substrate A and another for the end product D. As the pathway proceeds, the end product in higher quantities will react with enzyme 1, blocking the enzyme's binding to the substrate. Which statement is true about this pathway? enz1 enz2 enz3 Substrate A --> B --> C --> D end product This is a case of noncompetitive inhibition. As a result of the inhibition of the enzyme, there will eventually be less substrate converted to the end product D. Enzyme 1 has an active site and a regulatory site. All of the choices are correct.
________ are complex communities of various types of microbes that adhere to surfaces. A) Aggregates B) Colonies C) Isolates D) Biofilms E) Media
Biofilms
harder to kill
Biofilms are dangerous in the medical community because they are ______ ___ ______.
Inhibition of nucleic acid synthesis
Block DNA replication or mRNA transcription Often affect both prokaryotes and eukaryotes Limited use- transcription very similar in pro and euk Include Quinolones Ciprofloxacin- can have a lot of side effects, Achilles tendon rupture, strong, works well against certain bacterial infections Rifamycin Targets bacterial RNAP (RNA polymerase), a little more specific Some antiviral agents- most HIV drugs Nucleotide/nucleoside analogs (acyclovir, AZT-NRTI) NNRTI- non-nucleoside reverse transcriptase inhibitor In most HIV treatment use combo of nucleoside analogs and NRTI, when analog is incorporated into DNA or RNA makes it non functional NNRTI- inhibit the enzyme reverse transcriptase, HIV is a retrovirus so brings its own reverse transcriptase when it causes infection, essential when going from the RNA genome of HIV to DNA copy so that it can cause infection Either way inhibits spread
What steps could be taken to reduce the spread of water-borne illnesses such as cholera?
Boiling advisory, filter water
Broad spectrum vs narrow spectrum
Broad- effective against wide variety of bacteria (ex: both gram pos and gram neg or large variety of just gram neg) Narrow- only effective against a couple types of bacteria, great if you know exactly what is causing infection bc will specifically target what it is youre trying to kill, less likely to kill normal flora
True
Building block molecules for biosynthetic pathways come from the cell's catabolic pathways and from the environment.
24) Phage typing is based on the fact that A) bacteria are destroyed by viruses. B) viruses cause disease. C) bacterial viruses attack only members of a specific species. D) Staphylococcus causes infections. E) phages and bacteria are related.
C) bacterial viruses attack only members of a specific species.
________ is a start codon, while _______ is a stop codon A. CAU; UAC B. CAA; UUC C. AUG; UGA D. UUU; AAA
C. AUG; UGA
You are studying the metabolism of the phototrophic green sulfur bacterium Cholorbaculum tepidum and realize that it is running a reversed TCA Cycle! How do you explain this observation?
C. tepidum is using reversed TCA cycle to fix carbon dioxide
which enzyme is a crucial stem in complement activation?
C3 convertase
CD4 T cells bind to which MHC? CD8 cells bind to which MHC?
CD4: MHC Class II -exogenous, killing through phagosome -only found on some cells CD8: MHC Class I -endogenous, killed via transporter associated with antigen processing -found on all nucleated cells
what are the two categories of Cd4 cells? what are the 2 categories of Cd8 cells?
CD4: Th1 and Th2 cells CD8: cytotoxic (Tc) and suppressor T cells (Ts)
Which of the following statements is CORRECT regarding Figure 6.1? A) Cells are actively growing only during the stage represented by B. B) No cells are reproducing during the stage represented by D. C) Cells are most susceptible to antibiotics during the stage represented by A. D) Cells are alive but not reproducing during the stage represented by A. E) No new cells are being produced during the stage represented by C.
Cells are alive but not reproducing during the stage represented by A.
hypertonic
Characteristics of a solution having a higher concentration of solutes than another
hypotonic
Characteristics of a solution having a lower concentration of solutes than another
higher [ ] attractant and methyl accepting chemotaxis proteins
CheA inactivated and tumbling suppressed and prolongs run
lower [ ] attractant and methyl accepting chemotaxis proteins
CheY=P made again and organism will tumble
chemical mutagens
Chemicals that cause genetic mutations. Ex, pesticides, tobacco smoke, environmental pollutants
False
Chlorine compounds remain stable and effective in the presence of excess organic matter
False
Ciprofloxacin is used to treat viral respiratory infections
Use-dilution test
Classic way to test antimicrobials that are chemicals Bunch of metal cylinders, dip into broth cultures of bacteria, immerse in disinfectant testing for 10 minutes, place into tube of medium for 48 hours and see if it grows Most effective agent entirely prevents growth at highest dilution (lowest concentration) Test to see if a particular disinfectant works and at what concentration it works Dilution series that you test Depends on organism Limitations with test- not necessarily reflective of reality, whether or not it will work in house or kitchen, because just testing on metal disks/cylinders, not all surfaces are metal
Some enzymes require a cofactor or a coenzyme in order to be active. What is the difference between cofactors and coenzymes?
Cofactors are non-protein components that assist enzymes and are typically trace elements; conenzymes are organic cofactors that loosely carry molecules or electrons.
in cold temperatures, the energy of activation is not sufficient to drive chemical reactions regardless of the presence of enzymes, whereas excessive heat denatures enzymes and/or incinerates the cell causing irreparable damage.
Cold temperatures are considered microbiostatic, whereas excessive heat is considered microbicidal. This is due to the fact that
function of alpha subunit of RNA pol
Communicates with regulatory proteins that bind DNA
what does beta hemolysis look like?
Complete digestion of the RBC & Hb clear zone of hemolysis
blood
Composed of cells and portions of cells (platelets) within a fluid called plasma Plasma is mostly water Serum is plasma without clotting factors contains complement proteins and antibodies
Disruption of cytoplasmic membranes
Contents of cell leak out Commonly used for Antifungals Amphotericin B in class of polyenes is standard antifungal- attaches to ergosterol found in fungal membranes- used to treat majority of fungal infections, only problem is can be toxic, ergosterol is similar to human cholesterol so can cause side effects Amphotericin B attaches to ergosterol creating a pore in membrane where everything can come in and out, cell can't survive Azoles- block ergosterol synthesis Allyamines- block ergosterol synthesis Antibacterial Polymyxin- destroys cell membrane of gram negative cells, effective Antiparasitic drugs Praziquantel and ivermectin- used to treat worm infections, disrupts cell membrane, changes permeability of membrane so worm will end up dying
False
Continued widespread use of the phenolic compound triclosan is advantageous in that it is important to remove as many organisms as possible from our hands and there is little risk of resistant organisms evolving.
34) Into which group would you place a multicellular heterotroph with chitin cell walls? A) Animalia B) Archaea C) Bacteria D) Fungi E) Plantae
D) Fungi
1) Which of the following statements about archaea is FALSE? A) They are prokaryotes. B) They lack peptidoglycan in their cell walls. C) Some are thermoacidophiles; others are extreme halophiles. D) They evolved before bacteria. E) Some produce methane from carbon dioxide and hydrogen.
D) They evolved before bacteria.
5) Which of the following statements about members of the Kingdom Plantae is FALSE? A) They are multicellular. B) They are composed of eukaryotic cells. C) They undergo photosynthesis. D) They use organic carbon sources. E) They synthesize organic molecules.
D) They use organic carbon sources.
13) Which of the following statements is a reason for NOT classifying viruses in one of the three domains of life (Bacteria, Archaea, Eukarya) rather than in a fourth separate domain? A) Some viruses can incorporate their genome into a host's genome. B) Viruses direct anabolic pathways of host cells. C) Viruses are obligate parasites. D) Viruses are not composed of cells. E) All of the answers are correct.
D) Viruses are not composed of cells.
10) A biochemical test, in the microbiology world, is used to determine A) staining characteristics. B) amino acid sequences of enzymes. C) nucleic acid-base composition of DNA sequences. D) capability of a microbe to perform a specific enzymatic activity. E) All of the answers are correct.
D) capability of a microbe to perform a specific enzymatic activity
21) Bacteria and Archaea are similar in which of the following? A) peptidoglycan cell walls B) methionine as the start signal for protein synthesis C) sensitivity to antibiotics D) considered prokaryotic cells E) plasma membrane ester linkage
D) considered prokaryotic cells
16) In Figure 10.1, species "c." is most closely related to which of the following? A) a B) b C) c D) d E) e
D) d
50) Flow cytometry, where a cell is passed through a light source such as a laser beam, can directly indicate all EXCEPT which one of the following about a cell? A) size B) shape C) density D) identity
D) identity
8) A bacterial species differs from a species of eukaryotic organisms in that a bacterial species A) does not breed with other species. B) has a limited geographical distribution. C) can be distinguished from other bacterial species. D) is a population of cells with similar characteristics. E) breeds with its own species.
D) is a population of cells with similar characteristics.
28) All of the following statements are reasons why fluorescent in situ hybridization (FISH) has become a valuable tool for environmental microbiologists EXCEPT A) it allows for detection of uncultured microbes. B) it demonstrates the diversity of microbes in an environment. C) it allows observation of microbes in their natural environment in association with other microbes. D) it allows one to obtain pure cultures of microbes. E) All of the answers are correct.
D) it allows one to obtain pure cultures of microbes
ENTAMOEBA HYSTOLYTICA —> Amebiasis
DISEASE: Amebiasis or amoebic dysentery FEATURES - Amebozoa (has the ability to alter its shape by forming pseudopods) - small - contaminates water - severe cases, can cause lesions in the GI tract
CYCLOSPORA CAYETANENSIS
DISEASE: Cyclosporiasis FEATURES: - Apicomplexa - related to plasmodium falciparum - causes watery diarrhea, vomiting, weight loss, muscle aches - self-limiting - can live as oocyst or sporozoite
ASCARIS LUMBROCOIDES (adult roundworm) ***
DISEASES: Ascariasis FEATURE: - adult roundworm (nematode) LIFECYCLE: ‣ Worm secretes fertilized egg —> forms into larvae —> gets into the human host —> larvae will hatch in the intestine —> then it will penetrate the intestinal mucosa —> goes to the lungs (circulatory system)—> worm grows and matures in the lungs —> goes back to the throat —> swallowed back to intestines —> secretes eggs via feces
removes supercoiling ahead of origin
DNA Gyrase
removes primers
DNA Polymerase I
Proofreads new DNA
DNA Polymerase III
phosphate groups have a net negative charge.
DNA fragments can be separated in gel electrophoresis because
True
DNA photolyase, in the presence of visible light, can repair DNA damage due to ultraviolet radiation
True
DNA photolyase, in the presence of visible light, can repair DNA damage due to ultraviolet radiation.
what enzymes are responsible in bacterial division?
DNA polymerase RNA polymerase NO histones involved
Which of the following enzymes is used in methyl mismatch repair, nucleotide excision repair, and base excision repair?
DNA polymerase I
synthesizes new DNA only in the 5' to 3' direction
DNA polymerase III
This means that since the strands are antiparallel, one strand will grow toward the fork as it opens, and the other strand will grow in fragments away from the fork.
DNA polymerase can catalyze a dehydration synthesis reaction only at the 3' carbon of the daughter strand of DNA.
include Taq polymerases and Vent polymerase
DNA polymerases used in PCR
False
DNA replication proceeds in one direction around the bacterial chromosome
90oC
DNA strands can begin to separate at the temperature of
difference between DNA and RNA in Baltimore classification of viruses
DNA: I,II, VII RNA: III,IV,V,VI
difference between DNA and RNA in where it is replicated
DNA: inside nucleus of host cell RNA: first transcribed and then replicated in cytoplasm
difference between DNA and RNA in accuracy in replication
DNA: more accurate RNA: error prone replication
difference between DNA and RNA in stability and mutation rates
DNA: more stable bc lower mutation rate RNA: unstable bc higher mutation rate
difference between DNA and RNA in packaging new genetic information
DNA: newly synthesized viral DNA packed into pre formed capsid RNA: newly synthesized viral RNA not packed in procapsid
True
Denaturing an apoenzyme will destroy the three-dimensional shape of the protein, making it nonfunctional.
how does animal viruses exhibit host and tissue tropism
Depend on virus's ability to interact with cytoplasm or presence of appropriate host cell receptor protein that can bind to viral surface attachment protein
Pasteurization
Destruction of all pathogens and most spoilage microbes in dairy products, fruit juices, beer, an wine. non sterile Flash: 72oC, 15 sec Batch: 66oC, 30 min.
Rotavirus is very stable in: __________ pH 3.5 to 10 (___________) __________-can last on surfaces for days Stable in a wide range of __________ (all of the viruses that cause gastroenteritis in this lecture have these characteristics-they are naked viruses)
Detergents stomach acid Drying Temperatures
acute inflammation
Develops quickly and is short lived Immune cells rush to area so take in microbes and get rid of them Is usually beneficial Important in the second line of defense If skin gets broken, dilation and increased permeability of the blood vessels so that immune cells can squeeze into the area very easily Migration of phagocytes to area Increased tissue repair
chronic inflammation
Develops slowly and lasts a long time Can cause tissue damage Same inflammatory process but happening over months or years Release toxic things Ex rheumatoid arthritis
Osmosis
Diffusion of water through a semipermeable membrane is called
Antimicrobials ideally...
Discriminately kills what you want it to and not your normal flora- selective toxicity Body needs to be able to use Hypoallergenic Easy to take/administer Mass produced to make it Inexpensive, readily available
efficacy
Disk Diffusion Susceptibility test, Minimum inhibitory Concentration (MIC) test, Minimum bactericidal concentration (MBC) test
aerotolerant anaerobes
Do not use aerobic metabolism, they tolerate oxygen by having some of the enzymes that detoxify oxygens poisonous forms
refrigeration and freezing
Don't necessarily kill bacteria but inhibit their growth Decrease microbial metabolism, growth, and reproduction Refrigeration halts growth of most pathogens Example: listeria can grow in refrigerator Organisms vary in susceptibility to freezing Slow freezing more effective Freeze and thaw a bunch kills Also use freezing to preserve bacteria- flash freeze dry ice methanol bath instant
FALSE
Drug toxicity occurs when an antimicrobial drug acts as antigen and stimulates an allergic response
Template
During replication, each parent DNA strand serves as a _____ for synthesis of new DNA strands.
False
During the Calvin cycle, carbon dioxide gas is fixed into a solid, organic form; this is an endergonic process driven by ATP generated from aerobic respiration.
Electron transport system
During which phase of cellular respiration is the majority of ATP formed?
which bacterial organism is most prominently used in genetic studies?
E coli
17) In Figure 10.1, the closest ancestor for both species "a." and species "b." would be which of the following? A) 1 B) 2 C) 3 D) 4 E) 5
E) 5
45) Data collected to date indicate that A) humans and marine mammals cannot be infected by the same pathogens. B) marine mammals do not get infectious diseases. C) new species of bacteria will not be discovered in wild animals. D) marine mammals don't have an immune system. E) None of the answers is correct.
E) None of the answers is correct.
42) Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan wall surrounded by an outer membrane? A) Animalia B) Fungi C) Plantae D) Firmicutes (gram-positive bacteria) E) Proteobacteria (gram-negative bacteria)
E) Proteobacteria (gram-negative bacteria)
27) One of the most popular taxonomic tools is DNA fingerprinting to develop profiles of organisms. These profiles provide direct information about A) enzymatic activities. B) protein composition. C) the presence of specific genes. D) antigenic composition. E) the similarities between nucleotide sequences.
E) the similarities between nucleotide sequences
47) When performing phage typing to identify an unknown bacterium, you must have ________ in your possession. A) DNA that will hybridize to the DNA of the bacterium to be identified B) RNA that will hybridize to the RNA of the bacterium to be identified C) antiserum containing antibodies that will bind to the bacterium to be identified D) fluorescent molecules that will light up when bound to the DNA of the bacterium E) viruses that will specifically infect the bacterium you're trying to identify
E) viruses that will specifically infect the bacterium you're trying to identify
block site where tRNA usually comes in
E, P, and A sites- tetracycline and some other aminoglycosides can block docking site of tRNA, and so if you cant have any tRNA come in, you cannot produce proteins, kills cell Also broad spectrum antibiotic
True
E.Coli is the best host for cloning because it possesses the mechanisms for processing and modifying proteins.
what did david the bubble boy end up dying from?
EBV (epstein Barr Virus)
FADH2 + NADH + 6 O2 -> 6 H20 + 34 ATP
ETC reaction
Are fungi eukaryotes or prokaryotes?
EUKARYOTES has nucleus with nuclear membrane, ER, mitochondria, and secretory apparatus
2
Each FADH2 from the Krebs cycle that enters the electron transport system results in the production of _____ ATP(s)
3
Each NADH that enters the electron transport system results in the production of _____ ATPs
pathogenicity
Each of the following are features of a cloning host except
reverse transcriptases.
Each of the following are features of a cloning vector except
they increase the activation energy of a reaction.
Each of the following are true of enzymes except
a drug being used as a nutrient by the cell.
Each of the following results in drug resistance, except
polymyxins
Each of the following target bacterial ribosomes, except
Inhibition of fungal cell wall synthesis
Echinocandins (newish) Inhibit enzyme that synthesizes glucan Fungal cell walls made of glucan Limited options for antifungals
restriction endonucleases
EcoRI and HindII are
The sporangium; it supports endospore development and then lyses
Endospore-forming bacteria like Bacillus species begin the sporulation process with an asymmetric cell division to produce two cells with different fates. One will differentiate into the endospore, and the other is the sporangium that will ultimately lyse to release the mature endospore. (Review Process Figure 4.24.) During this asymmetric cell division, one of the compartments does not receive an intact copy of the chromosome. Which compartment can function with only part of the genome and why?
Chemoautotrophs
Energy source: Chemicals, Carbon Source: CO2
Chemoheterotrophs
Energy source: Chemicals, Carbon Source: Organic Compounds
Photoautotrophs
Energy source: Light, Carbon Source: CO2
benefits of fever
Enhances the effects of interferons Inhibits growth of some microorganisms May enhance the performance of phagocytes, cells of specific immunity, and the process of tissue repair If an individual lacked many components of the innate immune system, how would this affect their health? Would be susceptible to everything Phagocytic cells Adaptive immune system will not function without innate
Proteins that function as catalysts.
Enzymes are
Induced enzymes
Enzymes that are only produced when substrate is present are termed
how was bacteriophage lambda discovered?
Esther Lederberg performed a genetic cross between 2 strains of E.Coli and mutagenized with ultra violet light the mutant strain formed colonies that were nibbled and plaqued, mutant lost its lambda prophage and was susceptible to infection
All of the choices are correct.
Eukaryotic chromosomes differ from bacterial chromosomes because only eukaryotes have histone proteins chromosomes in a nucleus several to many chromosomes elongated, not circular, chromosomes All of the choices are correct
riboswitch during translation
Excess ligand will bind to riboswitch and stabilize 3D structure that sequesters RBS (burying it) and prevents translation of coding region
occur during aerobic cellular respiration.
