Exam 1 Flashcards
(145 cards)
0
Q
Structures not found in all bacteria
A
Inclusions, capsules, cell walls, fimbriae, plasmids and flagella. Alsmost all prokaryotes have cell walls
1
Q
Structures that are found in all bacteria
A
Cytoplasm, ribosomes, plasma membrane, nucleotide containing DNA
2
Q
Fimbriae location
A
Polar or evenly distributed
3
Q
Characteristics of prokaryotic cytoplasm
A
DNA, inclusions and ribosomes
4
Q
T/F?
Prokaryotic plasmids may carry genes that provide antibiotic resistance to the cell
A
TRUU
5
Q
What are endoflagella?
A
Bundles of fibrils that arise At the ends of a cell, beneath an outer sheath and which spiral around the cell, aiding movement
6
Q
Tumbles occur when
A
The flagella rotate clockwise
7
Q
Monotrichous
A
Have only one flagellum
8
Q
Petrichous bacteria make a run when
A
The flagella turn clockwise and become bundled
9
Q
Bacterial cells with flagella located at one end are
A
Lophotrichous and monotricous
10
Q
TF? Flagella can rotate 360ô°
A
True
11
Q
Taxis
A
Movement toward or away from a stimulus
12
Q
Positive phototaxis
A
Movement toward light
13
Q
As bacterium approach a food source you would expect
A
Runs should become more frequent
14
Q
Why are receptors on the cell surface necessary for bacterial movement?
A
Receptors sense stimulus and send a signal to the flagella
15
Q
What structural part of a bacterial flagellum is composed of flagellin
A
The filament
16
Q
How are gram positive and gram negative flagella different?
A
A gram positive flagellum has only two rings in its basal body. Gram negative cells have four
17
Q
The rings in the basal body function to
A
Anchor the flagellum to the cell wall
18
Q
Parts of the basal body
A
Rods and rings
19
Q
Pathogenic bacteria
A
Can be identified and classified by differences in their flagellar proteins
20
Q
Significant difference between gram positive and gram negative bacteria
A
Only gran negative cells have a lipopolysaccharide layer (LPS)
21
Q
In gram negative bacteria, a thin layer of peptidoglycan is bonded to lipoproteins?
A
True
22
Q
Which molecule is found in both gram positive and gram negative bacteria
A
N-acetylmurmuric acid
23
Q
Amoxicillin is an antibiotic that inhibits formation of peptide cross-links
A
Amoxicillin inhibits growth of both gram positive and negative cells
24
Porins are present in _____ bacteria because in these organisms, molecules entering the cell must pass through an extra layer of _____
Gram negative, membrane
25
TF? The plasma membrane is a phospholipid bilayer with the hydrophilic phosphate groups oriented toward the inside and outside of the cells
True
26
Which type of solution would cause a cell with a weakened or damaged cell wall to burst as water moved into the cell?
Hypotonic
27
TF? Both cilia and flagella consist of 9 pairs of microtubule doublets arranged in a ring with an additional doublet in the center
True
28
TF? In some eukaryotic cells, the plasma membrane is covered in a sticky glycalyx, which contains carbohydrates
True
29
Which membrane transport mechanism is found in eukaryotic cells but now prokaryotes?
Endocytosis
30
What is found in the cytoplasm of eukaryotes but not prokaryotes?
Cytoskeleton
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TF? In eukaryotes the ribosomes found in chloroplasts of mitochondria 70S ribosomes which are similar in size to prokaryotic ribosomes
True
32
In which eukaryotic organelle are amino acids and fatty acids oxidated?
Peroxosomes
33
Endosymbiosis theory does NOT include
Prokaryotes contain peptidoglycan in their cell walls
34
Why is ATP necessary for active transport?
ATP provides energy to transfer material against its concentration gradient
35
Which type of active transport protein moves two molecules into the cell at the same time?
Symport
36
Which transport protein employs transporters that move molecules in only one direction?
Uniport and symport
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Which type of active transport protein uses one protein to pump two different molecules?
Antiport and symport
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Which of the active transport employs diffusion
Symport
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Which type of transport uses two transport proteins?
