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final exam Flashcards

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1
Q

chLUCA

A

the Last Universal Common Ancestor
The evolution of protobionts led to an organism(s) that is the precursor to all current life on Earth
We know it stored genetic information in DNA
Roughly 350 genes common among all life forms
We know it used proteins for catalysts
We know it used ATP as a major energy source

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2
Q

“Uncontestable” Microfossils

A

The oldest fossil evidence of life is from 3.8 byo stromatolites found in Western Australia
The first cells were Prokaryotes - a membrane surrounding cytoplasm containing loose DNA with simple metabolism

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3
Q

The Great Oxygenation Event

A

Resulted from the evolution of oxygenic photosynthesis by cyanobacteria

Oxygen first saturated the oceans and then accumulated in the atmosphere
O2 levels went from <1% to roughly 21%

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4
Q

It’s the End of the World(As We Know It)

A

This had a devastating effect on life on Earth!!
The “corrosive” O2 doomed countless anaerobic organisms
Only those organisms that had enzymes to “handle” oxygen could survive and reproduce
As oxygen levels increased slowly over time, the organisms that could remove O2 were selected for
Today we can classify species (mostly Prokaryotes) based on their oxygen requirements
Aerobic (require oxygen), facultative (can survive in presence of oxygen, but don’t require it), Anerobic (die when interacted with oxygen)

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5
Q

It’s the Beginning of the World(As We Know It)

A

The generation and persistence of oxygen allowed for an unprecedented increase in biological diversity:
The development of aerobic respiration
What better way to get rid of toxic oxygen than to reduce it to water? C6H12O6 + O2 –> CO2 + H2O + ATP
The development of an ozone layer
To protect the planet from mutagenic cosmic rays
Life could creep out of the primordial soup and colonize land…

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6
Q

Life is Predominantly Prokaryotic

A

99% of life on Earth are unicellular Prokaryotes
Prokaryote: Before the kernel (nucleus)
No membrane-bound organelles
nuclei, mitochondria, chloroplasts, ER
Divided into two groups
Bacteria and Archaea
Have adapted to every environment
Aerobic, anaerobic, acid-tolerant, salt-tolerant, radiation-tolerant

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7
Q

Eukaryotes Emerge

A

~ 1.8 bya, as Prokaryotes were optimizing photosynthesis and respiration, Eukaryotes appear in the fossil record
This occurred by the processes of Endosymbiotic Theory
Endo: Within. Sym: Together. Biotic: Life
One form of life living within another
Generated a bacteria/archaea hybrid

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8
Q

Endosymbiotic Theory

A

A small bacterium began living inside a larger archaea
Symbiosis refers to a close association between two organisms, Endo means within
The bacterium was efficient at aerobic respiration
The archaea was efficient at obtaining nutrients
Over time, the association became permanent
Neither can live without the other
The bacteria/archaea hybrid became a eukaryote
The bacterium is now an organelle = mitochondria
Also occurred with a photosynthetic bacterium = chloroplasts

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9
Q

Fireball Earth

A

With all the collisions, Earth was molten
As the collisions decreased, Earth cooled, and a crust formed
Atmosphere mainly composed of Hydrogen
Oceans formed as water cooled
Volcanoes erupted through crust dispersing simple, inorganic gases into the atmosphere

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10
Q

Primary Abiogenesis

A

Abiogenesis: Life out of no life
Simple inorganic molecules combined to become organic molecules of increasing complexity. Organisms are made of carbon
As these molecules became more stable and persisted longer in the environment, they initiated increasingly complex associations
Eventually, one gained the ability to self-replicate
Eventually, they became surrounded in a membrane
Led to the first cellular organisms
Spontaneous generation did occur, at the start when the Earth was very different

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11
Q

Anaerobic

A

no oxygen

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12
Q

Conditions of Early Earth

A

Anaerobic (no oxygen)
Oceanic
Filled with simple inorganic molecules
Hydrogen, methane, water , carbon dioxide, nitrogen, hydrogen sulfide, ammonia
High temperatures
Average global temperature of roughly 90 degrees
These conditions are almost perfect for spontaneous generation of life. The only other consideration is a source of….