Exergonic reactions
True
Exoenzymes from pathogens are called virulence factors.
mass spectrometry in obtaining proteomic data
Experimentally determines exact mass of unknown protein/ peptide fragment and uses mass to identify protein
Physical methods of microbial control
Exposure to extremes of heat or cold- autoclave (heat and pressure), cooking food Desiccation- drying things out, jerky Filtration- best way to ensure getting clean water when hiking Osmotic pressure- salt or sugar to preserve things Radiation- clean instruments, preserve food
4) The highest level in the current taxonomic hierarchy is "Kingdom."
FALSE
6) At this point in time, scientists believe the vast majority of the domain Bacteria have been discovered.
FALSE
7) Once a culture is purified, the next logical step in the process of identifying bacteria is biochemical testing.
FALSE
T or F: Ionization radiation is commonly used to clean skin in preparation for surgery
FALSE
T or F: Sterilization involves using heat to kill pathogens in food products
FALSE
T/F innate and adaptive immunity work independently.
FALSE they work together
T/F? a mutation only affects the genotype of a bacterium.
FALSE also affects the phenotype because bactera ia a haploid (single copy of each gene)
T/F? nucleoid is surrounded by a double walled membrane
FALSE nucleoid has no membrane
HOOK WORMS (adult nematode)
FEATURES: - Adult roundworm (nematode)
SHIGELLA
FEATURES: - gram — SEROTYPES: - S. Dysenteriae - S. Flexneri - S. Boydii - S. Sonnei (majority of US isolates) INFECTIOUS INCOLUM: - 10 cells RESERVOIR: - only humans (no animal reservoir) - thus, unlikely to cause outbreaks. - an infected person will not infect thousands of people DISEASE: - causes severe, bloody diarrhea SHIGELLA VS E.COLI 0157 - Shigella only infects humans vs Ecoli infects cattle (thus people get exposed to this toxin) - Ecoli has shiga toxin from Shigella
HELICOBACTER PYLORI
FEATURES: - gram — - spiral shaped - highly mobile - highly diverse - the only bacterium CAPABLE OF COLONIZING STOMACH; it survives high acidity by producing a lot of urease to neutralize the acid*** - can be detected and treated CLINICAL MANIFESTATIONS:*** - Most infections are asymptomatic - Diseases: 1. Stomach ulcer, duodenal ulcer, or chronic gastritis - due to production of large amnts of urease - pain, bloating, lack of appetite, dark stool, nausea, vomiting 2. Stomach cancer - ulcers in long term lead to cancer (gastric lymphoma) DIAGNOSIS*** - can be detected and treated - non is fool-proof -> blood test for antibodies -> urea breath test -> biopsy combined with urease test and histological exam TREATMENT: - triple therapy • Antibiotics: amoxicillin and clarithromycin • Proton pump inhibitor: such as omeprazole DISCOVERY: - Barry Marshall observed curved bacteria colonizing the site of infection in the stomach - Having a hard time convincing the medical establishment, that h.pylori is what causing ulcers and can be treated, he drank helicobacter pylori - they observed the same bacteria in the site of inflammation and treated him and recovered LIFECYCLE: 1. INFECTION - H. Pylori infects the lower part of the stomach, aritrium 2. INFLAMMATION - it causes inflammation of the gastric mucosa (gastritis) - this is often aymptomatic 3. ULCER - Gastric inflammation may lead to duodenal or gastric ulcer 4. BLEEDING ULCER - severe complications include bleeding ulcer and perofrated ulcer
GUINEA WORM (larval roundworm) ***
FEATURES: - painful, itchy once the worm comes out of the skin - female worm releases toxin to form a blister in the skin TRANSMISSION: - orally (from contaminated water) LIFECYCLE: ‣ Once the worm gets in the water —> it releases tons of larvae into the water —> tiny water fleas/copepods ingest the larvae —> when a person ingest the water containing fleas —> water fleas are digested —> larvae are released into the stomach —> larvae resist digestion by migrating to small intestine —> they will penetrate the intestinal wall —> where they grow into worms and mate —> fertilized female worms (3 feet) move to connective tissue (usually lower limbs) —> a year later, the worm forms a painful blister near the skin surface —> the blister burst and exposes the worm PREVENTION: - By Carter Foundation - they have filtering cloth to filter copepods in the water TREATMENT: - removal of worm by wrapping the worm around the stikc
True
Facilitated diffusion and active transport require a carrier protein to mediate the movement across the plasma membrane
Carrier proteins in the membrane
Facilitated diffusion is limited by
Norovirus
Family: Caliciviridae - ssRNA, non-enveloped virus epidemiology: ver common, major etiological agent for 'stomach flu,' believed to cause >50% of food borne outbreaks of gastroenteritis clinical features: incubation 12-48 hrs primary symptoms: vomiting, watery non-bloody diarrhea, mausea secondary symptoms: fever, headache, chills, muscle aches, tiredness treatment: supportive only complications: dehydration transmission: recal-oral route - contaminated food or water, person to person viral shedding - still active after symptoms have subsided highly contagious - infectious inoculum < 100 viral particles environmental / famine contamination: aerosolized vomitus
Poliomyelitis (polio or infantile paralysis)
Family: Picornaviridae (Hep A virus, coxackieviruses, echovirus, rhinovirus), three serotypes, PV1, PV2, PV3 virology: ss (+) RNA, simple virus - non-enveloped viruses with only RNA and a non-enveloped icosahedra protein coat clinical features: 95% infections asymptomatic, <1% paralytic poliomyelitis (FDR) - Muscle paralysis, skeletal deformity, and movement disability in paralytic poliomyelitis transmission: fecal-oral route: contaminated food/water, person to person viral shedding: within 24 herself exposure highly contagious = very low infectious inoculum vaccines: inactivated vaccine (IPV): all three PV serotypes grown in vitro, inactivated by formaldehyde, protects against paralysis, but not transmission of PV attenuated vaccine (OPV) (newer): all three PV serotypes attenuated through serial passage, able to replicate in GI tract but not CNS - used for global campaigns bc (1) immunity in GI tract (2) ease of administration - discontinued in US in 2000 to avoid vaccine-associated poliomyelitis
2
Fermentation: Amount of ATP
Glycolysis
Fermentation: Pathways
yeast, bacteria
Fermentation: Which organisms?
no
Fermentation: is O2 required
TCR diversity
Genetically how you get a t cell receptor, similar to how you get a b cell receptor Instead of heavy and light chain have alpha and beta Piecing together one variable segment out of 80ish that there are, one joining segment out of 61, a constant region What you get in end is not anything coded in germline DNA Most of diversity occurs in antigen recognizing portion
International Committee on Taxonomy of Viruses (ICTV) criteria of virus classification (5):
Genome composition: DNA/RNA, single or double stranded, linear or circular Capsid symmetry: capsid or core particle, helical/ icosahedral Envelope: presence of host derived Size of the virion Host range: related viruses infect same/ related hosts
Group V: (-) sense single stranded RNA viruses
Genome of template RNA Need to package RNA dependent RNA polymerase for transcribing (-) RNA to (+) mRNA
RNA virus replication
Genomes contain (+) strand RNA allowing virus to replicate entirely into cytoplasm without any DNA intermediates Virus binds to surface receptor (+) strand RNA uncoated by insertion through cell mem into cytoplasm Genes translated by host ribosomes to make RNA dependent RNA polymerase which makes (-) RNA strand that is a template for other mRNA and progeny
Germicide effectiveness levels
Germicide= something that kills microbes High-level kill all pathogens, including endospores Unfortunately not usually things that you can very easily use in most environments Ex: Formaldehyde, gaseous agents like ethylene oxide (poisonous) Intermediate-level kill fungal spores, protozoan cysts, viruses and pathogenic bacteria (most stuff) Very frequently used Ex: methanol Low-level germicides kill vegetative bacteria, fungi, protozoa, and some viruses Don't kill all viruses Normal soaps- disrupt cell membranes, no impact on cysts or spores Safest for humans and pets
Is Giardia (protozoan pathogens) or viruses harder to kill?
Giardia, they form cysts
functions of influenza virus proteins
HA proteins (hemagglutinin): attaches to receptors and initiates virus entry cell receptor: for mediated endocytosis nucleocapsid: coat protein of nuclei acid and helps with assembly/ packaging NA (neuraminidase): removes sialic acids from glycoprotein
air
HEPA filters are used to remove microbes from
rare
HGT is common or rare?
non nucleoside noncompetitive inhibitions analog inhibition of nucleic acid synthesis antiviral drug
HIV infections
independent plasmid transfer.
Hfr transfer involves all of the following except
Gaseous agents
High level disinfectants Used in closed chambers to sterilize items Denature proteins and DNA by cross-linking functional groups Can be hazardous- explosive, poisonous, carcinogenic Gas instead of heat like autoclave Ethylene oxide
All
High level germicides kill ______ pathogen
chemostat and adding nutrients
How industrial microbiologists prevent the onset of the stationary phase
Six
How many carbon dioxide molecules are produced by the complete aerobic breakdown of one glucose molecule?
True
Hydrolysis reactions are catabolic reactions that use water to split the reactant into smaller subunits.
True
Identification of unique DNA fingerprints relies on the presence of single nucleotide polymorphisms among samples
B cell secretion
If B cell recognizes antigen without any help from T cell, recognizing repetitive isotope- some sort of sugar, will secrete IGM only If it recognizes same antigen with help from helper T cell that recognizes something as well, then can secrete other types of antibodies (ex IgG) that might result in a stronger immune response
nonsense
If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATE (stop)?
Nonsense
If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, which type of mutation would change the sequence to THE CAT ATE (stop)?
Alterations of cell walls and membranes
If you disrupt cell wall, make cell susceptible to osmotic effects and it will often die If you disrupt cytoplasmic membrane, cellular contents will leak out If you disrupt viral envelope (responsible for allowing attachment), it won't be able to cause infection
48
If you start with 3 double-stranded DNA fragments, after 4 cycles of PCR you will have ____ fragments
The major class of immunoglobulin found on the surfaces of the walls of the intestines and airways is secretory
IgA
which Ab serotype is the main one in secretions such as tears and mucus and plays a role in first line defense at the mucosal level
IgA
which ab serotype is found on all B lymphocytes
IgD
the immunoglobulin class that mediates type 1 hypersensitivity is
IgE
which Ab serotype is found in allergy and worm infection in which its Fc region binds to eosinophils, basophils, and mast cells
IgE
True
In a commensal relationship, the commensal benefits but the cohabitant is neither harmed nor benefitted
True
In bacteria, initiator tRNA carries formyl methionine
The 5' end of the mRNA binds to the small ribosomal subunit, and the large subunit joins, creating the P and A sites where reactions between codons on the mRNA and anticodons on tRNA are stabilized.
In order for protein synthesis to begin, which of the following statements reflects the correct sequence of events?
Colony; cell
In the viable plate count method, a measured volume of a culture is evenly spread across an agar surface and incubated. Each _____ represents one _____ from the original sample
aminoglycosides
Infections caused by gram-negative bacilli are often treated with
DNA virus replication: HPV
Infects basal epithelial cells and virions enter cytoplasm by binding and membrane fusion Virion uncoats and releases double stranded genome in which enters nucleus where it is replicated by host DNA polymerase and transcribed by host RNA pol
mechanisms of antimicrobial action
Inhibit cell wall synthesis in bacteria- major way many antibiotics work Inhibit protein synthesis- both antibacterial and antiprotozoal drugs that work this way Disrupting cytoplasmic membrane- variety of drugs that work this way- against fungi, bacteria Inhibiting metabolic pathways- target a variety of different organisms Inhibiting DNA and RNA synthesis- particularly important for antivirals but also some antibacterial, antiprotozoal, antifungal Inhibiting pathogens attachment or recognizing a host- important for virsuses but can also work for other types of organisms
Summarize what occurs in each of the three stages of transcription.
Initiation: RNA pol binds to beginning of gene, melts open DNA helix and catalyzes placement of first RNA nucleotide Elongation: add ribonucleotides to 3' end Termination: sequences at end of gene trigger release of pol and completed RNA
extracellular pathogens and toxins
Interaction between cell mediated and humoral immunity A lot of times those extracellular pathogens and toxins can be recognized by B cells and T cells, when something binds to B cell receptor, it gets engulfed by B cell, and chewed up, and then gets displayed on MHC class II, when it gets displayed on MHC class II, the CD4 T cells bind to that and activate the B cells to be able to undergo isotype switching- to secrete different types of antibodies (Ig) that are more effective in clearing that infection Degraded in endocytic vesicles (low pH)
ATP, catabolism, anabolic
Interaction: _____ made in ______ is used in _____ reactions
Amination
Intermediates from the Krebs cycle can be converted to amino acids by the process of
Tyndallization
Intermittent sterilization, which uses 3 days of lower temperature steam for short periods of time, is also called
Why don't all antimicrobials work equally well on all pathogens?
Intrinsic differences in structure and metabolism (virus very different from fungus), natural resistance (microbe that produces antibiotic will be resistant to it), and acquired resistance (transfer of genes from one microbe to another)
False
Introns have no detectable functions
experimental epidemiology
Involves testing a hypotheses Confirm cause of a disease Kochs postulates Efficacy of a potential treatment Efficacy of a preventative measure How effective are condoms at preventing HIV infection? What is causing microcephaly? Is it zika virus?
Halogens
Iodine, chlorine, fluorine intermediate-level disinfectants Damage enzymes via oxidation or denaturing Work pretty well Bleach Smells bad Stains clothes Some people don't react well to it Watch concentrations
gamma
Irradiated food is safe because ________ radiation passes through the food and makes it safe to eat.
spectrum of activity
Isoniazid- mycobacteria, some gram-neg Polymyxin- some gram neg Penicillin- some gram-neg all gram pos Streptomycin- almost all mycobacteria and gram-neg bacteria Erythromycin- gram neg, gram pos, chlamydias, rickettsias Tetracyclin- gram neg, gram pos, chlamydias, rickettsias Sulfonamids- half gram neg, gram pos, chlamydias, rickettsias Azoles- protozoa and fungi, few helminths Niclosamdie- most helminths Praziquantel- more helminths Arildone, Ribavirin, Acyclovir- some viruses
False
Isopropyl alcohol wiped across a skin site can sterilize it.
mutation frequency
It is calculated simply as the ratio of mutants per total cells in the population
True
It is possible to identify mRNA molecules using fluorescently labeled cDNA
binary fission
It is the most common form of reproduction in prokaryotes such as bacteria.
which bacteria is a gram negative bacilli that has a prominent polysaccharide capsule which acts as a virulence factor?
Klebsiella pneumoniae
recognition of PAMPs by leukocytes
Leukocytes in Innate immunity recognizes pathogen associated molecular patterns Toll-like receptors (TLRs) used by phagocytes Cytoplasmic or phagosome membrane Recognize certain things- ex: one recognizes flagellum protein NOD-Like Receptors (NLRs) used by all leukocytes Inside the cell Trigger inflammation, apoptosis Retinoid acid-inducible gene-1 (RIG-1)-like receptors (RLRs) used by phagocytes Cytoplasm Recognize things like viral nucleic acids, can trigger production of interferons which help to fight off viruses All receptors that make it so innate immune system is not completely non-specific, recognizes invader is there
which is a prominent foodborne pathogen that is a cause of meningitis?
Listeria monocytogenes
True
Lithoautotrophs use inorganic nutrients for carbon and energy sources
The chemical being tested is mutagenic.
Looking at your results of the Ames test using bacteriological agar medium plates lacking the amino acid histidine, you find that there are many colonies growing on the agar. How do you interpret this result?
Inhibition of protein synthesis
Lots of places they can target this Drugs can selectively target translation in bacteria Lots of places you can target translation Why is translation a reasonable target if you are trying to have something that is toxic to bacterial cells but not to your cells?- protein synthesis takes place on ribosomes, have different size ribosomes for prokaryotic and eukaryotic cells, pro= 70s euk=80s, opens up a way to target selectively so that you don't inhibit protein synthesis in your cells Only issue- your mitochondria still have 70s ribosome so can have effects within mitochondria EX: change shape of 30s ribosome, block site for tRNA, inhibit peptide-transferase reaction, inhibit mRNA movement
Duration of exposure
Lysol (low-intermediate) only works properly if allowed to sit for sufficient amount of time
Nonspecific chemical defenses
Lysozyme- can chew up bacteria Defensins (including dermicidins)- antimicrobial peptides Complement- series of proteins that come together to form a cascade that can have a variety of outcomes including lysing a bacterial cell Interferons- inhibit spread of viruses, don't inactive or kill
what are antibodies made against in rheumatic fever
M protein of Streptococcus pyogenes
what are alpha and beta chain heterodimers that are found on the surface of a relatively small number of cells such as dendritic cells, macrophages, and b cells?
MHC Class II
what is a complex of genes coding for a family of proteins which function in the immune system that is also known as human leukocyte antigen?
MHC complex function: bind peptide fragments from the antigen and display them on the cell surface for recognition by the t cells
Tc cells recognize epitopes only when the latter are held by
MHC proteins
MHC diversity
Many alleles in population, multiple loci, codominant expression- all alleles you have you express Surface of your cell covered with a variety of MHC molecules MHC alleles are encoded in the germline DNA no somatic recombination 1 in 10,000 unrelated people will share an MHC type by chance MHC genes account for about 50% of the genetic impact on immunity, influences your susceptibility to autoimmune diseases Have to have close MHC match or will reject organ transplant Fewer mismatches= organ more likely to survive
error proof repair pathways include
Methyl mismatch repair, photoreactivation, nucleotide excision repair, base excision repair, and recombinational repair
False
Microbes can utilize only carbohydrates for energy production
assess the size of a particular microbial population.
Microbes in a biofilm use quorum sensing to
Capnophiles
Microbes that require high CO2 conditions
no reproduction
Microbial death occurs when there is
e. all of the choices are correct.
Microbial resistance resulting from mutation occurs because a. mutations are passed between organisms. b. prokaryotic genomes undergo mutation often. c. prokaryotic genomes undergo mutation rapidly. d. short generation times accumulate mutations in populations. e. all of the choices are correct.
Macronutrients
Microorganisms require large quantities of ______ for use in cell structure and metabolism.
Macronutrients
Microorganisms require large quantities of ________ for use in cell structure and metabolism
Trace elements
Microorganisms require small quantities of _______ for enzyme function and maintenance of protein structure.
Pregnant neighbor has a sore throat and she tells you that she is taking some antibiotics that she has leftover from a previous infection. Why is this a bad idea?
Might not be safe for a pregnant woman to take, bacteria might be resistant to it, might be expired, might not be right drug for infection, doesn't have right amount
produces several different acids plus CO2 and H2 gases.
Mixed acid fermentation
Escherichia
Mixed acid fermentation bacteria
Restriction endonucleases for bacterial defense against viruses
Modify DNA by adding methyl groups to bases of certain sequences Then expression restriction endonucleases cleaves DNA lacking methylated patterns including viral DNA
How is the adaptive immune system different from the innate immune system?