Symport
40
Sodium and potassium both need to be pumped against the concentration gradient. Which type of transporter protein would be most effective?
Antiport
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Why ate ATPases associated with active transport proteins?
They provide transport proteins with the energy needed to pump molecules against their concentration gradients
42
Efflux pumps can be used to pump antibiotics out of e cell once they enter to protect the cell. This will be done against the concentration gradient of the antibiotic. Which of the active transport proteins would most likely be used?
Uniport
43
Which which molecule would be blocked by a cell membrane?
Ions
44
Hydrophobic molecules would enter a cell
Through integral transport proteins
45
What is the hallmark of passive transport across cell membranes?
It occurs along an electrochemical gradient and may involve the use of transport proteins
46
A positively charged sodium ion
Would require the use of an integral protein channels to pass through a cell membrane
47
What makes phospholipid membranes good at keeping some molecules out and others freely pass?
They have both hydrophilic and hydrophobic regions
48
Integral proteins are mostly involved in
Transport function
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How does water exit and enter a cell?
By simple diffusion or by use of an integral transport protein
50
A glycoprotein
Is a type of peripheral protein that can be used as a receptor in enzymatic functions
51
How is osmosis different from simple diffusion?
Water movement is driven by the concentration of solutes rather than its own concentration
52
Nonspecific permeases
Allow a variety of molecules to cross the cytoplasmic membrane
53
The principle function of lysosomes
Storage of hydrolytic enzymes
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Which of these is not true of mitochondria?
Generate energy in anaerobic environments
55
Chloroplasts
Evolved from endosymbiosis Cyanobacteria, generate NADPH contain a complex system of internal membranes.
56
The life cycles of eukaryotic microorganisms are distinct from those of prokaryotes because:
Eukaryotes reproduce sexually
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Photolithoautotrophs can be
Prokaryotes or eukaryotes
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Photoorganoheterotrophs can be
Prokaryotes
59
Chemolithoautotrophs can be
Prokaryotes
60
Chemolithoheterotrophs can be
Prokaryotes
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Mix outcrops can be
Eukaryotes or prokaryotes
62
Methyltrophs can be
Prokaryotes
63
It takes energy to acquire nutrients and build bio molecules. Which potential N source will require the greatest energy expenditure to get the N into amino acid?
Dinitrogen
64
Which of these nutrient uptake processes could not be described by the Michaelis-Menton kinetics?
Diffusion (all others use enzymes/ transport proteins)
65
Siderophores assist in the acquisition of which micronutrient?
Iron
66
Things that are true of redox reactions?
Require an electron donor and electron acceptor, oxidation reactions release energy
67
The amount of energy a cell can obtain by oxidizing NADH depends on the molecule used as the terminal electron receptor (oxidant). Say some things about this
Oxygen provides the most energy per mole NADH, if sulfate is used as the terminal acceptor, some of the potential energy from the NADH is trapped as sulfide, which may be available to chemolithoautotrophs, anaerobic heterotrophs need to process more substrate to get the same amount of energy as an aerobic heterotroph
68
A microorganism with a low Km with respect of phosphate uptake will
Will saturate its P uptake pathway at a lower substrate concentration than an organism with a higher Km value
69
Which class of organisms would have optimum growth rate at 62°C?
Thermophiles
70
Aerobic bacteria that have developed (or retain) the availability to continue growing in the absence of molecular oxygen are called
Facultative anaerobes
71
Biofilms
Impact human health, close proximity of microorganisms within a biofilm probably facilitates conjugation, microbes in bio films can work cooperatively to carry out complex tasks, biofilm a usually begin to form when planktonic bacteria attach to a surface.
72
Which type do culture media is best for the growth of most chemoheterotrophic organisms?
Complex media
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Intense activity preparing for population growth occurs in which phase of the bacterial growth curve?
Lag phase
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What causes a bacterial culture to enter the stationary phase?
Harmful changes in pH
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During which phases of the bacterial growth curve are there no changes in the number of living cells?
Lag phase and stationary phase
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During which phases of bacterial growth are there logarithmic changes in population growth?