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13
Q

Panspermia

A

Could life have evolved in outer space?
Murchison Meteor (7 byo) and found that it contained amino acids and nucleic acids

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14
Q

The Primordial Soup

A

The formation and persistence of simple organic molecules occurred in the Earth’s early oceans = the “primordial soup”

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15
Q

“primitive pizza”

A

The formation and persistence of simple organic molecules occurred in the Earth’s early oceans = the “primordial soup”
These molecules splashed onto volcanic clay “beaches”, which allowed polymerization into the four common biological macromolecules
Producing a “primitive pizza”

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16
Q

Polymerization:

A

Poly (many) mer (bodies). The joining of small building blocks into large molecules

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17
Q

Carbon dioxide

A

“captured” by photosynthesis, glucose is used in metabolism. Goals of metabolism: Energy and structure creation

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18
Q

Animals

A

require 25 elements

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19
Q

plants

A

require 17 elements

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20
Q

Cellular structure and metabolism

A

is based on carbon-containing (organic) molecules
50% of body mass is carbon (excluding water)
Other elements play important roles as well

Oxygen, hydrogen, nitrogen, phosphorus and calcium

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21
Q

Carbohydrates

A

(Carbon water) – (CH2O)n
Simple sugar - monomer + dimers
Complex sugar - polymers

Monosaccharides–3-7 carbons(Simple sugars)
Glucose, fructose, sucrose (disaccharide), etc.
Form of carbohydrate fed into metabolic pathways

Polysaccharides – 100-1000 monosaccharides
Glycogen, starch, cellulose
Form of carbohydrate used for long-time storage + building cells

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22
Q

Nucleic Acids

A

(C10H14N5O7P)n – ish!
Monomers – ATP, GTP, etc.
Complex polymers – RNA + DNA

DNA
Polymers of deoxyribonucleic acid nucleotides (monomer) that “fold” into a double helix
Used to store genetic information
RNA
Polymers of ribonucleic acid nucleotides that “fold” into complex three-dimensional shapes
Used to turn genetic information into proteins
Used as energy molecules (ATP, GTP)

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23
Q

DNA

A

Polymers of deoxyribonucleic acid nucleotides (monomer) that “fold” into a double helix
Used to store genetic information

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24
Q

RNA

A

Polymers of ribonucleic acid nucleotides that “fold” into complex three-dimensional shapes
Used to turn genetic information into proteins
Used as energy molecules (ATP, GTP)
RNA has an extra oxygen over DNA

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25
Q

Nucleoside

A

Monomer

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26
Q

Nucleotide

A

Polymerized

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27
Q

Lipids

A

(C39H75O10P)n – ish!
triglycerides + phospholipids

Water insoluble molecules composed mostly of carbon and hydrogen atoms (hydrocarbons)
The two major biological lipids are triglycerides + phospholipids

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28
Q

Saturated fats

A

do NOT have fatty acids that contain double bonds
completely saturated with hydrogen. CH3 - CH2 - CH3

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29
Q

Unsaturated fats

A

have fatty acids with one or more double bonds CH2 = CH - CH3

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30
Q

fatty acids

A

Fatty acid molecules can vary in the:
Number of carbon atoms in the hydrocarbon chain
Presence of double bonds between carbon atoms

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31
Q

Triglycerides

A

Fats mainly serve as energy-rich storage molecules
Consist of 3 fatty acid (hydrocarbon) chains bound to a glycerol “anchor”
The C-C and C-H bonds store lots of energy, that can be released when needed

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32
Q

Phospholipids

A

Glycerol
2 fatty acid “tails”
1 phosphate “head”
Attached to an organic molecule

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33
Q

Phospholipid Bilayers

A

In aqueous solutions, phospholipids form bilayers
Man-made bilayer vesicles are called liposomes

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34
Q

Biological Membranes

A

Compartmentalize the cell
The plasma (cell) membrane separates “out” from “in”
Internal membranes create additional cellular regions

Membranes are selectively permeable membranes, meaning not everything can pass through

Membranes are important for cell-cell communication. Site of biological reaction

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35
Q

The Lipid Bilayer is Fluid

A

Most phospholipid molecules are independent
Not bound to anything
Each is free to move along the plane of the membrane
Not all membranes have the same degree of fluidity…
Type of phospholipid affects the fluidity

Mixed with the phospholipids are proteins and sugars

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36
Q

The Lipid Bilayer is a Barrier

A

Large and/or charged molecules have a hard time squeezing between the phospholipids
EX. Glucose, sucrose, Cl-
Small and/or uncharged molecules can cross the membrane
EX. Water, glycerol
Fluid mosaic model