More specific, takes longer to respond First time it sees a new antigen there are some extra steps that have to happen for it to become activated It has memory- upon second and subsequent encounters with an antigen, it can respond much more quickly than it did the first time
Damage to proteins and nucleic acids
Most common way chemical methods work and how heat works Extreme heat or certain chemicals denature proteins Chemical, radiation, and heat can alter or destroy nucleic acids Damage proteins, metabolism of cell is not going to work, may alter structure of cell Damage nucleic acids, cause mutation, too much mutation kills cell Chlorine bleach denatures proteins Radiation good for destroying and altering nucleic acids Biosafety light under biosafety hood so you don't have to use chemicals
Coenzymes
Most electron carriers are
False
Most microbial contaminants of food are killed or inactivated at freezing temperatures.
Organic Compounds
Most of the dry weight of a microbial cell is from ______.
Organic compounds.
Most of the dry weight of a microbial cell is from _______.
How do organisms become resistant to drugs?
Mutation of a chromosomal gene, acquisition of a plasmid carrying a resistance gene, lots of different mechanisms
Hydrogen is transported from other reactions to the electron transport chain by ______.
NADH and FADH2
do bacteria have a nucleus
NO they have their DNA in nucleoids
Norovirus Calicivirus, +ssRNA virus, ___________, Icosahedral _______ Infectious-10 particles can cause infection-millions shed in vomit, billions in feces Resistant to _________, Can remain infectious for up to 2 weeks on surfaces, Resists many common ____________ and hand sanitizers, Need to be heated on to ________ (on contaminated food), Can withstand pH 3-10 16% of all ___________ 58% of acquired _________ illnesses Incubation _________ hours (range 12-72 hours) Shed from time of symptoms up to _________ after you feel better. after
Naked Very drying disinfectants 140 F gastroenteritis food borne 24-48 2 weeks
Group III: double stranded RNA viruses
Need viral RNA dependent RNA polymerase to make mRNA by transcribing directly RNA genome
What does Actinomycin D do?
Non Selectively binds to DNA and inhibits transcription elongation
A _______ mutation occurs when an early stop codon is introduced; a _______ mutation occurs when any other amino acid is substituted
Nonsense; Missense
inflammation
Nonspecific response to tissue damage Characterized by redness, heat, swelling, and pain Two types Acute- good, prevent infection, occurs when you have an injury that needs to be prepared Chronic-bad, repetitive injury or immune system stimulated repeatedly in inappropriate manner, causes tissue damage
skin
Not easy to penetrate- most microbes can't get in through your skin (some worms can burrow) Good at keeping things out- 2 layers Epidermis- outer layer- tightly packed cells that few pathogens can penetrate, shed dead cells so whatever bacteria is present just fall off Dermis- inner layer- contains collagen- give skin strength and pliability Also have dendritic phagocytic cells- Langerhans
BCR and antibody diversity
Not reliant on just having every single B cell and t cell receptor encoded in DNA within each individual cell, we have somatic recombination occurring B cell receptor different in each cell due to unique somatic recombination and junctional diversity Each B cell receptor has 2 light chain and 2 heavy chains, pick form two different light chain loci to use, within whatever locus you pick, pick one variable region (30 to pick from) and one joining region ( a few to pick from) and put that onto constant region- depends on if it is B cell receptor or antibody Heavy chain- pick one of 60 heavy chain variable regions, then pick one diversity region out of 27, then pick one joining region out of 6 options Cutting out intervening DNA and piecing these together Recombination of DNA in immune cells, permanent Paste together with random nucleotides in middle- creates junctional diversity Somatic hypermutaion/affinity maturation- occurs with long term or repeated exposure Already had recombination and intial immune response, upon subsequent responses there will be rapid mutation throughout the genes for heavy and light chains, then there will be selection for antibodies that bind the best, random mutation process Those b cells will go to proliferate and create more antibodies How you get a really strong humoral immune response Constant region determines if it is IGG, IGA, IGM, or is it fixed to membrane- is it b cell receptor?
Prebiotics
Nutrients that encourage the growth of beneficial microbes in the intestines are known as
assigning ORF to putative functions
ORFs with sufficient homology to known proteins
False
Obligate saprobes can adapt to a living host
Both tetracycline and chloramphenicol are correct.
Of the following list, which antibiotics affect protein synthesis?
Electrons and hydrogen
Often the mnemonic device "OIL RIG" is used to remember the principles of redox reactions. Oxidation Is Loss and Reduction Is Gain of what?
DNA ligase
Okazaki fragments are attached to the growing end of the lagging strand by
What would be the direct result of a bacterium losing the ability to produce DNA ligase?
Okazaki fragments could no longer be joined together.
Minimum inhibitory Concentration (MIC) test
One way: solid media- concentration of drug imbedded in paper membrane, goes from high to low, see minimum inhibitory concentration, see how susceptible or resistant bacteria is, doesn't tell dosage clinically- just correlate to know if you need to use more or less of drug Other way: liquid form, different amounts of drug in each test tube, when you have growth it is too dilute
False
Only yeast produce alcohol as a fermentation product.
Vancomycin
Organisms have a tendency to develop resistance to beta-lactams, and humans can develop allergic reactions to them. A drug that also targets the cell wall and can be used as an alternative is
faculative halophiles
Organisms that do not require high salt concentrations but can tolerate salt concentrations at 2 percent
Saprobes
Organisms that feed on dead organisms for nutrients are called
Hyperthermophiles
Organisms that grow in extremely high temperatures (80-100 degrees C)
where is the replication origin?
OriC
True
Oxygen-containing ions are used by some bacteria in their electron transport system
True
Oxygen-containing ions are used by some bacteria in their electron transport system.
True
Ozone is a very effective disinfectant
The results of your test tubes suggest which of the following?
PTU is an inhibitor of catechol oxidase
Type II DNA restriction endonucleases
Palindromic site and cleaves at those sites most common for cloning
What does alpha hemolysis look like?
Partial digestion of the RBC & Hb; brownish-greenish color
reduces the number of vegetative forms
Pasteurization
chemical components of skin
Perspiration secreted by sweat glands Cools body Salt- inhibits growth of pathogens (excpetion = staph) Antimicrobial peptides- dermicidins Lysozyme- destroys cell wall of bacteria Sebum secreted by sebaceous (oil) glands Helps keep skin pliable- if gets dry, cracks, and susceptible to infection Lowers pH of the skin- acidic environments not favorable for bacterial growth
evidence for phage effects that are positive
Phages may limit the bacterial numbers to levels that the human immune system can tolerate. - Phage particles may modulate immune system activity by suppressing T-cell activation and tumor formation. - Phages may attack biofilms.
phagocytosis
Phagocytes move towards microbes that are present (chemotaxis), attach to microbe (adhesion), pseudopodia form around the microbe and take them into the cell(ingestion) Phagosome and lysosome fuse (phagolysosome) then bacteria are chewed up and killed by enzymes present in lysosome (maturation and microbial killing), eliminate remnants of microbes via exocytosis (elimination) Some bacteria can prevent fusion Some can avoid getting chewed up after fusion Capsule makes them hard for phagocyte to recognize
macrophages
Phagocytic cells- phagocytosis Wandering macrophages- travel throughout the body, move around in blood go through process called diapedesis to go into tissue and then come back Fixed macrophages- move through the body and then when they go into tissue they stay there, don't ever come back Ex: microglia, cooper cells
Phenol and Phenolics
Phenol and Phenolics Phenol= Original disinfectants, smells bad, kind of toxic Pheonlics safer and smell better Intermediate to low level disinfectants Denature proteins Disrupt cell membranes Effective in presence of organic matter Remain active for prolonged time Strong odor Side effects- some people react to it, asthma, skin problems, some not pet safe Lysol Watch contact time Reduce microbes on surfaces
chemical methods for microbial growth
Phenols- lysol Alcohols- ethanol Halogens- bleach Oxidizing agents Surfactants Heavy metals Aldehydes Gaseous agents Enzymes- chew up certain microbes depending on what their target is Antibiotics- use as antibodies
Which of the following represents the correct sequence of events during photosynthesis?
Photosystem II (ATP production)----> Photosystem I (NADPH production)
Which viruses enter cells via mechanical transmission, a nonspecific access through physical damage?
Plant viruses Plant viruses infect cells without binding to specific membrane receptors. Most animal viruses and bacterial viruses (phage) enter cells by binding to cell surface proteins.
mechanism of how plant viruses enter a host cell and transmit to uninfected cells
Plant viruses typically gain entry through a wound or other structural damage done to the plant, such as by an insect vector. Once inside, however, plant cells are connected internally by structures called plasmodesma, allowing travel between cells
Most resistant --> most susceptible
Prions bacterial endospores cysts of cryptosporidium (protozoan) mycobacteria cysts of other protozoa small nonenveloped viruses active-stage protozoa (trophozoites) fungal spores most gram-negative bacteria vegetative fungi large nonenveloped viruses most gram-positive bacteria enveloped viruses
True
Prions require more extensive methods of sterilization than are needed for bacterial endospores
Drag the statement to the correct column based on whether it describes transcription/translation in prokaryotes vs. eukaryotes. Two labels are not used
Prokaryotes: -mRNA is not processed -mRNA lacking introns -mRNA often polycistronic -transcription and translation occur in cytoplasm -70S ribosomes Eukaryotes: -5' cap and 3' poly A tail added -mRNA with introns and exons -mRNA is always monocistronic -transcription occurs in nucleus, translation in cytoplasm -80S ribosomes
Categorize the descriptions of mRNA as being true for either prokaryotes or eukaryotes
Prokaryotes: -polycistronic messages -ribosome-binding site Eukaryotes: -introns -polyadenylated -5' cap
interferons
Protein molecules released by host cells or nonspecifically inhibit the spread of viral infections Cant help infected cell but help surrounding cells from being infected Production stimulated by binding of viral DNA/RNA to TLRs on immune cells, as a result those cells will begin to excrete interferons, interferons will then stop the spread of the virus, tell cells to chew up viral DNA Cause many symptoms associated with viral infections Ex flu symptoms IFN-alpha and IFN-beta Activate natural killer cells- fight off viruses Induce production of antiviral proteins in neighboring cells Degrade mRNA (degrade cell mRNA also but not a big deal) Inhibit protein synthesis A lot of different types of cells can produce interferons
proteome analysis
Proteins encoded by genomes Useful for distantly related viruses because protein sequences often show relatedness and obscured by nucleic acid sequences by silent mutations
True
Proteomics is the study of all proteins that are expressed by an organism, whereas genomics refers to the study of the organism's entire genome, not simply the protein-coding regions.
All of the choices are correct
RNA molecules differ from DNA molecules because only RNA has ribose has uracil is typically one strand of nucleotides does not have thymine All of the choices are correct.
promoter sequence.
RNA polymerase binds to the
genetic resistance for bacterial defense against viruses
Random mutations in genomes as reproduce When attacked by bacteriophages, undergo natural selection and mutants that prevent infection survive better
Pseudomonas fluorescens
Recombinant strains of _____ are released to colonize plant roots to produce an insecticide to destroy invading insects
Denitrification
Reduction of nitrogen-oxygen ions and compounds by some bacteria is called
Tregs
Regulatory T cells Suppress/downregulate immune response Very important in preventing autoimmune disease Lacking certain of these associated with autoimmune disorders Ensure at some point you stop having an immune response Make sure you don't respond to own cells that you shouldn't respond to Normal regulation of immune responses
Group VII: pararetroviruses/ DNA reverse transcribing viruses
Replication cycle that needs reverse transcriptase Copy double stranded DNA - RNA - reverse transcribes RNA to progeny DNA
TRUE
Repressible operons are normally turned on in the cell
THE PRODUCT
Repressible operons require that ______________ binds to the repressor protein before it can bind to the operator.
microerophiles
Require O2 levels of 2-10%, damaged by atmospheric % of O2 because of limited ability to detoxify hydrogen peroxide and superoxide radicals
palindromes
Restriction endonucleases recognize and clip DNA base sequences called
The following HIV encoded enzymes work in which temporal sequence during an HIV infection?
Reverse transcriptase, integrase, protease
how does transcriptional attenuation affect low trp [ ]
Ribosome following behind RNA pol stalls over trp codons and doesn't over region 2 so 2:3 stem loop forms = make more genes = more trp
how does transcriptional attenuation affect high trp [ ]
Ribosome translates stop codon between 1:2 and stops preventing 2:3 stem loop from forming RNA pol transcribes through region 4, 3:4 stem snaps together and stops transcription
Antibiotic mechanisms of action targeting transcription
Rifampicin B and actinomycin D
which serogroup of Neisseria meningitis caused severe outbreaks of meningococcal urethritis cases in heterosexual males?
ST-11 serogroup C is a capsule defective strain because of genetic recombination
Which HIV envelope protein is necessary for host cell entry?
SU
what culture is fungi grown in?
Sabourand's Dextrose Agar (SDA)
POLIOVIRUS (Picornaviridae)
Same family as hepatitis A virus, coxsackieviruses, echoviruses, and rhinoviruses\ THREE SEROTYPES ‣ PV1 ‣ PV2 ‣ PV3 CLINICAL FEATURES: *** ‣ Symptoms: • Asymptomatic (95% infections) • Symptomatic (5% of infections) ‣ Fever ‣ Headache ‣ Sore throat ‣ <1% paralytic poliomyelitis (virus replicating in motor neurons; get out of GI tract and infect neurons) ◦ Muscle paralysis ◦ Skeletal deformity ◦ Movement disability ‣ Diseases *** • Paralytic poliomyelitis — virus get out of GI tract and infects the neuron by replicating there • Post-polio syndrome ◦ 25% of paralytic poliomyelitis survivors develop post-polio syndrome decades later ◦ including muscle weakness, extreme fatigue, or paralysis again MOST. FAMOUS PATEINT*** ‣ Franklin Delano Roosevelt (1882-1945) • Contracted polio from swimming at the age of 39 VACCINES 1. IPV "Inactivated vaccine" • 1955 Jonas Salk • All three PV serotypes were grown in vitro in african green monkey kidney cells and inactivated by formaldehyde • Advantage/disadvantage: ◦ Protects against paralysis, but not transmission of PV (it does not stop the polio from replicating in the GI tract) ◦ Administered thru injection ◦ Much safer but less effective 2. OPV "Live, attenuated vaccine" • 1963 Albert Sabine • All three PV serotypes were attenuated thru serial passage thru various animals and cells • Advantage/disadvantage: ◦ Able to replicate in GI tract but not CNS ◦ it stops the transmission as well • Used for global campaigns because: ◦ its immunity in GI tract ◦ Easily administered (orally) • Very effective but in some few cases, can cause REVERSION ◦ Discontinued in US in 2000 to avoid vaccine-associated poliomyelitis ◦ IPV is used exclusively
natural killer lymphocytes (NK cells)
Secretes toxins onto the surface of virally infected cells and tumors Kills your own cells Cells infected with virus often stop expressing certain things that would let a t-cell recognize it, natural killer cell recognizes things on surface of target cell, realize that other things are missing, indicate infection, release toxic granules
Minimum bactericidal concentration (MBC) test
See if an antibacterial both inhibits and kills bacteria (instead of just inhibiting growth) Do an MIC in liquid tubes Take a sample out of each tube and plate on to nutrient agar, see where you get growth, look for lowest concentration where you get no growth at all, some drugs you would never get to that- bacteriostatic, bacteriocidal- can find concentration that killed all bacteria
How do we get drug resistance?
Selective pressure- have a bunch of cells, some are sensitive to drug, randomly some are resistant, when you expose it to the drug, especially at lower concentrations, the resistant ones will survive, resistance on a continuum (somewhat resistant/susceptible), now no other bacteria to compete with, resistant ones grow to a large amount, if you treat with drug now won't kill any, select for resistant bacteria when take only small amount of antibiotic
the drug is effective against the target organism, but not the human host.
Selective toxicity exhibited by a drug means that
the target organisms but not vertebrate cells.
Selective toxicity refers damage to
False
Selective toxicity should be avoided when developing a new antimicrobial drug
first line of defense
Skin and mucous membranes When you get a cut or anything that compromises those, you are more likely to get an infection Structurally act as barrier but also have chemicals and processes that allow them to act as barrier and prevent infection
denature
Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state, the three-dimensional configuration of the proteins
Evaluation of antimicrobial drugs
Spectrum of activity- what types of organisms does it work against? Efficacy- Dosage required to be effective (how much, how long, how often) Routes of administration (effective dose differs from pill to IV) Overall safety Side effects
Kelsey-Sykes capacity test
Standard test in industry Add bacteria to chemical being tested Take broth culture of bacteria, add an alocod of that into chemical you want to test Remove samples at predetermined time intervals Inoculate growth media and see how long it takes for it to completely inactive the organism (if it does) Limitations- idea of how it works, never really dunk anything in chemical in real environment
intravesicular pathogens
Stays in phagolysosome- macrophage engulfed it, tried to chew it up, it didn't work When little bits are chewed up they are shown on MHC class II, and presented to CD4 T cells, once CD4 is activate, it can activate macrophage so that it is able to release stronger toxins and kill intravesicular bacteria and parasites Degraded in endocytic vesicles (low pH)
ionizing radiation
Sterilization of medical and laboratory equipment and preservation of food, gamma rays and x rays
Filtration
Sterilize heat-sensitive materials like antibiotics or vaccines, passes through a filter
by interfering with both the initiation and elongation stages of translation.
Streptomycin, an aminoglycoside, inhibits protein synthesis
Antibiotics
Substances that are naturally produced by certain microorganisms that can inhibit or destroy bacteria are called
2 pyruvate -> 2 acetyl CoA + 2 CO2 + NADH
Synthesis of Acetyl-CoA reaction
binding to operator
Synthesis of a repressible enzyme is inhibited by
ubstrate bound to repressor
Synthesis of an inducible enzyme requires
lymphocyte that predominates in blood
T cells (NOT B cells, plasma cells, or memory cells)
SCID is deficient in...
T cells and B cells Severe combined immunodeficiency
why aren't B cells activated against our own cells?
T cells and B cells that would bind to your cells get eliminated in their process of development Initially process of creating B cells and T cell receptors genetically is totally random- some will bind to your cells With B cells, develop in bone marrow, when they bind to cells expressing autoantigens, they will die via apoptosis if they bind strongly, if they bind weakly they are allowed to continue Bc they are often dependent on helper T cells, if you have a strong process of eliminating self reacting helper t cells than that protects you from your B cells bc they wont become fully activated
why aren't T cells activated against our own cells?
T cells and B cells that would bind to your cells get eliminated in their process of development Initially process of creating B cells and T cell receptors genetically is totally random- some will bind to your cells With T cells, develop in thymus, in thymus you express antigens from all over your body, they are displayed on MHC class 1 and 2, the T cells need to recognize MHC class 1 or 2 you're your antigen a little bit, if they don't recognize it all, die by apoptosis, if they bind really well then mostly die of apoptosis or become regulatory T cells and downregulate immune response to that antigen, if bind weakly then go on to become normal T cells
COMMON FEATURES OF FECAL-ORAL PATHOGENS
TRANSMISSION - entry is mouth - exit is fecal - direct contact (human to human) - ex: caretakers at daycare, nursing homes, family members, food handlers at restaurants, contaminated water, swimming pool, contaminated food - indirect contact HOST: - only humans (prinicipal host) - NO animal reservoir SYMPTOMS: - Diarrhea, nausea, vomiting, and fever (when pathogens are confined in the GI tract) - More severe symptoms when disseminated ◦ This occurs when the infection is confined in GI tract, it can spread to the blood and to other organs INFECTIOUS DOSE: - low infectious inoculum (10-100)
10) When building a cladogram, the length of the horizontal branch is based on the calculated percent similarity between organisms.
TRUE
2) Chloroplasts possess circular DNA and reproduce by binary fission.
TRUE
3) As molecular techniques improve, scientists are finding it necessary to reclassify some genera.
TRUE
5) Pure cultures of the same species are not always identical in all ways.
TRUE
8) Serological testing is used for screening bacterial isolates for similarities.
TRUE
9) Western blotting is an immunological test used to identify the antibodies in the serum of an individual suspected of having Lyme disease.
TRUE
Mutualistic
Termites are insects that require the protozoan Trichonympha in their gut to synthesize the enzyme cellulase to degrade the cellulose in wood. The protozoan uses the end products of the cellulose breakdown (glucose). This is a(n) relationship. ____________
Tetracyclines
The _____ are drugs that deposit in developing teeth and cause a permanent brown discoloration.
True
The advantage of germline therapy over somatic cell therapy is that the normal gene is inserted into an egg, sperm, or developing embryo so that the repair is present in every cell of the organism as it matures to adulthood.
Antisepsis
The alcohol wipe used on a patient's skin before an injection is an example of
amphotericin B
The antifungal drug that can be used to treat serious systemic fungal infections is
one helix that runs from the 5' to 3' and the other strand runs from the 3' to 5' direction.
The antiparallel arrangement within DNA molecules refers to
Specialized transduction
The development of virulent, toxin-producing bacterial strains due to the presence of a temperate phage can occur through the process of
Ligase
The enzyme required to attach the sticky ends of DNA and used when splicing DNA fragments into other DNA is
ligase
The enzyme required to attach the sticky ends of DNA and used when splicing DNA fragments into other DNA is
DNA POLYMERASE
The enzyme that can proofread replicating DNA, detect incorrect bases, excise them, and correctly replace them is
phenotype
The expression of genetic traits is referred to as the organism's
True
The field of pharmacogenomics uses knowledge of an individual's single nucleotide polymorphisms to determine how they will respond to a particular drug
the Krebs cycle.
The formation of citric acid from oxaloacetic acid and an acetyl group begins
Gene annotation
The identification of protein coding genes within DNA sequences in a database
Photosystems
The light-harvesting units in the thylakoid membranes are the
the DNA strands run antiparallel to each other and the DNA polymerase can only add nucleotides to the 3' end of the growing strand.
The mechanism of DNA synthesis differs between the two new daughter strands during replication. This is due to the fact that
outside the cell
The most likely place where an exoenzyme participates in a chemical reaction is
target microbial sites that are not present in humans, e.g., the bacterial cell wall.
The most selectively toxic drugs are those that
Frameshift mutation
The most serious type of mutation is a
Diffusion
The movement of molecules from the area of high concentration to an area of lower concentration is called ___________.
facilitated diffusion
The movement of substances from higher to lower concentration across a semipermeable membrane via a specific protein carrier but without energy expenditure is called
removing the drug from the cell when it enters
The multidrug resistant pumps in many bacterial cell membranes function by
Fermentation
The partial oxidation of sugar (or other metabolites) to release energy using an endogenous (within the cell) organic molecule from within the cell as the final electron acceptor instead of ETC.
Gluconeogenesis
The process of forming glucose from various metabolic intermediates is called
Antibiosis
The production of antibiotics is a form of antagonism called
Amphibolism
The property of organisms to integrate catabolic and anabolic pathways to improve cell efficiency is called
NAD+
The reactions of fermentation function to produce _______ molecules for further use in glycolysis.
Cytochromes
The redox carriers of the electron transport system that have a tightly bound metal atom responsible for accepting and donating electrons are
THE LIGHT INDEPENDENT REACTIONS ARE DRIVEN BY ATP AND NADPH ARE GENERATED FROM THE LIGHT REACTIONS.
The relationship between light-dependent and light independent reactions in photosynthesis is that
the light-independent reactions are driven by the ATP and NADPH generated from the light reactions.
The relationship between the light-dependent and light-independent reactions in photosynthesis is that
an example of substrate-level phosphorylation.
The step involving ATP, hexokinase, and the phosphorylation of glucose to glucose-6-phosphate is
ethylene oxide
The sterilizing gas used in chemiclaves is
Metagenomics
The study of genomes of a particular community is called
an organism that expresses proteins coded for by genes that originated in a different organism.
The term 'recombinant organism' refers to
Existing in a very narrow niche
The term obligate refers to
Metabolism
The term used to describe all of the chemical reactions within a cell is
generation time
The time interval from parent cell to two new daughter cells is called
superoxide dismutase and catalase
The toxic superoxide ion is converted to harmless oxygen by two enzymes,
superoxide dismutase and catalase
The toxic superoxide ion is converted to harmless oxygen by two enzymes.
prophylaxis
The use of a drug to prevent imminent infection is called
can remove viruses
The use of filtration for sterilization
Genetic Engineering
The various techniques by which scientists manipulate DNA in the lab are termed
genetic engineering
The various techniques by which scientists manipulate DNA in the lab are termed
sources of heat-stable DNA polymerases
Thermococcus litoralis and Thermus aquaticus are thermophilic bacteria that are
features of viroids
They have no protein capsid. They are replicated by host RNA polymerase. Some have catalytic ability.
photoheterotroph
This microbe is photosynthetic, but in the absence of light it can use organic compounds as an energy source. Its carbon source is an organic compound. The appropriate classification for this organism would be
Photoheterotroph
This microbe is photosynthetic, but in the absence of light it can use organic compounds as an energy source. Its carbon source is an organic compound. The appropriate classification for this organism would be?
The bacterium has changed physically or chemically in some way to be able to destroy the drug or avoid its action, allowing it to grow unimpeded by the drug.
Three classmates from microbiology class are talking about drug resistance. They each disagree about the definition of the term so they state his or her definition and give a justification. Compare the various definitions and justifications below and pick the one that is most accurate.
Osmotic pressure
Traditional way of preserving meats- use salt High concentrations of salt or sugar can inhibit microbial growth Causes cells to shrivel up Less effective at inhibiting fungal growth Fungal growth on country ham normal gives flavor
transcription vs translation
Transcription copies genetic info into complementary RNA translation is from RNA to protein
Which of the following steps in HIV replication is not done by viral proteins? Copying of the RNA viral genome into DNA Integration of viral DNA into host DNA Transcription of viral DNA into mRNA Cleavage of core proteins and enzymes from the polyproteins produced during translation
Transcription of viral DNA into mRNA
True
Transformation and transduction are methods used to introduce DNA into host cells
How can H.pylori be treated?
Triple therapy - antibotics: amoxicillin and clarithromycin - proton pump inhibitor: omeprazole
Inhibiting cell wall synthesis
Typically of bacteria Effective only on growing cells, doesn't kill cells just prevents them from growing Most common agents prevent cross-linkage of NAM subunits Peptidoglycan wall has sugars- NAM and NAG NAM crosslink with eachother to form thick layer of peptidoglycan Beta-lactams Bind to enzymes that cross-link NAM subunits Simple beta-lactams (penicillin) Effective only against aerobic gram-negatives Because gram negative cells have a thinner cell wall they are more impacted by these drugs Variety of synthetic and semi synthetic drugs that have been derived from penicillin- include methicillin, cepalothin, aztreonam- often times will work in places that penicillin wont- more effective When penicillin prevents crosslinking, cell wall is not properly structured, stuff will ooze out of the cell Semi-synthetic derivatives of beta-lactam- tend to be more stable particularly in acidic environments- important for taking as a pill, also more easily absorbed, less susceptible to deactivation so stay active in system for longer, work better against wider variety of bacteria Other non beta lactam drugs that are natural and semisynthetic and work through different mechanisms Ex: bacitracin- inhibits dephosphorylation of certain lipids and those lipids are required for transport of the building blocks needed to make cell wall, vancomycin Target same thing but work in different mechanisms
disinfecting air, transport fluids and surfaces of objects.
UV light is limited as an all-around sterilant because UV light doesn't penetrate well. However, it is only suitable for _______, _______, and ________
dry heat
Used for materials that cannot be sterilized with or are damaged by moist heat Have to use for longer time than moist Ex glass pipettes can be damaged by autoclave Incineration- ultimate means of sterilization
Moist heat
Used to disinfect, sanitize, and sterilize Dishwasher- sanitization Boiling- most common, kills off vegetative cells of bacteria and fungi, protozoan trophozoites, and most viruses within 10 minutes at sea level Endospores, protozoan cysts, some viruses can survive- cysts biggest problem
Analytical Epidemiology
Uses data to determine Cause Mode of transmission Methods of prevention (use models) Useful if kochs postulates cant be applied Often retrospective Better prepared next time Ex: Dr. John Snow
2D gel electrophoresis in obtaining proteomic data
Uses polysaccharide gel electrophoresis to sep proteins from cell extracts in 1D by charge and in 2D by molecular weight
ionizing radiation
Usually used with food Wavelengths shorter than 1 nm Disrupt hydrogen bonding Oxidize double covalent bonds Denature DNA Used to sterilize medical supplies, some food products- meats, vegetable Cut down on number of bacteria present so they wont spoil as quickly Depending on type- can just impact surface or go deep Not radioactive after ex: strawberries
FECAL-ORAL PATHOGENS
VIRAL GI PATHOGENS 1. Hepatitis A (Picornaviridae) 2. Rotavirus (Rotaviridae) 3. Norovirus (Caliciviridae) VIRAL NERVE PATHOGENS 1. Poliovirus (Picornaviridae) BACTERIAL GI PATHOGENS 1. Shigella 2. Helicobacter pylori PARASITIC GI PATHOGENS 1. Giardia intestinalis —> causes Giardiasis 2. Entamoeba histolytica —> causes amebiasis 3. Balantidium coli —> causes balantidiasis 4. Cryptosporidium —> causes cryptosporidiosis 5. Cyclospora cayetanensis —> causes cyclosporiasis HELMINTHS GI PATHOGENS
Functions of antibodies
Viral inhibition- antibodies attach to molecules on surface of viruses, preventing attachment to host cells Agglutination- agglutinins combine with antigens on the cell surface and bind the cells together, restricting movement Precipitation-antibodies cause soluble antigens to precipitate Neutralization-antibodies against toxins are called antitoxins; they react with toxin molecules and neutralize them (antisera = antibodies that bind to toxin Opsonization- opsonins are antibodies that enhance phagocytosis Complement activation- antibodies bridge complement to bacteria, resulting in lysis
innate processes
Vomiting Diarrhea Urination- drink a lot of water when you have a UTI to flush out microbes
Descriptive Epidemiology
Wanting to understand what has happened in an outbreak Tabulation of data concerning a disease Location and time of cases Patient information Try to identify the index case- initial start of epidemic, track back and see where it started, see what caused this
who was the first to demonstrate the correct structure of DNA?
Watson and Crick in 1953
non ionizing radiation
Wavelengths greater than 1 nm UV light causes pyrimidine dimers in DNA Suitable for disinfecting air, transparent fluids, and surfaces of objects People who have ponds Disinfect surfaces of objects that cant be autoclaved
Ways to get rid of bacteria in environment
Ways to get rid of bacteria in environment- chemical methods of disinfection, heat (boil water, autoclave in lab), radiation (UV light), mechanical (physical way of removing microbes)
Multiple Resistance and Cross Resistance
We have a lot more bacteria now that are resistant to many drugs, Pathogen can acquire resistance to more than one drug R-plasmids exchanged, more than one R plasmid, R plasmids can get more than one resistance gene on them Develop in hospitals and nursing homes (biggest source)- people are immune compromised Constant use of drugs eliminates sensitive cells- selective pressure for bacteria that are resistant to multiple drugs- super bugs Ex: 1946- most strains of staph aureus resistant to penicillin, methicillin, gentamicin Now we have MRSA and vancomycin Ex: HIV- becomes resistant to antiviral drugs, not just bacteria Ex: tuberculosis
Bacitracin
What antibiotics is mixed with neomycin and polymyxin to make an antibiotic ointment (neosporin) for superficial skin infections?
singlet oxygen, superoxide radicals, peroxide anion, hydroxyl radical
What are four toxic oxygen products that aerobic organisms potentially need to deal with in order to survive?
active site, reusable
What are the general characteristics of enzymes?
Cell growth and reproduction
What are the macromolecules made during anabolism used for?
CO2 and water
What are the waste products that you "release" from the metabolic process of aerobic respiration?
They can be used over and over, they may or may not require cofactors, their active site is specific to the substrate and their action may involve minerals
What is true of enzymes?
Penicillinase
What molecule will allow some bacteria to be resistant to many penicillins?
molecules.Oxidative phosphorylation
What process is described here? A concentration gradient of H+ ions is created in the periplasmic space by actively transporting the ions across the membrane using the energy liberated when carrier molecules are oxidized. When the H+ ions pass through ATPase, enough energy is generated to add phosphate groups onto ADP
Mesophiles (20-40 degrees)
What temp group do humans belong
temp, pH
What two environmental conditions can affect the rate of enzyme reactions?
Physical
What type of DNA map gives locations and sizes of DNA sections?
Proteins
What type of macromolecule are MOST enzymes?
Nucleotide in RNA
What type of molecule is ATP?
silent
What type of mutation alters the base but not the amino acid being coded for?
True
When DNA is heated the two strands will separate
True
When DNA is heated, the two strands will separate
chemotaxis and flagellar rotation
When an attractant exists, runs and tumbles still occur; however, the length of runs is longer, while the length of the tumbles is reduced, allowing overall movement toward the higher concentration of the attractant.
CRISPR for bacterial defense against viruses
When destroy phage, copy it as CRISPR segment and inserted into spaces at head of CRISPR sequences and now cell is adapted to remember infection
Noncompetitive inhibition
When enzyme action stops due to a buildup of end product that acts as a regulatory molecule, this control is called
noncompetitive inhibition
When enzyme action stops due to a buildup of end product that acts as a regulatory molecule, this control is called
how does gene reduction occur
When evolutionary pressure to retain functional form of gene no longer exists then don't want to repair mutations
Flow Cytometer
When is it important to count the number of cells, determine cell size, and differentiate between dead and live cells, a(n)_______ is used
gene therapy
When patient tissues are transfected with viruses carrying a needed, normal human gene, the technique is called
Linear
When the product of reaction A becomes the reactant of reaction B, this exemplifies a _______ metabolic pathway.
Mitochondria
Where does the krebs cycle take place in eukaryotes
cytoplasm
Where does the krebs cycle take place in prokaryotes?
Mitochondria
Where does the synthesis of Acetyl CoA occur in eukaryotes?
False
Whether an organism is a autotroph or heterotroph depends on its source of nitrogen?
Pasteurization
Which antimicrobial method does not sterilize?
Which components of the immune system protect you from a septic (blood) MRSA infection?
Which components of the immune system protect you from a septic (blood) MRSA infection? Gram positive bacteria Leukocytes- white blood cells Neutrophils- most abundant, in area around site of infection Skin- initially protects you Inflammation- prevent infection Fever- during septic infection CD4 helper T cells- help B cells to produce appropriate antibodies B cells and antibodies- producing neutralizing antibodies that bind to antigen, trigger opsonization- easier to phagocytose- macrophages Dendritic cells- take in bacteria and present to T cells, activate T cell response Memory B and T cells if previous exposure Complement- bore a hole in bacterium, act as opsinate, trigger inflammation
Cells in a culture die at a constant rate
Which is correct regarding the rate of microbial death?
They have genes turned off by a buildup of end product.
Which is incorrect about inducible operons
They are only found in DNA, not in RNA
Which is incorrect about purines?
Messenger RNA
Which molecule is translated into an amino acid sequence?
Phosphoric Acid
Which of the following acids is not used to destroy or inhibit microbial cells in food?
Fuzeon
Which of the following blocks HIV binding to host cell receptors?
PRODUCES GLUCOSE AS AN END PRODUCT
Which of the following characterize the Calvin cycle?
It has expressed traits governed by the genes.
Which of the following is NOT true of an organism's genotype?
Primers, Taq DNA polymerase, nucleotides
Which of the following is a list of the materials required for PCR?
Antisense therapy
Which of the following is a promising treatment for stopping the expression of an unwanted gene?
They include AUG
Which of the following is incorrect about termination codons?
The initiator tRNA in bacteria carries tryptophan.
Which of the following is incorrect about transfer RNA?
E All of the choices are factors
Which of the following is not a factor that affects germicidal activity? A. Material being treated, B Length of exposure, C Strength of the germicide, D Microorganism being treated, E all of the choices are factors
Copper
Which of the following is not a major element of a microbial cell?
Leukophyll
Which of the following is not a photosynthetic pigment?
Reductive Phosphorylation
Which of the following is not a process that regenerates ATP?
Mitotic spindle segregates daughter chromosomes.
Which of the following is not a step in binary fission of bacterial cells?
Increases white blood count
Which of the following is not a therapeutic benefit of interferon? Reduces healing time Increases white blood count Prevents or reduces some cold symptoms Slows progress of some cancers Treats Hepatitis C
Mitosis
Which of the following is not a type of bacterial DNA recombination?
tRNA
Which of the following is not a type of microRNA?
Tetracycline
Which of the following is not an aminoglycoside?
Its small subunit provides the enzymes for making peptide bonds.
Which of the following is not associated with a bacterial ribosome?
Pyruvic acid accepts electrons from NADH
Which of the following is not part of the step that occurs between glycolysis and the Krebs cycle?
It uses the same final electron acceptor as aerobic respiration.
Which of the following is not true of anaerobic respiration?
Involves the action of a bacteriophage
Which of the following is not true of conjugation?
It uses electrophoresis to separate the DNA.
Which of the following is not true of fluorescent in situ hybridization (FISH)?
It is classified as a carcinogen
Which of the following is not true of glutaraldehyde?
They are always part of plasmids.
Which of the following is not true of transposons?
They can detect RNA in cells.
Which of the following is not true of vectors?
Separate DNA fragments with gel electrophoresis
Which of the following is the second step in gene mapping?
Exposing a microbe to a hypertonic environment draws water out of the cell, causing plasmolysis.
Which of the following is true regarding the use of osmotic pressure as an antimicrobial agent?
Bacterial endospores
Which of the following microbial forms has the highest resistance to physical and chemical controls?
Protozoa
Which of the following microorganisms would find hypotonic conditions most damaging?
All of the above have been shown to enhance biofilm elimination
Which of the following phrases reflects an effective treatment of biofilms?
Surface structures for attaching to tissues.
Which of the following properties is likely to be found in a pioneer colonizer of a biofilm on an artificial joint implant?
Tissue plasminogen activating factor - stimulates blood clotting
Which of the following recombinant DNA technology products is mismatched?
Salting of meat
Which of the following represents the use of osmotic pressure as a microbial control method?
Endocytosis
Which of the following require the cell to use energy?