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37
Q

Diffusion and Osmosis

A

The tendency of dissolved molecules to evenly distribute themselves in a solution
Molecules move from areas of high concentration to areas of low concentration

Diffusion works across membranes, IF the molecule can cross the membrane
If not, water will move to dilute the concentrated side

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38
Q

Transport of Molecules

A

Most biologically important molecules are large and/or charged
Cannot diffuse across the membrane without help…
Cells have transport proteins, shaped like tunnels, that allow these molecules to cross the membrane

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39
Q

Proteins

A

NH3CHRCOOH)n
Short polymers – used as a food source
Complex polymers – polypeptides

Polymers of amino acids that “fold” into complex three-dimensional shapes
Oligopeptides (4-10 amino acids)
Used for Food
Used in cell-to-cell communication
Polypeptides (100s of amino acids, sometimes 1000’s)
Multiple uses determined by the overall 3D shape of the molecule

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40
Q

Amino Acids

A

Central (a) carbon
Amino group
Carboxyl group
R group
This is the part of the molecule that varies

There are “20” unique amino acids

Amino acids are linked together into peptides

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41
Q

Common Cellular Features

A

Cell membranes
Phospholipid bilayers that compartmentalize stuff
Cytosol
the fluid that fills a cell
The central dogma
DNA –> RNA –> Protein

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42
Q

Nucleus

A

Separates genetic information from rest of cell

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43
Q

Mitochondria/Chloroplasts

A

organic molecules synthesis
energy generation (ATP)

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44
Q

Endomembrane system

A

Lipid/protein synthesis – Endoplasmic Reticulum
Trafficking and excretion - Golgi Apparatus
Digestion and detoxification - Lysosomes
Storage - Vacuoles

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45
Q

Cytoskeleton

A

Internal and external structural support

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46
Q

Cell wall

A

External cell structural support
Plants and algae use cellulose, pectin, chitin

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47
Q

Centrosome

A

cell replication

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48
Q

Flagella/cilia

A

cell movment

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49
Q

Nucleoid

A

Area in the cytosol where genetic info is stored

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50
Q

Bacterial Cell Walls: Peptidoglycan

A

The carbohydrates NAG and NAM are bound to one another in an alternating sequence
Form long glycan (sugar) chains
NAM has a protein side chain that links adjacent glycan chains together
Forms a cellular lattice that surrounds the cell

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51
Q

Bacterial Cell Walls: Gram Reaction

A

Bacteria can be grouped into two main classes based on the thickness of their cell walls
Gram-positive bacteria have thick cell walls
Stain purple in a Gram reaction
Gram-negative bacteria have thin cell walls
Stain red in a Gram reaction

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52
Q

Lysozyme

A

Produced by multiple animal species including Homo sapiens…
Found in secretions like tears and saliva
Breaks the bonds between NAG and NAM in peptidoglycan
Without a cell wall, the cell lose structural support and will die

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53
Q

Penicillin

A

Produced by the soil fungus Penicillium chrysogenum
Binds to the enzyme that forms the protein cross-link between glycan chains

Without the cross link, the cells will die

Penicillin does not harm us because we do not have peptidoglycan

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54
Q

The Outer Membrane

A

Only found in Gram-negative bacteria
Similar structure to other biological membranes
Permeable compared to the plasma membrane
Lipopolysaccharides (LPS) make up ~40% of the external leaflet

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55
Q

Lipopolysaccharide (LPS)

A

O-specific side chain (O antigen)
Various polysaccharides
Helps stick to surfaces
Species-specific
Core Polysaccharide
More polysaccharides
Genus-specific
Lipid A (glycolipid)
A toxin that causes inflammation when found in the blood

56
Q

Heredity/Inheritance

A

The transmission of traits from one generation to the next (parental generation to offspring generation)

57
Q

A trait

A

is any characteristic of an individual that is heritable

58
Q

Gregor Mendel

A

Studied inheritance in garden peas (1865)
Tracked changes in flower colour (and other characteristics) in thousands of pea plants
Worked out a mechanism showing how traits from one generation could be passed down to the next

59
Q

genome

A

All the genes of a species make up its genome

60
Q

genotype

A

All the alleles of an individual make up its genotype

61
Q

phenotype

A

the physical, observable trait

62
Q

allele

A

one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

63
Q

the principle of segregation

A

The two alleles of every gene separate in each parent and a new combination comes together in offspring
Each parent contributes one allele for each gene

64
Q

principle of independent assortment

A

Every gene separates independently from one another
Different genes (i.e., flower colour and seed shape) are not linked

65
Q

Gametes

A

a reproductive cell of an animal or plant.
have 1 copy of each chromosome

66
Q

Zygotes

A

zygote is a eukaryotic cell formed by a fertilization event between two gametes
are a random combination of 2 gametes

67
Q

karyotype

A

the number and visual appearance of the chromosomes in the cell nuclei of an organism or species.