All organisms use metabolic pathways to synthesize the 20 amino acids necessary for protein synthesis using precursors from catabolic processes.
Which of the following statements is false regarding amphibolic pathways?
Isoniazid
Which of these drugs has the most narrow-spectrum activity?
The growth of microbes in food depends on their optimal growth temperature; some grow slowly and others faster.
Which statement is correct regarding microbial growth on food at refrigeration temperatures?
Gene is amplified by multiplication of cloning host
Which step in gene mapping can occur even more rapidly by PCR?
CLONING HOST RECEIVES PLASMID
Which step in gene mapping involves transformation?
Thermoduric
Which temperature range groups contain organisms involved in food spoilage
do both prokaryotes and eukaryotes have ribosomes?
YES just larger in euks
Fermentation
You have a tube of nutrient broth, in which E. coli is growing. Upon analyzing the broth chemistry, you find: -oxygen content has dropped a bit, but carbon dioxide has gone up a lot -formic, acetic, and lactic acids are present ***What kind of metabolism has most likely occurred?
The drug might be broken down in the patient's body before it can have its full effect on the bacterium.
You have given a dosage of an antibiotic to a patient for his infection, but the patient is not getting better. The MIC tests shows that the drug that you prescribed, at the dosage that was given, should work against this particular strain of bacteria. What do you think might be the problem?
Use a pressure cooker to sterilize the bottles with steam
You have inherited some old glass baby milk bottles from your grandmother, and you would like to use them instead of plastic bottles. The bottles are placed into a large metal container and placed in the oven at 325oF for about 2 hours. What factor would you change if you wanted the sterilization to occur much quicker?
You forgot to label the probe sequence with a reporter molecule.
You have made a specific DNA probe that will bind to a key sequence on the DNA of Neisseria gonorrhoeae, allowing your company to market a gonorrhea test kit that can be used to identify the bacterium in genital tract specimens. However, upon testing it out against a known Neisseria gonorrhoeae culture, you find that it does not work. Which of the following is a possible explanation for this negative result?
The lids of the Petri dishes were inadvertently left on while being sterilized.
You have some old plastic Petri dishes that you would like to use for pouring bacteriological agar plates. The only method of physical sterilization is ultraviolet radiation sterilization with your UV light (you cannot use the autoclave because it will disfigure and melt the plastic). After sterilizing the plates, pouring the sterilized agar medium, and then leaving the plates out at room temperature for a day or two to let them solidify and dry, you find contaminating bacterial colonies growing on the agar. Predict what has happened in this situation
What has happened is the cells of E. coli were Hfr cells.
You have taken E. coli strain A which has its own plasmids, and mixed it with E. coli B strain without plasmids. E. coli B cells now have plasmids but, in addition, they also carry some genes from E. coli A strain.
E. coli does not grow because it has been dehydrated by the honey.
You want to experiment with microbial growth in various nutrients so you can inoculate a loopful of E. coli into a tube of honey. Which statement best describes what you expect to happen and why?
exoenzymes
Your bacterium is growing on a type of medium called casein agar, which contains milk protein (casein). There is a clear zone around the growth area of the bacterium, showing that it is synthesizing the enzymes needed to catalyze the breakdown of casein. These enzymes are considered
The steroid was contaminated at the production plant, so multiple batches of that drug made at that plant were contaminated with that bacterium.
Your friend Joe recently visited the doctor for steroid injections into his knee to reduce swelling due to a previous knee injury. Within a couple of days, he had an infection caused by Pseudomonas, a very pathogenic and drug resistant bacterium. Luckily, Joe went to the doctor immediately and received antibiotics. The doctor tells him that the same problem has occurred to many other people across the United States. Predict the most likely cause of this situation.
A. gene therapy
Your infant has been diagnosed with severe combined immunodeficiency disease (SCID). Your doctor suggests which treatment as a possible cure for the disease? A. gene therapy B. genome mapping C. reverse transcription D. microarrays
Ultraviolet
____ radiation excites atoms to a higher energy state within molecules such as DNA, which leads to the formation of pyrimidine dimers.
temp and pH
_____ and ____ are factors that are not time that play into efficacy of antimicrobial methods
plaque (streptococcus), ferments, acid
_____ attaches to teeth to form a biofilm that _______ sugar for nutrition and makes ____ which degrades enamel
Filtration
_____ is a control method that removes microorganisms rather than inhibiting or killing them
Silver nitrate
_____ solution was introduced in the late 19th century for preventing gonococcal infections in a newborn's eyes after exposure to the mother's infected birth canal.
Thermophile
a bacterium or other microorganism that grows best at Above 45 C best at 50
Epidemic
a big increase in either morbidity (more people becoming sick with it) or mortality (more people getting killed by it) associated with an infection Localized within a country/continent Happen frequently Can occur with foodborne disease, person to person Ex: recall on beef bc E.coli contamination, cholera
rejection of a foreign skin graft is an example of
a cell-mediated immune response
C5a can also act as what?
a chemotaxin
operon
a group of genes that operate together
microaerophiles
a microorganism that requires oxygen to survive, but requires environments containing lower levels of oxygen than are present in the atmosphere
why do you need to get the flu shot every year
a persons immune protection from vaccination declines over time, so annual vaccination is needed to get the optimal or best protection against the flu different strains
An aquatic microbe that can grow only near the surface of the water is probably which of the following? A) a phototroph B) a heterotroph C) a chemotroph D) a lithotroph E) an anaerobe
a phototroph
Which of the following statements regarding mutations is TRUE?
a prototroph can grow on glucose-salts media
The protein product of the lacI gene is
a regulatory protein.
open reading frame
a sequence of DNA that encodes protein defined by a start and stop codon
bactericide
a substance that causes the death of bacteria
germicide
a substance that destroys microorganisms
The electron carrier proteins in the electron transport chain shuttle electrons to
a terminal electron acceptor
Formation of glycosidic bonds between carbohydrate monomers to synthesize polysaccharides would be called a. anabolism b. phosphorylation c. fermentation d. exergonic e. glycolysis
a. anabolism
The _______ hypothesis states that energy released during the movement of electrons through the electron transport chain is used to generate a proton gradient (proton motive force of PMF) across the membrane, which can then be used to generate ATP through oxidative phosphorylation a. chemiosmotic b. osmolytic c. chemical d. chemotrophic e. chemolytic
a. chemiosmotic
During which of the phases of cellular respiration is the majority of ATP formed? a. electron transport b. Krebs cycle c. glycolysis d. processing of pyretic acid for the Kreb's cycle e. all phases produce the same number of ATP molecules
a. electron transport
As an RN, you are familiar with enzymatic reactions and you know that when enzyme action stops due to a buildup of end product, this control is called a. feedback inhibition (negative feedback) b. competitive inhibition c. enzyme induction d. enzyme repression e. none of the choices is correct
a. feedback inhibition (negative feedback)
Which of the following processes is common to fermentation, anaerobic respiration, and aerobic respiration? a. glycolysis b. the Kreb's cycle c. the electron transport system d. glycosylation
a. glycolysis
Based upon information in Chapter 8 and the case study, it appears that multidrug resistant strains of bacteria such as A. baumannii:
acquired their resistance genes from other bacteria in healthcare facilities
The energy released during the reactions of glycolysis is used to form _____.
adenosine triphosphate
process by which microorganisms attach themselves to cells is
adhesion
Passive immunity
administration of preformed antibodies immediate protection serum used for passive immunizations is called antiserum serum traditionally taken from people who have been previously exposed or from rabbits exposed
advantages and disadvantages of culturing viruses in tissues
advantage: Can define eclipse, latent, and rise periods Burst size is magnitudes larger bc volume of host cell is much larger than bacterial host which provides larger supply of materials to build virions disadvantage: Virus replication is usually longer (hours/ days)
advantages and disadvantages of culturing viruses in whole animals
advantage: Ensure virus strain maintains original virulence (ability to cause disease) disadvantage: Expensive and laborious involving large scale use of animals
what are some properties of streptococcus pneumoniae?
aerobic gram positive diplococcus encapsulated -leads to slimy growth on blood agar
nature of bacteria capsules
affects the virulence of these bacteria
regulatory RNA and mechanism: small RNA
after transcriptions, binds to complementary sequences located within target mRNA transcript Can stim/ prevent translation or after degradation by preventing base pairing and fold mRNA to expose to RNase
who does the CDC recommend get vaccinated with gardasil (HPV vaccine)?
all kids who are 11 or 12 years old 2 shots 6-12 months apart over 14= 3 shots over 6 months 9-26 with immunocompromising conditions: 3 shots young women through age 26, young men through age 21 young men who have sex with men through age 26 young adults who are transgender through age 26
Acinetobacter baumannii may have acquired resistance to multiple antibiotics through
all of these
transcriptome
all the RNA molecules transcribed from a genome
what are inherited small functionally insignificant structural differences between the antibodies?
allotypes
Phase variation is a phenomenon used by some bacteria (such a E. coli) to evade host immune mechanisms. In this process, the cells
alternately turn genes on/off to adjust bacterial behavior
ways gene expression can be controlled
alternation of DNA sequence, control of transcription/ mRNA stability, translational and post translational control
what are the consequences of MHC activation?
always bad for pathogen! 1. virus infected cells are killed 2. macrophages are activated to kill bacteria 3. b cells are activated
Endemic disease
always going to be present at some level in the population, normally occurs, not a ton of cases, may occur continually, or something that occurs every winter, stable incidence, occurs regularly within population Prior to vaccination- chickenpox
constitutive expression
always present because essential to cell and always needs it
what is sometimes the only effective treatment of life threatening infections?
amphotericin and steroids (if serious resp involvement)
The plasmid is mobilized for transfer when
an endonuclease cleaves it at the origin of transfer
The rate of growth in flask 2 is substantially faster than that in flask 1, but somewhat slower than that in flask 3. You detect the production of nitrite. The E. coli in this tube can be most accurately described as undergoing ______.
anaerobic respiration
what is the term for when bacteriostatic effect of one antibiotic reduces the bactericidal effect of the second antibiotic?
antagonism
which drug category is antimicrobials of microbial origin, produced by fungi or by soil bacteria, used in the treatment of infectious disease?
antibiotics
a direct fluorescent antibody test requires what
antibodies against the antigen
humoral immunity
antibody mediated, to get antibodies, start out with B cells and those become activated to become plasma cells which secrete antibody- particularly helpful for extracellular invaders, can also help with intracellular when outside of cell, good for neutralizing toxins (tetanus)
what is a serum protein that binds specifically to antigen and brings about the remove of an offending foreign substance?
antibody/immunoglobulin
what is a foreign material that is specifically bound by antibody of lymphocytes?
antigen
When antigen and antibodies combine, maximal precipitation occurs when
antigen and antibody are at equivalent concentrations
broad spectrum
antimicrobial that works against *many* different kinds of pathogens
narrow spectrum
antimicrobial that works against only a *few* kinds of pathogens
which category of drugs is any substance with sufficient antimicrobial activity that can be used in the treatment of infectious diseases?
antimicrobial, antimicrobic
antigen
anything adaptive immune system recognizes, anything immune system can react to or respond to Our cells have antigens on their surface, pollen has antigens on its surface, microbes have antigens on their surface Any pathogen you encounter likely to have multiple antigens on it, one or few are dominant antigen that immune system will respond to
paralogs
arise by gene duplication, genes diverge and acquire new functions
vector transmission
arthropods that transmit diseases biological or mechanical
Picornavirus-Poliovirus As much as 72-90% of infections are ___________ The majority who had symptoms (about 90%) were sick for about ________ (fever, headache, sore throat, vomiting), some progressing to meningitis but all recovered completely. About 1% of all infections had ____________. They appeared to get better but polio traveled through the nerve cells to the brain and symptoms of paralysis occurred. Most just had limb involvement but about 20% also had weakness of muscles involved in swallowing and breathing -they did much worse (with 25-75% mortality- don't need to know these numbers). Most recovered the use of their limbs but some were __________ for life.
asymptomatic week paralytic poliomyelitis paralyzed
A microorganism grows in the lab on medium containing mineral salts but no organic compounds. The organism is likely to be a(n) A) heterotroph. B) autotroph. C) chemotroph. D) chemoheterotroph. E) The answer cannot be determined from the information provided.
autotroph.
Reactants are converted to products by a. enzymes releasing energy b. breaking and forming bonds c. enzymes binding to reactants d. reactants releasing energy e. none of these choices is correct
b. breaking and forming bonds
The breakdown of peptidoglycan to N-acetylmuramic acid, N-acetylglucosamine, and peptides are an example of a. anabolism b. catabolism c. phosphorylation d. fermentation e. synthesis
b. catabolism
ATP is composed of deoxyribose, adenine, and 3 phosphate groups (T/F) a. true b. false
b. false
ATP molecules are catalysts that lower the activation energy needed to initiate a reaction (T/F) a. true b. false
b. false
During aerobic cellular respiration, the final electron acceptor is a. pyretic acid b. oxygen c. nitrate d. cytochrome c e. FAD
b. oxygen
Which of the following macromolecules, when catabolized, COULD release carbon, sulfur, and nitrogen a. nucleic acids b. proteins c. carbohydrates d. lipids e. all of the above could release carbon, sulfur and nitrogen
b. proteins
/C. difficile/
bacteria; frequent cause of superinfections; patients in hospital sometimes develop this diarrhea-causing infection after treatment with antibiotics; leads to pseudomembranous colitis in severe cases
CRISPR
bacterial adaptive immune defense system clustered regularly interspaced short palindromic repeats
restriction and modification system
bacterial innate immunity defense systems enzymatic cleavage of alien DNA and protecting its own DNA via methylation modification
what is the ability of drugs to kill a microorganism? is it reversible?
bactericidal not reversible
A virus that infects bacterial cells is called a ______.
bacteriophage
what is the ability of drugs to inhibit the growth of a microrganism? is it reversible?
bacteriostatic is reversible
how are fungi named differently?
based on sexual or asexual reproduction
which leukocyte releases histamine to help initiate the inflammatory response?
basophils
which cell has IgE receptors and releases heparin, histamine, and %-hydroxytrpyamine? what is its action?
basophils-found in the blood 1. amines increase vascular permeability 2. allow inflammatory cells and complement to enter tissue from the blood
why is fungal treatment difficult?
because both fungi and humans are euks can harm humans in the process of treatment-can be toxic
clonal expansion
because it is specific for such tiny little things, you have lots and lots of different cells that respond to different things, because you have such diversity, can't have a lot of copies of any one of those until it becomes activated, once it recognizes specific antigen, then undergo clonal expansion gets lots of copies of that particular immune cell
Why are capsules sometimes considered virulence factors?
because many capsules are composed of chemicals normally found in the body; as a result, they do not stimulate a host's immune response anti-phagocytic help bacterium to avoid being phagocytized-slippery
How can members of your normal microbiota become pathogens?
become opportunistic pathogens introduction of a member of the normal microbiota into an unusual site in the body immune suppression changes in the amounts you have microbial antagonism or microbial competition diminishes, if a normal bacteria microbiota is killed by antimicrobial treatment another normal bacteria microbiota may grow prolifically (yeast infection) stressful conditions (disrupt metabolism or emotional state, or exposure to overwhelming numbers of pathogen)- hormone changes
chemotherapy began as a science in what century and who discovered it?
began in the early 20th century paul ehrlich: founder of modern chemotherapy
where does your normal microbiota come from?
begins to develop as soon as your amniotic membrane ruptures; you come into contact with microorganisms during birth, your first breath, your first meal, the second someone touches you continue to add and subtract from your transient microbiota most of resident microbiota was initially established during your first months of life
Toll-like receptors (TLRs) act to
bind microbial proteins and polysaccharides
riboswitch during transcription
binding ligand prevents termination and coding region expressed
Sigma factors are responsible for
binding of RNA polymerase to consensus sequences on DNA
role of CII protein in molecular regulation of the switch from lysogenic to lytic growth in viruses
blocks Cro and leads to lysogeny
What does tetracycline do?
blocks binding of aminoacyl-tRNA to A site
bodily fluid transmission
blood, urine, saliva, and other bodily fluids when handled by healthcare workers (vehicle transmission) ex: AIDS, hepatitis, herpes ex: HIV via sexual intercourse
where do b cells originate?
bone marrow
MacConkey agar plates represent ________ medium. A) a minimal B) a selective C) a differential D) both a differential and a selective E) both a minimal and a selective
both a differential and a selective
The trp operon is regulated by
both a repressor protein and attenuation
mutualism
both symbionts benefit from their interaction ex: bacteria in colon ex: termites and wood-digesting protozoa and bacteria living in their intestines ex: oxpeckers and zebras
Early in glycolysis, two phosphates are added to the glucose molecule. These phosphates come from
breaking down ATP
how are isotype classes determined?
by its Fc portion (constant region, heavy chain)
Allovibrio fischeri produces a luminescent protein but only when a threshold number of these cells are present. This occurs because the bioluminescent protein is induced
by quorum sensing of an autoinducer produced by all cells present and allowing persistence and activation of the operon.
how do phagocytes recognize invading microorganisms? where was this receptor discovered?
by toll like receptors discovered in fruit flies
Enzymes that catalyze removal of carbon dioxide from a substrate are called a. phosphotransferases b. oxidoreductases c. decarboxylates d. aminotransderases e. ligases
c. decarboxylases
As the electron transport carriers shuttle electrons, they actively pump _____ into the outer membrane compartment setting up a concentration gradient called the proton motive force a. ATP b. phosphate c. hydrogen ions d. oxygen e. NADH
c. hydrogen ions
The formation of citric acid from oxaloacetic acid and an acetyl group begins a. glycolysis b. the electron transport system c. the Kreb's cycle d. fermentation e. oxidative phosphorylation
c. the Kreb's cycle
which protein acts as an opsonin?
c3b neutrophils and macrophages phagocytose bacteria more aggressively with activation of C3b
examples of second messengers
cAMP, ppGpp, cyclic di-GMP, cGMP
which is a gram negative rod that has bipolar flagella that is an opportunistic pathogen for people with HIV/AIDS?
campylobacter chickens can develop a life long carrier state cause abortions in cattle or sheep
Antigenic variation is a phenomenon used by some bacteria (such as Neisseria gonorrhoeae) to evade host immune mechanisms. In this process, the cells
can change the characteristics of certain surface proteins on the bacteria, forcing immune response to constantly adapt
what type of flu shot is safest for a person who is allergic to eggs? Can a person who is allergic to eggs receive a regular flu shot?
can get any but need to get at medical facility if severe flucil vax has little egg cell-based has no egg
When the bacteriophage transfers bacterial DNA into a recipient bacterial cell, that DNA
can integrate into the chromosome
facultative anaerobes
can live with or without oxygen. Prefers aerobic but can switch to fermentation
advantages of attenuated vaccines
can result in mild infections but no disease replicating microbes stimulate a strong immune response immune system is designed to fight off things that are replicating (otherwise fights off things like pollen) viral vaccines trigger a cell-mediated immune response (TH1 and cytotoxic T cells) attenuated viruses are going to infect cells and be seen as a virus, trigger t helper 1 response activating cytotoxic T cells Vaccinated individuals can infect those around them (contact immunity) only certain vaccines ex: cow pox virus for small pox, less severe diseases ex: MMR
inhibition protease of antiviral drug
can stop premature virus leaving cell and becoming mature HIV infections
phage genome integrated into a host genome.
can undergo lysogeny.
no
can you sterilize skin
structure and its function in phage lambda (4)
capsid: icosahedral, protects viral genome viral genome: dsDNA that performs key functions such as integration, DNA replication, lysis, lysogeny sheath: unlike T4, doesn't contract to deliver genome, travels down tube to base plate then injects DNA tail fibers: helps phage attach to host cell
A capnophile is a microorganism that thrives in conditions of high A) carbon dioxide levels. B) hydrostatic pressure. C) oxygen levels. D) pH. E) salt concentration
carbon dioxide levels.
Catalytic RNA
carries out enzymatic reactiona
Bacteriocin plasmids
carry genes for proteinaceous toxins called bacteriocins which kill bacterial cells of the same or similar species that lack the plasmid
Virulence plasmids
carry instructions for structures, enzymes, or toxins that enable a bacterium to become pathogenic
nutrients, precursors
catabolism= __________ -> _____________
stringent response
causes decrease in # rRNA transcripts made for ribosome assembly and alters expression of other genes
macromolecules, cell structures
cell growth = ___ -> ___
which type of adaptive immunity requires direct contact of the antigen with lymphocytes?
cell mediated immunity interaction with t cells
what is the best way to deal with intracellular organisms like viruses and bacteria? what is the best way to deal with extracellular organisms?
cell mediated immunity: intracellular humoral immunity: extracellular
energy and carbon source
chemoautotroph photoautotroph chemoheterotroph photoheterotroph is grouped by
what is the vehicle by which hereditary info is physically transmitted from one generation to the next?
chromosome
which chromosome codes for MHC?
chromosome 6
Giardia intestinalis
clinical features: leading intestinal parasite incubation period: 1-3 weeks symptoms: diarrhea, bloating, cramps, fatigue treatment: chemotherapy (metronidazole)
Helicobacter pylori
clinical features: most infections asymptomatic, stomach ulcers, cancers: stomach cancer, gastric lymphoma characteristics: gram (-) bacteria, spiral shaped, highly mobile, displays high interstrain diversity, major species causing human diseases, produces large amount of urease to neutralize stomach acid symptoms: pain, bloating, lack of appetite, nausea, vomiting, dark/tar colored stool transmission: currently unknown diagnosis: blood test for antibodies, urea breath test, biopsy combined with urease test and histological exam treatment: triple therapy - antibiotics amoxicillin and clarithromycin - proton pump inhibitor such as omeprazole Barry Marshall (drank cultured Helicobacter) and Robin Warren
Entamoeba histolytica
clinical features: parasite common in tropical areas with poor sanitary conditions incubation period: 2-4 weeks symptoms: often mild and can include loose stools, stomach pain, and stomach cramping. Amebic dysentery is a severe form treatment: chemotherapy (metronidazole, paromomycin) complications: liver abscess and intestinal blockage
which bacteria is a gram positive, spore forming rod that resides in intestines as normal flora, but overgrowth can lead to disease? what symptoms would one experience with overgrowth?
clostridium difficile watery diarrhea (15 times a day), abdominal pain, and tendernes, blood in stool
Psychrophiles
cold loving bacteria, thrives below 15C, can grow at 0, dies at 20C
Endogenous nosocomial infection
common, arise from normal microbiota due to factors within the health care setting, wind up in places they shouldn't be or you are so immune suppressed that they end up causing problem (ex: staph aureus) Iatrogenic- results from modern medical procedures (ex: urinary catheters frequently cause UTI)
gram negative bacteria transforms DNA without
competence factors, transformasomes either always competent or they become competent when starved
classical pathway of complement activation
complement binds to an antibody that is bound to a foreign substance. activates C3a and C5a this produces peptide mediators for inflammation and phagocyte recruitment
mosaic gene
composed of alternating sequence polymorphisms either belonging to the host original allele or derived from the integrated donor DNA identification of mosaic genes and detection of corresponding partial (HGT)
What is the likely way other bacteria might acquire the mcr-1 gene?
conjugation
Because all of the genes coding for antibiotic resistance have been found to come from other organisms, A. baumannii most likely acquired them through
conjugation or a similar process of genetic exchange
The first step in conjugation is
contact between the donor and recipient
Limitations of Antisera
contain antibodies against many different antigens not just the ones of interest from other animals- antibodies don't match- can have a reaction if multiple doses repeated injections of antisera collected from a different species can trigger allergic reactions antisera may be contaminated with viral pathogens antibodies of antisera are degraded relatively quickly many of these limitations have been overcome through the development of hybridomas- antibodies in lab that don't have rabbit parts, viral pathogens
granulocytes
contain large granules that stain different colors 3 types basophils- involved in inflammation, 0.5-1% eosinophils- involved in fighting worm infection, 2-4% neutrophils- important for phagocytosing pathogens, sound alarm when there is infection, trigger inflammation and things like that, 60-70%, most prevalent white blood cell
UV light and other non-ionizing radiation damage DNA molecules by
creating thymine dimers between adjacent thymine nucleobases in the DNA chain
defined media
culturing media of which the exact chemical composition is known
complex media
culturing media that consists of nutrients released by the partial digestion of yeast, beef, soy, or other proteins - the exact chemical compostion is unknown
selective media
culturing medium containing substances that either favor the growth of particular microorganisms or inhibit the growth of unwanted ones
which molecules of innate immunity stimulate adaptive immunity?
cytokines/chemokines interleukins colony stimulating factors (erythropoietin- made in kidney, stimulates RBC production) tumor necrosis factor tumor growth factor (wound healing)
The TCA (Krebs) Cycle takes place in the mitochondria of eukaryote cells. Where does it take place in prokaryote cells?
cytoplasm
Where does the TCA Cycle take place in bacteria?
cytoplasm
Microorganisms often grow on more complex molecules than glucose. Sometimes these nutrition sources are lipids. However before the lipid can be metabolized, its fatty acid side chains must be broken down by the _________ cycle to Acetyl-CoA a. tri-carboxylic acid b. citric acid c. glyoxylate d. B-oxidation e. reductive tai-carboxylic acid
d. B-oxidation
All of the following pertain to glycolysis except it a. occurs without oxygen b. ends with formation of pyretic acid c. occurs during fermentation d. degrades glucose to CO2 and H2O e. involves reduction of NAD
d. degrades glucose to CO2 and H2O
define retroelements of ancient retroviral sequences present in the human genome
decaying genomes Retains all genomic elements of retrovirus
A sample of E. coli has been subjected to heat for a specified time, and 90% of the cells have been destroyed. Which of the following terms best describes this event?
decimal reduction time
A laboratory recipe lists sucrose, an ammonia compound, calcium salts and a buffer as the ingredients for a microbiologic medium. These are added to water and autoclaved. What type of medium does this protocol produce? A) defined agar B) defined broth C) complex broth D) reducing agar E) complex enrichment broth
defined broth
components involved in protein degradation- proteolysis
degrons: degradation signals that dictate stability of protein proteases: protein to peptide peptidase: use ATP hydrolysis to help unfold the target protein prior to digestion, peptide to amino acids ubiquitin: marker for target proteins
phagocytes of the epidermis are called
dendritic cells
what are cells with long membrane extensions that are responsible for phagocytosis?
dendritic cells
the microbial death rate is used to measure the efficiency of...
detergent, antiseptic, sanitization techniques
acute disease
develops rapidly, lasts a relatively short time ex: common cold
which type of fungi can grow in morphologically two distinct forms?
dimorphic/ systemic fungi as mold form and yeast form depends on temperature
asymptomatic disease
disease without symptoms ex: STD infection, ulcers disease
zoonoses
diseases that spread naturally from animal hosts to humans over 200 ex: anthrax, bubonic plague, rabies, ebola
what kills microorganisms on laboratory surfaces?
disinfectants
how are molecules held together in the antibody structure?
disulfide bonds
granulocytes
don't appear to have granules cytoplasm appears uniform under a light microscope 2 types lymphocytes- most involved in adaptive immunity, B and T cells, natural killer cells in innate monocytes- mature into macrophages- important for phagocytosing microbes and helping to trigger immune response in adaptive immune system
genome analysis of viruses
don't have rRNA but can be compared based on orthologs
Viral genomes may comprise
double or single-stranded DNA or double-stranded RNA.
biosafety Level 3 includes
doubles sets of entry doors (no showers in entry ways, no pressurized suits)
virustatic
drug that inhibits the growth of viruses
antiviral drugs
drugs that neutralize the acidity of phagolysosomes prevent viral uncaring nucleotide analogs can be used to stop microbial replication drugs containing protease inhibitors retard viral growth by blocking the production of essential viral proteins (FALSE: macrolide drugs block attachment sites on the host cell wall and prevent viruses from entering)
dessiccation
drying out, preservation of food, non sterile
which of the following types of radiation is more widely used as an antimicrobial technique
electron beams
function of mRNA
encodes proteins
what is a fungal infection that is restricted geographically that can cause serious disseminated infection in healthy individuals?
endemic/ systemic mycoses example: histoplasmosis in tropical regions ( classified as ascomycota)
where is MHC I and II assembled?
endoplasmic reticulum
A fastidious organism might be grown on which of the following types of media? A) transport media B) reducing media C) enriched media D) differential media E) selective media
enriched media
Joan wants to discover a microbe capable of degrading an environmental contaminant. Which of the following culturing methods would be most effective for isolation of such an organism? A) cell culture B) chemostat C) quorum sensing D) enrichment culture E) differential culture
enrichment culture
Creating conditions in the laboratory that promote the growth of some microbes while inhibiting the growth of others is called A) complex culturing. B) reducing conditions. C) enrichment culturing. D) transport conditions. E) differential culturing.
enrichment culturing.
what is a close relative of streptococcus?
enterococcus
which is implicated in hospital acquired infections?
enterococcus faecalis
Generalized infection in infants Happens if the mother has an __________ infection during last week of pregnancy/or newborn gets enteroviral infections shortly after birth. If the baby gets an enterovirual infection (many enteroviruses can cause this) the infections can spread to __________ and cause death of the infant. Just like polio if the mother can have a chance to from antibodies and transfer them to the fetus the baby will be ___________ from virus spreading in the blood to target organs.
enteroviral multiple organs protected
Aseptic
environment free of pathogens
Factors affecting efficacy
environmental conditions, how susceptible the things are that you are trying to kill, germicide effectiveness levels, population size, concentration or intensity of treatment, duration of exposure, age of chemical
Consider the image you labeled showing a metabolic pathway under allosteric regulation. Which enzyme in this pathway is most likely under allosteric control?
enzyme a
Exoenzymes
enzymes secreted by cell that break down and inflict damage on tissues for disease spread of food
DNA restriction endonucleases
enzymes that recognize specific short DNA sequences and cleave DNA at or near sequences
which leukocyte is present in large numbers during allergic reaction and worm infection?
eosinophils
which cell is increased in number in infections due to parasites/worms and allergic reactions? which immunoglobulin is present on its surface?
eosinophils surface: IgE exit through blood vessel wall into tissue
which WBC have IgE receptors?
eosinophils basophils mast cells
propagated epidemic
epidemics result from person-to-person contact, take more time to see a lot of cases, can be harder to control, eventually it will go down, figure out how to isolate people, harder to get rid of ex: influenza
pandemic
epidemics that occur across multiple continents Diseases that are spread person to person bc air travel Ex: respiratory transmitted diseases
what is the area on the peptide on which the antigen resides?
epitope epitope = hapten + macromolecule
what is the fungal membrane made up of? what are most mammalian membranes made up of?
ergosterol : fungi cholesterol: mammals
what chemical is active against bacterial endospores?
ethylene oxide
which antimicrobial chemical has been used to sterilize spacecraft
ethylene oxide
Which of the following statements regarding transcription and translation is TRUE?
eukaryotes must splice out introns following transcription, while prokaryotes do not
MHC class II molecules bind to _____ and trigger _____
exogenous antigens; helper T cells
T/F: An enzyme speeds up a chemical reaction in the cell, but can only be used once.
false
T/F: Chemical agents can cause mutations by inducing ethylation of guanine residues in DNA.
false
T/F: In prokaryotes and eukaryotes, the TCA Cycle takes place in the mitochondria.
false
T/F: Nosocomial infections caused by A. baumannii in civilian hospitals are not a major concern.
false
T/F: The entire genome of the donor cell is usually transferred to the recipient cell.
false
Intramuscular injection
fast, gets a higher concentration of drug into body than with oral, don't worry about stomach acid or absorption, not as high as concentration with IV, into system faster than pill
Picornavirus-Rhinovirus a picornavirus but cannot be transmitted by the _______________. __________ inactivate the virus. The virus prefers to grow at _______ which makes it ideal for the upper respiratory tract. There are over ______ different serotypes the major cause of the ______________ like other naked viruses, the virus can stay infectious on ___________ for several hours. Can excrete high amounts of virus in ____________ ___________ is thought to be a major rout of infection
fecal/oral route Low pH's 33° 150 common cold. surfaces nasal secretions Hand to face
flagellar tumbling
flagella are splayed out while rotating in a clockwise direction, creating a looping motion and preventing meaningful forward movement but reorienting the cell toward the direction of the attractant.
anti-human antibody antibodies are
formed by animals reacting to human immunoglobulins
A culture of E.coli is irradiated with UV light affects the cell's DNA by
forming covalent bonds between thymine bases on the same strand of DNA
what happens if there is an accumulation of antibody-antigen complexes?
forms precipitating complexes, can damage normal tissue can result from defective phagocytosis
what did paul want?
founder of modern chemotherapy wanted selective inhibition: kill microbe, not the host
aseptic
free of contamination by pathogens
tmrna
free ribosome stuck on damaged mRNA
multiple-drug resistant microbes
frequently develop in hospitals
the Irish potato famine was caused by which microorganism?
fungi Phytophtora infestans lead to disease caused late blight (decay of stem, leaves, and tubers)--caused 10 billion dollars in economic loss per year also cause disease in tomato if all the crops died by fungal disease, 61% of the worlds population would not have food the population of Ireland decreased by 25%
the type of interferon present late in an infection is
gamma interferon
Adenovirus dsDNA, Naked, Icosahedral type-40, 41 associated with gastroenteritis Incubation 8 to 10 days most do not cause ____________
gastroenteritis
In infants rotavirus is the most common cause of serve _______________ in the US and the world
gastroenteritis
how do protein superfamilies form
gene duplication arise from divergent reactions
lytic cycle
generates large number of progeny phages and then lyses cell
constant
generation is _____ in Log phase
The ________ of a population is the time it takes for the cells to double in number. A) binary fission B) exponential growth C) generation time D) arithmetic growth E) log phase
generation time
Which of the following statements regarding bacterial gene control is FALSE?
genes for constitutive enzymes can be turned on and off as necessary
animal and plant viral defenses
genetic resistance: mutations immune system RNA interference
Which of the following is LEAST subject to change in the cell?
genome Although the genome is subject to phase variation, it is the most stable of the omes. The transcriptome changes as different genes are expressed. The proteome changes frequently as different genes are transcribed and translated.
Glycolysis is the central metabolic pathway that involves the breakdown of _______.
glucose
The lac operon is expressed when
glucose is low and lactose is present
describe replication of influenza
goes (-) RNA strand to make (+) RNA strand using RNA dependent RNA polymerase then DNA
streptococcus is gram ____________________ and catalase ___________
gram positive catalase negative
staphylococci is gram ___________ and catalase __________
gram positive catalase positive also coagulase positive
what are some properties of staphylococci?
gram positive cocci CATALASE POSITIVE!!! coagulase positive
Catalase
gram positive identifier
Neutrophiles
grow best in a narrow range around neutral pH of 6.5 and 7.5
Acidophiles
grow in acidic environments as low as 0.0
microbial growth
growth of a population
sigma factor
guides RNA pol to beginning of genes
chemical methods of microbial growth
halogens, heavy metals, oxidizing agents, phenols, surfactants, aldehydes, alcohols, gaseous agents, enzymes, antimicrobials
what is the 2nd degree response to antigen
happens after the second exposure to antigen is quicker - 1 to 3 days makes more IgG than IgM this is more specific (affinity maturation)
what is an antigen that is too small to generate an immune response on its own?
hapten
The classic transformation experiment done by Griffith used
harmless and virulent strains of Streptococcus pneumoniae
a positive tuberculin skin test indicates that a patient not immunized against tuberculosis
has been exposed to tuberculosis antigens
How does aminoacyl-tRNA synthetase charge tRNA
has specific binding site for cognate amino acid and site to recognize target tRNA 1 aminoacyl-tRNA synthetase per amino acid (20)
Composite transposons
have 2 duplicate insertion sequence elements that flank additional genes Often interior inverted repeated of these elements contain mutations
How do you become immune to something?
have initial exposure, immune system mounts an effective response, memory cells as a result, just bc you are are exposed to something does not mean you will become immune to it, have to have an effective response naturally acquired active immunity naturally acquired passive immunity artificially acquired active immunity artificially acquired passive immunity
Type I and III DNA restriction endonucleases
have restriction and modification activities combo in 1 multifunctional protein and cleaves DNA some distance away from recognition site
what is the purpose of pilli?
helps interact and adhere to surfaces
why does cell undergo phase variation
helps microbial pathogens avoid immune system
Pasteurization
helps reduce number of pathogens present in liquids, get rid of vegetative cells that would cause spoilage or illness, ex: apple juice, milk, still go bad after a while, does not damage or harm food 3 methods batch method- 30 min at 63 C- traditional method flash pasteurization- 72 C for 15 sec, most commonly used today ultrahigh-temperature pasteurization- 134 C for 1 sec
translational control of gene expression
hides mRNA ribosome binding sites of repressor proteins coupled with transcriptional mechanisms where translation senses level of amino acids in cell and then can either +/- transcription of genes that encode enzymes to make that amino acid
which of the following are most likely to cause disease?
highly virulent organisms (NOT opportunistic pathogens in a weakened host, pathogens lacking the enzyme kinase, pathogens lacking the enzyme collagenase)
what type of macrophages are found in CT?
histocyte
what is the most common endemic mycosis in the US and in which states is it predominant?
histoplasma capsulatum states 1. ohio 2. illionois 3. missouri 4. kentucky 5. Tennessee OIMKT
function of the beta prime subunit of RNA pol
houses Mg 2+ containing catalytic site for RNA synthesis
what refers to immunity based on b cell generation of circulating antibody?
humoral immunity
The proofreading function of DNA polymerase reduces the error rate from about one in a million base pairs to about one in a _____ base pairs.
hundred million
which disease is due to genetically programmed degeneration of neurons in certain areas of the brain?
huntingtons disease symptoms: uncontrolled movement, loss of intellectual
At temperatures higher than the maximum growth temperature for an organism A) proteins are permanently denatured. B) membranes become too fluid for proper function. C) hydrogen bonds within molecules are broken. D) hydrogen bonds are broken and proteins are permanently denatured. E) hydrogen bonds are broken, proteins are denatured, and membranes become too fluid.