68
Q

Morgan

A

studied inheritance patterns in fruit flies

He crossed fruit flies with various eye colours to determine if he could identify patterns that followed the predictions of Mendel’s model
They didn’t.
All his models assumed that the eye colour gene would occur twice – once for each copy of a chromosome

Morgan realized that if the gene for eye colour was on the X chromosome (but not the Y), the inheritance pattern supported Mendel’s ideas

69
Q

Nettie Stevens

A

discovered that the sex chromosomes determine gender (females are XX and males are XY)
X is a normal looking chromosome, but Y is kind of piddling and simple…

70
Q

Chromosomes

A

are composed of both proteins and DNA
Proteins:Composed of 20 amino acids
Millions of possible 3D structures
Complex enough to store heritable information
DNA:
Composed of 4 nucleic acids (nitrogenous bases)
Simple and limited 3D structures
Thought to play a structural role

Today we know that DNA is storing genetic info and proteins are there for structural support.

71
Q

Streptococcus pneumoniae

A

Bacterium that causes pneumonia, ear infections, and meningitis
A significant cause of child mortality before the development of antibiotics and vaccines

72
Q

Griffith et al.

A

In 1928, Griffith published a paper of observations he made while trying to develop a vaccine

73
Q

AVERY et al.

A

Kill S cells, lyse the cells, remove the lipids and sugars (RNA, DNA and protein is left)

Add DNAase
Breaks down DNA
Add living R cells to each tube
Look for S cells (transformation)

74
Q

discovering DNA

A

Franklin produced an X-ray crystallograph of DNA
Wilkins (Franklin’s supervisor) showed the images to James Watson
Watson and Crick pieced together the structure based on Franklin’s data and Chargaff’s rules

75
Q

double helix

A

DNA molecules exist as two “strands” coiled into a

76
Q

Chromatin

A

is the normal form of DNA, this is how it exists in our cells most of the time
The “normal” state of our genetic material
During DNA replication and transcription, it “opens”
During cell division, chromatin condenses further to form a chromosome

77
Q

Transcription

A

(DNA to RNA)
A particular DNA sequence (a gene) will specify an RNA sequence

78
Q

Translation

A

(RNA to protein)
A specific RNA sequence will specify an amino acid sequence

79
Q

codon

A

Every 3 nucleotides form a codon
Each codon codes for a specific amino acid.

80
Q

Messenger RNA

A

RNA, transcribed from DNA, that acts as a template for translation of specific proteins

81
Q

Ribosomal RNA (rRNA)

A

RNA that folds into a ribosome and catalyzes translation

82
Q

Transfer RNA (tRNA)

A

RNA that link specific amino acids and delivers them to ribosomes during translation

83
Q

Mutation

A

A permanent change in a DNA sequence that changes an organism’s genotype
Most mutations only affect one organism
Mutations in gametes are passed on to offspring

A mutant is an organism that has undergone one or more mutations

Mutations can occur spontaneously as a mistake during DNA replication
Mutations can be induced by X-rays, microwaves, UV radiation
Mutations can be induced by chemical mutagens

84
Q

point mutation

A

single location in DNA sequance

85
Q

base pair mutation

A

change to a single nucleotide within a gene

86
Q

substitution mutation

A

one nucleotide is replaced by another

87
Q

insertion mutation

A

one nucleotide is added

88
Q

deletion

A

a nucleotide is removed

89
Q

silent mutation

A

a base pair mutation that results in the same amino acid

silant mutations have no effect

90
Q

Missense Mutations

A

is a point mutation in which a single nucleotide change results in a codon that codes for a different amino acid

can change phenotype

91
Q

Nonsense Mutations

A

a point mutation in a sequence of DNA that results in a premature stop codon, or a nonsense codon in the transcribed mRNA, and in leading to a truncated, incomplete, and usually nonfunctional protein product