hydrogen bonds are broken, proteins are denatured, and membranes become too fluid.
what would most effectively inhibit anaerobes?
hydrogen peroxide
describe reassortment of influenza
if 2 different strains of influenza infect a host then segments can reassort to make novel hybrid strain antigenic shift where very different strains evades hosts such as ducks to humans
how susceptible the things are that you are trying to kill
if youre just concerned with killing vegetative bacteria (normal state) you don't have to have something super strong- most gram neg and pos bacteria are pretty susceptible to antimicrobials if you have a spore forming bacteria you need a much stronger chemical or much higher temp to get rid of it prions and bacterial endospores are particularly hardy and hard to get rid of Cysts of protozoa (ex: cryptosporidium) pretty hard
food poisoning
illness caused by bacteria or other toxins in food, typically with vomiting and diarrhea; common causes include /S. aureus/, /Listeria monocytogenes/, and /E. coli/
many different proteins in serum can be analyzed by a (an)
immunodiffusion test
where are transposons located?
in plasmids (extrachromosomal DNA) plasmid can be circular or supercoiled can have more than one plasmid per cell can have more than one copy of the plasmid per cell
how does sigma factors help control gene expression
in response to given environment, microbes will increase synthesis or decrease destruction of appropriate sigma factor Cell redirects RNA pol to promoters of genes best suited for growth/ survival in new environment
correct sequence of events in infectious disease
incubation, prodromal period, illness, decline, convalescence
role of viruses in marine ecosystem
infect most phytoplankton, releasing their minerals in the upper water, where they are available for other phototrophs.
focal infection
infection site that serves as a source of pathogens for infections at other sites in the body
secondary infection
infections that follow a primary infection; often by opportunistic pathogens
evaluate the evidence for horizontal gene transfer by parametric methods
infer HGT by computing a statistic- GC content regions with atypical values a inferred as having been horizontally transferred
what is a complex reaction to injury, irritation, or foreign invaders? what are the four characteristics of this reaction?
inflammation pain, swelling, redness, heat
what does chloramphenicol do?
inhibits peptidyltransferase
An epidemiologist is investigating a new disease and observes what appear to be bacteria inside tissue cells in clinical samples from victims. The scientist wants to try to isolate the bacteria in the lab. What culture conditions are most likely to be successful? A) culturing on blood agar plates B) inoculation of EMB plates C) incubation in an anaerobic culture system D) inoculation of cell cultures E) inoculation of a minimal medium broth
inoculation of cell cultures
Transduction
involves a virus. Accidently one of the viruses got bacterial DNA put into it instead of viral.. And it releases and attaches to a new cell, but injects bacterial DNA instead of viral DNA
food borne transmission
involves pathogens in and on foods that are inadequately processed, undercooked, or poorly refrigerated. foods may be contaminated with normal microbiota, zoonotic pathogens such as mycobacterium bovis and toxoplasma, and with parasitic worms that alternate between human and animal hosts fecal-oral route
Airborne transmission
involves spread of pathogens farther than 1 meter to the respiratory mucous membranes of a new host via an aerosol (a cloud of small droplets and solid particles suspend in the air) ex: machines create aerosols of B. anthracis spores in post office, postal worker contracts anthrax
Bacteriocidal
kills bacteria
intermediate level germicide
kills fungal spores, protozoan cysts, viruses and pathogenic bacteria, but not bacterial endospores
oxygen independent killing kills what type of bacteria? what is produced to kill?
kills gram negative bacteria cathelicidin, lysozyme, and lactoferrin: bactericidal proteins are produced defensins and phosopholipase A are produced to dissolve outer membrane (azurophillic granules release these cationic proteins)
oxygen dependent killing kills what type of bacteria? what compound is formed from this process to kill the bacteria?
kills: gram positive bacteria forms hypochlorous acid to kill
what type of macrophage is found in the liver?
kupffer cell
Genes can be lost during genomic evolution through
lack of repair to the gene when it is no longer needed large scale loss occurs as genes become pseudogenes as they are not repaired. Over time these remnants can be lost as they are not needed for normal function.
After glycolysis, pyruvate can be converted into _____ under anaerobic conditions.
lactic acid
cheddar cheese, yogurt, soy sauce
lactic acid fermentation products
When cells are metabolically active but not dividing, they are in the ________ phase. A) stationary B) log C) lag D) death E) exponential
lag
which are immature dendritic cells found in the skin and act as antigen presenting cells?
langerhan cells
gene reduction
large scale loss of genes through evolution genomes contain pseudogenes that are by homology appear to encode enzyme but are nonfunctional bc portion is missing through deletion and contain remnants of the gene
What vaccine would be most effective in preventing smallpox infection?
live attenuated vaccine no asymptomatic carriers of smallpox- key to eradicating disease if some one got small pox all contacts got vaccinated ring vaccination small pox is potential bioterrism threat
Which of the following statements about the Ames test is FALSE?
liver extract is added to provide nutrients
The generation time of bacterial cells is shortest during the ________ phase. A) death B) lag C) log D) stationary E) longitudinal
log
A _____ virus cycle leads only to cell lysis, and a _____ virus cycle involves phage genome integration into the host genome.
lytic; lysogenic
DNA techniques for improving vaccines
make an attenuated strain- go in and delete virulence gene, not just hoping it occurs naturally by culturing in harsh conditions, more thoroughly ensure that it won't revert, make more safe make a vaccine against a certain bacterium- currently used in several vaccines, isolate DNA from bacterium we want protection against, put that in yeast cell, yeast cell will synthesize a bunch of copies of antigen, used in one hepatitis vaccination not used yet- make a vaccine- take the gene encoding the antigen that you want protection against, and put into more harmless virus to put into vaccine, will express antigen on surface for more severe disease not used yet- good for viruses potentially- isolate the DNA coding for antigen you need protection against, insert into plasmid vector, use gene gun to put into persons cells, allow cells to synthesize antigen
inhibit mRNA movement
make it so that mRNA cant move through ribosome, antibiotics in class called macrolides bind to 50s subunit and make it to where mRNA cant move and makes it to where you cant synthesize anymore protein Ex: Zithromax, erythromycin Typically mostly target gram positive bacteria
methylation of DNA restriction and modification systems
makes sequence invisible to matched restriction endonuclease Only 1 strand needs to be methylated to protect from cleavage (hemimethylated)
Bacteriophage lambda binds to the ______ that is embedded in the outer membrane of E. coli.
maltose porin
MB-lectin pathway
mannose-binding lectin binds mannose on pathogen surfaces activates C3b leads to opsonization of pathogens and removal of immune complexes
exotoxins
many microorganisms secrete exotoxins that are central to their pathogenicity in that they destroy host cells or interfere with host metabolism ex: cytotoxins- kill host cells in general or affect their function neurotoxins-specifically interfere with nerve function enterotoxins- affect cells lining gastrointestinal tract
Dr. John Snow
mapped cholera cases, found contaminated water pump- father of epidemiology
which WBC is only found in tissues and releases histamine?
mast cells
microbial contaminants
may become opportunistic pathogens, may be a part of the transient microbiota, may be introduced by a mosquito bite (FALSE: most will eventually cause harm)
problems with attenuated vaccines
may cause disease immunosuppressed individuals pregnant women should not receive live vaccines- could be transmitted to fetus, immune suppressed modified viruses may occasionally revert to wild type or mutate to a virulent form (Polio)
transformation
mechanism of horiz gene transfer in which naked environment DNA is taken up by bacterial cell
transduction
mechanisms of horizontal gene transfer in bacteria in which genes are transferred through viral infection
What are the real risks associated with the NMR vaccine, and how common are those adverse effects?
minor- sore arm, fever, redness or rash, swelling in cheeks or neck moderate- seizure, temporary pain and stifness in joints, temporary low platelet count, rash all over body severe- deafness, long-term seizures, coma, lowered consciousness, Brain damage occur very rarely
Using the genetic code (below), determine what type of mutation would occur if the last nucleotide in the codon AGA was converted to a U.
missense
sickle cell anemia is an example of what kind of point mutation?
missense mutation codes for a different amino acid making it non functional HbBs is mutated
which type of plasmid can be transferred between different bacteria species? what are examples of genes found on mobile plasmids?
mobile examples: antibiotic resistance gene and virulence factors such as adhesins and toxins
attenuated vaccines
modified live vaccines attenuation= reducing virulence culture them in conditions where they normally wouldn't grow, overtime it will lose its ability to grow in cell
post translational control of gene expression
modify protein product: cleavage, phosphorylation, methylation, acetylation that activates/ destroys proteins
what are identical antibody molecules made by a clone of cells that arose from a single ab producing cell?
monoclonal antibodies (Mab)
which cell do cancer patients lack due to treatment?
monocytes
how is flu mist (LAIV) different from the flu shot
more likely to get symptoms contains live virus strong response, not a shot
alternation of DNA sequence of gene control
most drastic and least reversible uses random/ programmed changes in DNA to activate/ disable genes phase variation
In bacteria, proton pumps are protein complexes that
move protons from the interior of the cell to the exterior
slipped strand mispairing
multiple short sequence repeats within gene that confuse DNA pol as it is replicated causing it to slip occasionally and shifting reading frame and turning genes on and off
Koch's postulate
must satisfy all to prove that a given infectious agent causes a given disease can't use if it is a deadly disease that only infects humans 1) suspected agent (bacterium, virus, etc) must be present in every case of the disease 2) that agent must be isolated and grown in pure culture 3) the cultured agent must cause the disease when it is inoculated into a healthy, susceptible experimental host 4) the same agent must be reisolated from the diseased experimental host
symbiosis in which both members benefit
mutualism
which bacteria can be identified with an acid fast stain?
mycobacterium
which bacteria has a waxy cell wall?
mycobacterium
which bacteria lacks a cell wall, and requires cholesterol for growth?
mycoplasma
which spectrum is restricted to gram positive organisms?
narrow spectrium agents
which cell is important in inactivating intracellular viruses?
natural killer cells
which cell surveys the body for stressed/abnormal cells and protects from cancer and viral infections?
natural killer cells
The genome of influenza virus consists of
negatively strand segmented RNA
which cell has a multilobed nucleus that acts as a phaogcyte defense against bacterial infection?
neutrophils also called PNM (polymorphonuclear monocytes) or scavenger cells
do you think that we will ever be able to eliminate all disease by use of vaccines and antibiotics?
no constant mutation and evolution getting vaccines to places getting people to get vaccines storing vaccines (refrigeration) vaccines can make a huge difference- eliminate in developed countries if high rate of vaccination herd immunity- few enough people not vaccinated, can't get continued transmission
Does gardasil (HPV vaccine) prevent all cervical cancers and genital warts?
no but most (31,200) strains most commonly associated with cervical cancers and genital warts
how does lactose and glucose control lac operon
no lactose: lac repressor binds = no transcription lactose: transcription occurs glucose present: prefers over lactose glucose and lactose: CAMP accumulates to activate CAMP receptor protein that helps RNA pol bind and increases lac operon activity
If Gene X codes for an F pilus and transposition occurs, then the bacterium containing the plasmid would
no longer be able to conjugate
can you get the flu from the flu shot
no the vaccine is made from either with flu viruses that have been inactivated and are not infectious or using only a single gene from a flu virus to produce immune response without infection
Have clinical studies shown that vaccines can cause autism?
no they have shown that there is no relationship
Boiling
non sterile, used on water, tableware, 100 degrees for 10 mins
virus
non-cellular particle (virion) that infects a host cell where it reproduces It typically subverts the cell's machinery and directs it to produce viral particles.
Based on gel electrophoresis, a nonfunctional protein is found to have a smaller molecular weight than its wild-type counterpart. A likely explanation for this observation is a
nonsense mutation in the DNA coding for the protein.
DNA in cells can encode for thousands of different proteins. Why do cells require mechanisms to regulate expression of the genes that code for these proteins?
not all proteins are needed at all times, or in equal amounts. Regulating their expression saves energy and time
When controlling microbes outside the body, ideal agents should be:
not harmful to humans or animals, inexpensive, easily cleaned up (easy to control), effective, work against a wide variety of organisms, fast acting, shelf stable
biological vectors
not only transmit pathogens but also serve as hosts for the multiplication of a pathogen during some stage of the pathogen's life cycle ex: tick carrying Lyme disease
Describe packaging of influenza
nucleoprotein coats RNA segments and has own RNA dependent RNA polymerase each RNA segment forms loop with nucleoprotein subunits that condense into a helix
oxygen tolerance
obligate aerobe obligate anaerobe microaerophile facultative anaerobe aerotolerant anaerobe capnophile
A(n) ________ organism require(s) oxygen for growth. A) anaerobic B) facultative anaerobic C) aerotolerant D) obligate aerobic E) aerotolerant and an anaerobic
obligate aerobic
A microbe that grows only at the bottom of a tube of thioglycollate medium is probably a(n) A) obligate aerobe. B) facultative anaerobe. C) aerotolerant anaerobe. D) microaerophile. E) obligate anaerobe.
obligate anaerobe.
Reducing medium is used to isolate ________ microbes. A) fastidious B) obligate aerobic C) autotrophic D) obligate anaerobic E) intracellular parasitic
obligate anaerobic
autotrophs
obtain carbon from CO2
Chemotrophs
obtain energy from chemicals
indirect contact transmission
occurs when pathogens are spread from one host to another by fomites- inanimate objects that are inadvertently use to transfer pathogens to new hosts Ex: E. coli on toothbrush, get sick
Cytosolic pathogens
often derived from viruses, degraded in cytosol, peptides bind to MHC class 1, presented to CD8 T cells, kills presenting cells Any cell can do this How cells get targeted for destruction by killer t cells when they are infected with a virus Initial activation that activates T cell might occur with dendritic cell Any cell can present antigen on MHC class 1 so that it can be targeted by CD8 t cell for cell death
In prokaryotic DNA replication, which of the following is FALSE?
on one parent strand, the polymerase synthesizes DNA in the 5' to 3' direction, while on the other it synthesizes DNA in the 3' to 5' direction
commensalism
one symbiont benefits without significantly affecting the other (absolute example difficult to prove, host may experience unobserved benefits) ex: hair follicle mites on skin ex: egrets and cattle
why have we not been able to eliminate most diseases using vaccination?
only eliminated one disease: not everybody gets vaccinated natural selection- mutations allow certain bacteria and viruses to escape detection lack of research for certain diseases even if everyone gets vaccinated, not every person will become immune, have to have really high rate of vaccination to eliminate if vaccine is 80-85% effective and everyone gets vaccinated you can eliminate hard in developing countries have to eradicate worldwide
Sporadic disease
only get randomly scattered cases, often times diseases that are not contagious person to person Ex: Botulism, tetanus
how does operon assist in gene regulation
operon: can expresses a set of genes (vice versa)
control of transcription for gene expression
operons regulated by protein repressors, activators, sigma factors, sRNA affects all genes of operon simultaneously
what is a fungal infection that causes life threatening systemic disease in immunocompromised patients? what is an example?
opportunistic/ overgrowth mycoses grows on internal organs through resp tract example: histoplasmosis: systemic candidiasis
Two pollo vaccines _____________- attenuated virus, 1 in 2,000,000 chance of getting polio, not used in US anymore ____________-whole killed virus, works well at preventing polio
oral polio inactivated polio vaccine (IPV) Main difference between them is that the Oral vaccine stopped virus replication in the gut so infected could not spread the disease. Whereas the inactivated Polio vaccine stopped the virus from entering the blood stream preventing any symptoms but the virus could still replicate in the gut and spread fecal/orally.
what happens during transplant rejection in organ grafts vs bone marrow transplant?
organ grafts: HOST T CELL kills bone marrow: MATURE T CELLS IN GRAFT kills
Heterotroph
organism that obtains energy from organic compounds (the foods it consumes)
chemoheterotroph
organism that use organic compounds for both energy and carbon;example- humans
some human diseases linked with causative DNA viruses
orthopoxvirus, parapoxvirus, simplexvirus, papillomavirus, reovirus, adeno associated dependoparvovirus A/B
The use of salt and sugar in preserving various types of foods is an application of which of the following concepts? A) nitrogen fixation B) osmotic pressure C) pH D) hydrostatic pressure E) quorum sensing
osmotic pressure
Vaccine Safety
overall very safe problems associated with immunization mild toxicity is most common- site reaction, fever can get high fever with live, MMR anaphylactic shock allergic reaction that may develop to a component of the vaccine Residual virulence attenuated viruses occasionally cause disease in healthy children or adults ex: roda, polio
The coenzyme NADH is generated by
oxidation reactions in glycolysis and the TCA (Krebs) Cycle
The terminal electron acceptor in aerobic respiration is ______.
oxygen
Microaerophiles are microbes that grow best at low A) carbon dioxide levels. B) pH values. C) hydrostatic pressure. D) oxygen levels. E) salt concentrations.
oxygen levels.
Droplet transmission
pathogens can be transmitted within droplet nuclei that travel less than a meter from the body during exhaling, coughing, and sneezing ex: some one sneezes on you with cold and you get cold
To isolate penicillin-resistant mutants, the scientist must inoculate the parent population on plates containing _____; this approach is _____ selection.
penicillin; direct
Central Metabolic Pathway
pentose phosphate pathway glycolysis fermentation transition step TCA Cycle respiration
lysogeny
persistence of a prophage by being replicated as host cell reproduces and doesn't destroy cell
A prophage is a
phage genome integrated into a host genome.
lag phase
phase in a growth curve in which the organisms are adjusting to their environment; A in the image
death phase
phase in a growth curve in which the organisms are dying more quickly then they are being replaced by new organisms; B in the image
log phase
phase in a growth curve in which the population is the most actively growing; C in the image
stationary phase
phase in a growth curve which new organisms are being produced at the same rate at which the older organisms are dying; D in the image
disinfectant that acts against cell membranes
phenol
Anabaena is a genus of filamentous cyanobacteria commonly found in aquatic environments, where it harvests energy from sunlight and fixes both carbon dioxide and nitrogen. Knowing this, how would you classify Anabaena?
photoautotroph
How would you classify the cyanobacteria from Greenlake in terms of their carbon and energy sources?
photoautotroph
You inoculate fern spores onto the surface of a growth medium in Petri dishes and wait for them to develop into gametophytes, a stage in the life cycle of a fern. The medium contains sources of nitrogen, phosphate, and a number of other macro- and micro-nutrients, but no carbon. After a few weeks, you see a contaminant growing on your plates. Assuming the organism is not digesting the agar itself, which of the following is most likely your contaminant?
photoautotrophic species of bacteria, archaea, or protists
A cell that uses an organic carbon source and obtains energy from light would be called a A) photoheterotroph. B) lithoautotroph. C) photoautotroph. D) chemoheterotroph. E) chemoautotroph.
photoheterotroph
A culture of E.coli is irradiated with UV light. The highest frequency of mutations would be obtained if after the irradiation, the cells were immediately
placed in the dark
what two cells do b cells produce upon activation?
plasma cells memory cells
which cells produce antibodies? where is this cell derived from?
plasma cells (found in lymphatic tissue-lymph nodes and spleen) derived from b cells
what are extrachromosomal DNA elements?
plasmid
which is a short lived fragment of large megakaryocytic that is responsible for blood clotting?
platelets
if a patient has a systemic infection with histoplasma infection what are some of the symptoms?
pneumonia ARDS cough
a single base pair mutation is called what? what are the three types?
point mutation 1. silent 2. missense 3. nonsense
obligate anaerobes
poisoned by oxygen
Enterovirus 68 (EV68) A respiratory infection, that can be severe, and is linked to _____________.
polio-like paralysis
virus that was widely used in living vaccines
poliovirus
common features
portal of entry: mouth portal of exit: feces human as the principle host, if not the only host transmitted from human to human, directly/indirectly low infectious inoculum of the etiological (E. bola - very low infectious inoculum)
Herpangina These lesions are similar to Hand Foot and Mouth, but limited to the _________ of the oral cavity. There is no involvement of the rest of the body This is also caused by ______________.
posterior Coxsakie A
what do you use for microscopic examination?
potassium hydroxide this helps dissolve cell wall so the structures can be seen
Pasteur set up the following experiment: he prepared a solution of sugar, ammonia, mineral salts, and trace elements, and added some yeast cells to it. He then measured the number of yeast cells as well as the sugar and alcohol levels over time. He noted that as the yeast cells multiplied, sugar levels decreased and alcohol levels increased, suggesting that the yeast cells were converting the sugar to alcohol. What do think would be an appropriate control for this experiment?
preparing a solution of sugar, ammonia, mineral salts, and trace elements, but not adding any yeast cells to the solution
What causes nosocomial infections?
presence of microorganisms in hospital environments, immunocompromised patients, transmission of pathogens between staff and patients and among patients
what functions like an autoclave?
pressure cooker
Bacteriostatic
prevents bacteria from growing
inhibition of integrase antiviral drug
prevents formation of provirus- integration of viral genome HIV infections
inhibition of membrane fusion antiviral drug
prevents viral genome from fusing and entering host cell HIV infections
The main purpose of cellular respiration is to
produce energy
Where is C reactive protein produced and what is its purpose?
produced in liver purpose: increases during inflammation, binds to bacteria to initiate phagocytosis, activates macrophages
why is second degree response more enhanced?
proliferation of b memory cells during the first degree response
what three things for required for MHC Class I presentation?
proteasomes ubiquitin TAP1 and TAP2: transporter associated proteins
Combination Vaccines
protect against several diseases at once MMR: measels, mumps, rubella Pentacel: DTaP+polio+HiB respond really well to multiple antigens at once
Why are pregnant women urged to get a Tdap vaccine during every pregnancy?
protects newborns from pertussis which is life threatining they don't get vaccine until 1 yr old
prions
proteins that infect animals.
Temperature
psychrophile mesophile thermoduric thermophile hyperthermophile
transition mutation
purine to purine or pyrimidine to pyrimidine
if a patient has a b cell deficiency, then he/she is more susceptible to what condition?
pyogenic (pus producing) bacterial infection
In the process of ________, microbes detect the presence and density of other microbes and modify their metabolic activity in response. A) quorum sensing B) antagonism C) mutualism D) symbiosis E) synergy
quorum sensing
spontaneous mutations
random change in the DNA due to errors in replication that occur without known cause
Substrate
reactant of an enzyme-catalyzed reaction
During phase variation there is a
rearrangement of an organism's DNA
factors that make influenza so virulent
reassortment that rapidly generates new strain that immune system fails to recognize mutation: leads to new phenotypes leading to drug resistance and host range
control on mRNA stability for gene expression
regulated by RNase activity where mRNA is degraded as fast as it is transcribed sRNA binds to RNA transcripts to help/hinder degradation
response regulator of 2 component signal transduction system
regulator turns genes on or off in response
second messengers
relays a signal to a cell's interior in response to a signal received by a signal receptor protein - amplifies message on inside
Sanitization
removal of pathogens to meet public health standards
Transcription is often controlled by DNA-binding proteins. A(n) _______ is a regulatory protein that blocks transcription, while a(n) ________ is a regulatory protein that facilitates transcription.
repressor; activator
obligate aerobes
require O2 for cellular respiration, also final e- acceptor of ETC
generalized recombination
requires that the two recombining molecules have a considerable stretch of homologous DNA sequences.
site specific recombination
requires very little sequence homology between there combining DNA molecules. But it does require a short sequence recognized by there combination enzyme.
riboswitches
resemble activator' repressor proteins in that they bind to cell metabolite to control gene expression Assume 2 stem loops that switch back and forth in response to target metabolite
cross resistance is
resistance to one antimicrobial agent because of its similarity to another antimicrobial agent
If you find that a particular plasmid has a R factor, the bacteria that has it will be
resistant to certain antibiotics
tuberculosis
respiratory infection caused by the the bacteria /Mycobacterium tuberculosis/; identified using acid fast staining
The most frequent portal of entry for pathogens is
respiratory tract
if a patient has a t cell deficiency, then he/she is more susceptible to what condition?
response to viral infection response to intracellular bacteria (Tb and Legionella) response to fungi/protozoa
flagellar running
rotate in a counterclockwise direction, allowing the bacterial cell to move forward
Topical application
route that works for topical problems- external infection, ex: athletes foot, ring worm, jock itch; treated with topical cream, some skin bacterial infections, has to be something on surface
which is a gram negative rod that is a member of the enteric bacteria class?
salmonella
what term best describes the disinfecting of cafeteria plates?
sanitization
what are organisms that get energy from living on decaying matter?
saprobes
the key to successful chemotherapy is
selective toxicity
what does Rifampicin B do?
selectively binds to bacterial RNA pol and inhibits transcription initation
which type has old and new strand replication?
semiconservative
proteins of the 2 component signal transduction system
sensor histidine kinase and response receptor
In a two-component signal transduction system, the __________ senses a change in the environment and the __________changes gene expression.
sensor, response regulator
retroviruses are divided into 2 major groups and describe each group
simple viruses: simple genomes causes tumors and leukemia lentiviruses: complex genomes that cause infections that progress slowly over many years
In transformation, genes from a donor chromosome are transferred as
single stranded DNA
The carotenoid pigments of some phototrophs interact with ________ to reduce its toxicity. A) singlet oxygen (1O2) B) hydroxyl radical (HO-) C) peroxide anion (O22-) D) superoxide radical (O2-) E) molecular oxygen (O2)
singlet oxygen (1O2)
what type of macrophage is found in the spleen?
sinusoidal lining cell
Temperature phages use
site specific recombination to incorporate their genome into the host genome for prophage replication until the host's growth is threatened.
Picornaviruses (this information is true about all picornaviruses except rhinovirus) _____, ______, ______ _______ virus +ssRNA , Naked, icosahedral Unlike other viruses that can be spread through the fecal oral route, can sometimes be spread through the _________ route. Resistant to: many common __________ 70% ETOH Various detergents Acidic pH
small, RNA, virus Lytic respiratory disinfectants
Acinetobacter baumannii is a common resident of _______.
soil and water
Infections caused by A. baumannii have most frequently been in
soldiers at military hospitals
Environmental conditions
some objects you can't use harsh chemicals or extreme heat on (humans, animals, fragile objects) For example, microbes on cell phones- no Dcon or autoclave, limitations pH of item to be treated- heat kills more quickly at acidic pH pH at which something is normally found impacts how well antimicrobials work limitations- cannot use heat to treat milk bc cannot make milk super acidic or will taste bad presence of organic matter (harder to kill things)- organisms in biofilms harder to kill temperature also affects efficacy when talking about chemicals warmer temp- most chemicals will kill bacteria much faster than they will at a cooler temp
lag phase
species, the chemical, and physical conditions of the medium (nutrients or no), any environmental factors affect the _____ _____
a direct fluorescent antibody test can be used to detect the presence of
specific antigens
The F pilus binds to
specific receptors on the cell wall of the recipient
describe the structure of the HIV virion
spikes of glycoprotein reverse transcriptase capsid RNA viral envelope matrix protein
Where are dendritic cells found?
spleen and lymph nodes purpose: antigen presenting cell
what is the difference between spontaneous mutations and induced mutations?
spontaneous: DNA replication errors induced: exposure to mutagens like chemical, non/ ionizing radiation, carcinogenic
waterborne transmission
spread of many gastrointestinal diseases, including giardiasis, amebic dysentary, and cholera water can act as vehicle and reservoir for infection Fecal-oral infection
contact transmission
spread of pathogens from one host to another direct, indirect, or respiratory droplets
Vehicle transmission
spread of pathogens via air, drinking water, and food, as well as bodily fluids being handled outside the body airborne, waterborne, food borne, bodily fluid
what catalase positive bacteria is known for the production of toxins such as hemolysin and leukocidins?
staphylococcus causes toxic mediated disease such as toxic shock syndrome impetigo scalded skin syndrome
In translation, the codon at which the process begins is called the _______ codon, while the codon at which the process ends is called the _______ codon.
start;stop
Rates of cell production and cell death are approximately equal during the ________ phase of growth. A) lag B) log C) death D) stationary E) intermediate
stationary
Ultrahigh-temperature sterilization
sterilization of dairy, 140 degrees for 1-3 sec
Autoclaving
sterilization, moist heat plus pressure, 121 C or 143 C well above boiling
which bacteria is cocci shaped and arranged in pairs and is gram positive and catalase negative?
streptococcus gram positive = purple
what other organism is commonly mistaken for listeria and also causes meningitis?
streptococcus pneumoniae
Epidemiology
study of where and when diseases occur and how they are transmitted within populations Incidence- # of new cases Prevalence- # of total cases For short lived cases might be similar For chronic infections- incidence is much smaller ex: HIV Prevalence of HIV 0.8% worldwide are positive for HIV 40% in southern parts of Africa
what is the term for when the effectiveness of the antibiotics together is greater than that of the drug alone
synergy has to have two different targets
in order to obtain immediate immunity against tetanus, a person should receive:
tetanus toxoid vaccine and immunoglobulin against tetanus toxin
F+ refers to a cell containing
the F plasmid
After the transfer of the F plasmid is complete
the F- cell becomes F+
To which part of a DNA molecule are nucleotides added?
the hydroxyl group on the 3' end of the molecule
HIV and other lentiviruses can be very useful vectors for gene therapy if
their virion production genes are used on helper plasmids to produce more virions with transgenes in cell culture.
Ted heats some food just to boiling, and stores some of it immediately in a container which he places in the refrigerator. A week later he takes the food out and finds it has spoiled. The microbes responsible are probably A) thermoduric. B) thermophiles. C) mesophiles. D) hyperthermophiles. E) psychrophiles.
thermoduric
features of priods
they have no nucleic acid component. They have an abnormal structure that alters the conformation of other normal proteins.
epitope
tiny part of antigen that T cell receptor, B cell receptor, or antibody actually binds to
Routes of Administration of antimicrobials
topical, oral, intramuscular, intravenous
therapeutic index=
toxic dose/therapeutic dose
regulatory RNA and mechanism: cis antisense RNA
transcribes from non template DNA that lays opposite from mRNA encoding strand and Can base pair cognate sense mRNA and control their expression
Which of the following statements concerning transcription and translation in eukaryotes is TRUE?
transcription occurs in the nucleus and translation occurs in the cytoplasm
what process occurs in which DNA is transferred from one bacterium to another via a virus? what does it require?
transduction bacteriophages
conjugation
transfer of DNA through direct contact using conjugation pilus
horizontal gene transfer
transfer of genes between cells of the same generation
sensor kinase of 2 component signal transduction system
transfers P from ATP to activate protein`
MCPs (methyl-accepting chemotaxis proteins)
transmembrane chemoreceptors that modulate the autokinase activity of CheA in response to changes in ligand occupancy and methylation state.
which enzyme is responsible for site specific recombination?
transposase-----an example of a recombinase
what are movable genetic elements that can cause spontaneous mutations?
transposons
how does gram positive transform
triggered by quorom sensing need phase dependent assembly of transformasome across cell membrane and makes cell competent
how can sigma factors be regulated: sigma S
triggered by stress that slows growth accumulation during exponential and stationary phase = proteolysis
what does Puromycin do
triggers peptidyltransferase prematurely
why are human viruses difficult to study
tropism: has to work specifically with that virus most tissue we are working with is not humans and can't be relevant to human bc tropism
T/F: The energy captured in the phosphorylation of ADP to ATP comes from the proton motive force created in respiration.
true
T/F: Transposons can potentially inactivate bacterial genes by "jumping" into them.
true
T/F: Whenever a molecule is oxidized, another molecule must be reduced.
true
Farmer's lung is a hypersensitivity pneumonitis resulting from
type iii hypersensitivity to mold spores
what is the life cycle of histoplasma capsulate? what type of fungal infection is it?
type: endemic mycoses 1. bird spreads conidia through soil with bird feces 2. inhalation of conidia 3. conidia is converted to yeast 4. yeast enters tissue macrophages 5. yeast leaves macrophage and spreads throughout the body
A bacterial cell that lacked the Rho protein would be
unable to terminate transcription of some genes
What are some common but misguided reasons why parents don't vaccinate their children appropriately?
unsafe, scared of side effects, breastfeeding gives immunity, wait until school, overload immune system, too many doses, natural immunity, think disease is gone, don't understand severity of disease, too early-want to delay
adenovirus
used to transiently infect, and are engineered not to integrate into the host genome. They also tend to trigger an immune response in the subject. eventually lost and treatment has to be repeated
Why is the OPV (oral polio virus) vaccine no longer used in the US?
virus was becoming reactivated as it went through babies' GI tracts, so live virus was showing up in the feces (parents and daycare workers catching polio from changing diapers)
horizontal transmission
viruses are transmitted among individuals of the same generation
importance of plaques
viruses can't be isolated into single colonies like bacteria Offer convenient way to isolate recombinant DNA contained in bacteriophage vector
icosahedral viruses
viruses with a polyhedral capsid with 20 triangular facets spike proteins
Engineered herpes viruses are being used to treat cancer because the virus
was engineered as an oncovirus, only infecting tumor cells.
How does mucous protect the body?
wash away microbes ex: lungs
The electrons excited by photons of light are replaced by electrons from ______ in photosystem II, and by electrons from ______ in photosystem I.
water; photosystem
conjugate vaccines
way of tricking immune system allow a strong immune response against a non-protein (polysaccharide) antigen trick it into producing IgG when it would usually just produce IGM polysaccharide is conjugated to a protein antigen- ex- tetanus toxoid- everyone already immune to so have a strong response to that B cells recognize polysaccharide, engulf it, display the proteins from the proteins antigens helper T cells that recognize tetanus toxoid activate B cell to do isotope switching so it can produce all different types of antibodies trick immune system into having better immune response against non-protein antigen than it would on its own example: HiB influenza vaccine
warm, acidic
what disinfectant works best. Cold or warm. acidic or basic
Cell wall and membrane, proteins and nucleic acids
what is the most effective physical or chemical methods of control are capable of killing or removing what microbial structure
refrigeration, freezing, osmotic pressure, desiccation
what physical control methods inhibit metabolism/ proteins and enzymes
incineration, hot air
what physical control methods oxidize
Autoclaving Boiling Pasteurization UHT hot air
what physical controls denature proteins and membranes
Artificially acquired active immunity
what you get from vaccination, exposed to antigens but not to full fledge disease, mount an immune response against those, as a result form own memory cells
double in size
when do cells reproduce?
when does listeria grow in abnormally large amounts?
when exposed to a high concentration of salt
Enviornment
where do cellular microbes get their nutrients
inner membrane of mitochondria
where is the ETC in eukaryotes
cellular membrane
where is the ETC in prokaryotes
what is an example of a facultative anaerobe fungi?
yeast ( candida) that lives in oropharynx, gut and vagina
zone of inhibition
zone of clearing seen around an antibiotic disk where bacteria was prevented/inhibited from growing; shows bacteria are sensitive to an antibiotic
THE HUMAN DIGESTIVE SYSTEM
◦ A "tunnel" thru the body ‣ If the body finds something offensive, it would try to expel it from one end to another ◦ Although physically located inside the body, it is isolated from internal human body. ◦ Selective in exchange between digestive track and body ◦ Absorb nutrients ‣ Water ‣ Electrolytes ‣ Digested food ‣ Etc. ◦ Keep out unwanted intestinal components ‣ Excessive water and electrolytes ‣ Large molecules ‣ Microorganisms ‣ Etc.
post translational modification: proper "folding"
"folding" of the polypeptide and association of multiplepolypeptide subunits, often facilitated by chaperone proteins, into a distinct three-dimensional structure
Tansposons can cause mutations by
"jumping" into a gene and disrupting its function
hydroxyl radical
(OH) results from ionizing radiation and from incomplete reduction of Hydrogen Peroxide
Why does antibiotic result to more diarrheal diseases?
- Because it wipes out our microflora which helps fight GI pathogens
WHAT ARE THE SYMPTOMS WHEN PATHOGENS ARE CONFINED IN GI TRACT?
- Diarrhea - Vomiting - Nausea - Fever
What are clinical manifestations of H.pylori?
- Mostly asymptomatic - But can lead to stomach ulcer, duodenum ulcer, gastritis - long term ulcer can lead to stomach cancer
Why is Microbiome important?
- Regulate intestinal environment - Control proliferation of pathogens - Affect metabolism - Regulate development of immune system - Protect against damages in intestines - Some pathogens have benefits: Such as H.pylori which lowers incidence of asthma in children
Which of the following DNA repair mechanisms is error prone?
SOS repair
types of vaccines
attenuated (live) killed (inactivated) subunit toxoid conjugate combination
If a protein-encoding gene contains introns and exons, it is likely that
it is a eukaryotic gene
oxidizing agents, aldehydes, gaseous agents
which chemical agents can sterilize
diffusion and dilution tests that expose pathogens to antimicrobials are designed to determine
which drug is most effective against a particular pathogen, the amount of a drug to use against a particular pathogen
error proof repair pathways
which prevent mutations
error prone repair pathways
which risk introducing mutations
Innactivated Vaccines
whole agent or subunit both types are safer than live vaccines no chance of getting disease, inactivated or dead killed bacteria or inactivated virus when microbes are killed must not alter the antigens beneficial for extracellular bacteria recognized as exogenous antigens stimulate a TH2 response/humoral immunity stimulate antibody repsonse good for bacterial infections and for viral infections in neutralizing before infection of cell
Helper T cells
wider variety CD4 Activate B cells (protein antigens) helped to secrete different types of antibodies Activate macrophages Sometimes activate cytotoxic T cells
PARASITIC PATHOGENS COMMON FEATURES
• Infections by parasites inlcuding protozoans and parasitic helminths • Lifecycle***** ◦ Taking different forms to complete life cycle (eggs or cysts, trophozoites, larva, adult forms, etc.) ◦ Some need additional hosts before transmitting to human • Incubation period ◦ 1-3 weeks • Can be treated • No permanent damage in most cases
ATP synthase
All of the following are exoenzymes except
Patented
Transgenic organisms are
Phototrophs
obtain energy from light
A recombinant organism is
one that contains genes from another organism
Enzymes are usually _________?
proteins