92
Q

Frameshift Mutations

A

Occur when a deletion or an insertion alters the
reading frame

93
Q

Viruse

A

are non-cellular, infectious particles

There are multiple viruses of every eukaryotic and prokaryotic organism

Require living host cells for reproduction (metabolism)
Can’t make ATP, ribosomes, amino acids, …
Symbiosis has negative effect on host
Broad (West Nile, encephalitis), or narrow (measles) host range

94
Q

Viral Structure

A

All viruses consist of a nucleic acid genome covered by a protein coat called a capsid

Some viral capsids are surrounded by a phospholipid bilayer
envloped has membrain stolen from host

Viruses have glycoprotein spikes

95
Q

Extracellular

A

Extracellular
the viral genome surrounded by a protective coat of protein; the resulting nucleocapsid may be surrounded by an outer lipid envelope in which viral proteins are embedded. Viral proteins confer specificity as to the range and type of host cell that may be infected.

96
Q

Intracellular

A

Exist as replicating nucleic acids
non-infectious

97
Q

virulent

A

of a disease or poison) extremely severe or harmful in its effects.

98
Q

lytic cycle

A

distroys host cells

99
Q

Lysogenic cycle

A

does not destroy cells

100
Q

Lytic Infection

A

Viral capsid proteins or glycoprotein spikes attach to receptors on host cell membranes

Capsid proteins dissociate from genome
Viral genome uses host energy, enzymes and building blocks to replicate
Progeny virus particles assemble
Progeny virus leave host through
induces membrain fusion

101
Q

Lysogenic Infection

A

Attachment/Adsorption like
Viral DNA becomes integrated into host genome
Viral DNA is called a provierus
The host is called a lysogen
As the lysogen divides, the provirus is replicated too
Produces a population of host cells infected with provirus
The virus is latent (dominant)
The provirus can exit the host genome and the viral DNA then enters the lytic cycle

102
Q

The Germ Theory of Disease

A

Soon after they were discovered, scientists began
to suspect that microbes were responsible for
disease
* Replacing the miasma theory

103
Q

Robert Koch

A

First to link specific bacteria to specific diseases
* Studied anthrax and tuberculosis (consumption)
* Formulated Koch’s Postulates for determining the
microbial cause of infection

104
Q

Koch’s Postulates (1876)

A

1.a specific organism must be associated with all cases
2. a specific organism should be isolated and grown within a lab
3. after it should spark desease within healthy individuals
4. the desease should be re-isolated from deseased individual

105
Q

Australian scientists Marshall & Warren (1980s)

A

Studied gastritis, ulcers
* Believed to be due to over production of stumic acid
* Treated with “bland” diets and antacids daily for life
*Discovered/isolated H. pylori from tissue biopsies
* Couldn’t find an appropriate animal model
* No one believed microbes could
* 10 years later, frustration set in

106
Q

Helicobacter pylori

A

Found in 50% of the human population
* Leading cause of gastric inflammation (gastritis) and
ulcers
* Causes gastric cancer in 1% of patients
* Uses helical shape and flagella to penetrate the
thick mucous lining the stomach
* H. pylori uses urease to generate ammonia
* Produces toxins to damage epithelial cells in order
to gain nutrients
* Successfully resolved with specially formulated
antibiotics

107
Q

latent desease

A

hidden in a reservoir or host

108
Q

isolated desease

A

restricted to one or a few individuals

109
Q

endemic desease

A

common in a population

110
Q

epidemic desease

A

rapidly spreads through a population

111
Q

pandemic

A

rapidly spreads across all populations

112
Q

virulence

A

elative ability of a pathogen
to cause disease

113
Q

pathogen

A

a microorganism that causes
disease

114
Q

virulance factors

A

– molecules produced by, or
strategies used by, a pathogen to cause disease
* Attach to host cells – fimbriae/pili, capsules
* Evasion of host immune system – capsules, enzymes
* Invasion and spread – flagella, extracellular enzymes
* Acquisition of nutrients – toxins and enzymes

115
Q

Infection
* Portal of entry

A

Skin (wounds or bites)
* Gut (need to survive acidic stomach)
* Mucous membranes (nose, mouth, eyes, etc.)
* Mucous is composed of mucin (glycoproteins and
polysaccharides)
* Most “normal” microbes cannot penetrate
* Pathogens have flagella and enzymes that degrade mucin

116
Q

hyloriadias

A

destroys hyaluronic acid

117
Q

collegenace

A

destroys collagen

118
Q

Endotoxin

A

Permanent component of outer cell membrane in Gram-
negative bacteria
* Properties
* Heat resistant – won’t degrade at body temperature
* Poor Immunogen – does not stimulate anntibodys
* Symptoms
* Fever, diarrhea, vomiting, low blood pressure, general
inflammation(body trying to get it out)
* Prognosis
* Toxicity is low – immune system clears it out
* Unless things get out of hand – septicemia – leads to septic
shock – multi-organ system failure - death

119
Q

Toxins

A
  • From the Greek word for “bow”
  • Relating to the use of poison arrows
  • Properties
  • Heat labile – destroyed at high temp
  • Immunogenic – stimulate antibodys
  • Symptoms
  • Various – but all involve destroying cells
  • Prognosis
  • Toxicity is high – small concentrations can be very damaging
  • Numerous types
  • Exotoxins, enterotoxins, neurotoxins, hepatotoxins,
    cytotoxins, …
120
Q

Immunogenic

A

stimulation of antibody responce

121
Q

Cytotoxins

A

cell killers
cell poison
I.e., Diphtheria
* Caused by Corynebacterium diphtheriae
* Inhibits
* Results in organ failure
* As well as suffocation
* Virtually eliminated in “developed” countries with
access to the
* Can be treated with antibiotics

122
Q

Neurotoxins

A

reacts with nerve system

123
Q

Botulism

A

Food Botulism
* We eat C. botulinum all the time!!
* They can’t compete with our normal gut bacteria
* BUT if the bacteria produce toxin in food before we eat…
* Exposure via unpasteurized milk/honey/juice or improper canning
* Infant Botulism
* Babies don’t have gut bacteria!
* Wound Botulism
* Spores enter wounds, wounds “heal”, organisms grow and produce toxin
* Toxin is absorbed in small intestine, enters bloodstream, and moves
to motor neurons
* Treatment via antibiotics and antitoxin, but there is no way to heal
an affected neuron – must be replaced

124
Q

Tetanus

A

Normally enters body through wounds
* C. tetani is everywhere!!
* Loves to grow in healing tissues
* Toxin enters bloodstream and moves to motor neurons
* Treatment via antibiotics and antitoxin, but there is no
way to heal an affected neuron – must be replaced
* Virtually eliminated in “developed” countries that have
access to the

125
Q

Enterotoxin

A

Affects the intestens
* I.e., Cholera
* Caused by Vibrio cholerae
* Exposure via food/water contaminated with feces
* Blocks Na+ from entering cells and pumps Cl- out of cells
* Water leaves blood and intestinal cells to
*
* Results in severe diarrhea leading to dehydration and electrolyte
loss
* Treatment via rehydration therapy and antibiotics
* Virtually eliminated in “developed” countries with access
to

126
Q

Disinfectants are used on

A

Detergents - molecules that disrupt membranes

127
Q

Antiseptics are used on

A

Alcohols disrupt lipid membranes and denature
proteins

128
Q

selective toxicity

A

inhibit or kill only the
pathogen without damaging the host

129
Q

Narrow-spectrum

A

affect only specific microbes or
groups of microbes

130
Q

Broad-spectrum

A

affect a wide range of
microorganisms

131
Q

Sir Alexander Fleming

A

discovered penicillin in 1929
* The penicillins are b-lactams that inhibit the
formation of peptidoglycan
– Prevents new cell wall synthesis
– More effective against Gram+ than Gram–
– Most widely used antibiotics in the world

132
Q

Polymyxins

A

insert themselves into membranes,
forming a pore that causes leakage of
metabolites

133
Q

rifamycins

A

ifamycins inhibit the DNA-dependent RNA polymerase of mycobacteria, resulting in decreased RNA synthesis. These agents are generally bactericidal at treatment doses, but they may be bacteriostatic at lower doses.

134
Q

tetracyclines

A

inhibit protein synthesis by preventing the attachment of aminoacyl-tRNA to the ribosomal acceptor (A) site.

135
Q

quinolones inhibit

A

rapidly inhibit DNA synthesis by promoting cleavage of bacterial DNA in the DNA-enzyme complexes of DNA gyrase and type IV topoisomerase, resulting in rapid bacterial death

bio 205 (1 decks)

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