Lag phase and death phase
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Binary fission in bacteria includes
The plasma membrane and cell wall begin to constrict prior to the formation of the cross-wall
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Bacterial growth is defined as
Increase in bacterial cell population
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In which phase is the rate of cell death equal to the rate of cell growth?
Stationary phase
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Why is cell growth typically graphed logarithmically?
Cell growth is rapid and plotting log number of cells versus the generation on a logarithmic graph produces a linear graph
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Why might cells begin to die at a faster rate than new cells are made?
Lack of nutrients and an increase in cellular waste
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What results when a single bacterium reproduces?
Two genetically identical daughter cells
83
If you begin with six cells, how many cells would you have after three rounds of division?
48
84
Steps in bacterial cell division
Elongation replication of genetic material and splitting of the two daughter cells
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What enables the copied chromosomes to separate during binary fission?
The chromosomes are attached to different parts of the cell membrane, which elongates and thus separates the chromosomes
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Steps of bacterial replication in order
Cell elongation, septum formation, chromosome replication, separation of daughter cells
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What would happen if the septum did not form during binary fission?
The parent cell would have two copies of the chromosome
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Viridiplantae
Land plants and algae. Primary endosymbiotes
89
Cercozoa
Amebas with shells
90
Amebozoa
Amebas and slime molds
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Opisthokonta
Animals, true fungi, micosporidia
92
Excavata
Protista lacking mitochondria
93
Euglenozoa
Protista with discoid cristae (mitochondria)
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Heterokonta
Protista with dissimilar flagella
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Alveolata
Protista with cortical alveoli
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Macronutrients
Elements needed in relatively large quantities. C, O, H, N, S, K, P, Ca, Mg, Fe
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Micronutrients
Elements needed in relatively small quantities. These are usually components of enzymatic cofactors. Mn, Zn, Co, Mo, Ni, Cu
98
Viridiplantae
Land plants and algae. Primary endosymbiotes
99
Cercozoa
Amebas with shells
100
Amebozoa
Amebas and slime molds
101
Opisthokonta
Animals, true fungi, micosporidia
102
Excavata
Protista lacking mitochondria
103
Euglenozoa
Protista with discoid cristae (mitochondria)
104
Heterokonta
Protista with dissimilar flagella
105
Alveolata
Protista with cortical alveoli
106
Macronutrients
Elements needed in relatively large quantities. C, O, H, N, S, K, P, Ca, Mg, Fe
107
Micronutrients
Elements needed in relatively small quantities. These are usually components of enzymatic cofactors. Mn, Zn, Co, Mo, Ni, Cu
108
Autotrophs
Use CO2 as a sole carbon source. This means that they must find a different substance to be oxidized for an electron source because CO2 will be fully oxidized
109
Heterotrophs
Use organic compounds as a carbon source. These molecules, when oxidized also provide a source of electrons
110
Organotrophs
Obtain reducing power by oxidizing organic materials
111
Lithotrophs
Obtain reducing power oxidizing inorganic materials
112
Phototrophs
Use light to generate ATP and NADPH
113
Chemotrophs
Oxidize organic or inorganic molecules to generate ATP
114
Mixotrophs
Organisms that combine heterotrophic and autotrophic (litho or photo) metabolism or can switch between them. Some protests do this
115
Methyltrophs
Heterotrophs able to grow on single carbon molecules (methanol, methane, formaldehyde, formate or carbon monoxide) these are an intermediate between autotrophs and heterotrophs. They are ecologically important in controlling the methane content of the atmosphere.
116
Respiration
The oxidation of carbon to obtain energy and electrons
117
Aerobes
Organisms that use O2 from the environment as their terminal electron acceptor.
118
Anaerobes
Organisms that use an inorganic electron acceptor from their environment. (NO3, SO4, Fe3+)
119
Fermenters
Organisms that use an internal organic molecule as their electron acceptor
120
Facultative anaerobes
Can switch to fermentation when oxygen is not available. Yeast do this
121
Nitrogen metabolism
Needed for proteins, nucleic acids and cell walls. Sources are amino acids, NH4, NO3, Nitrogen fixation of N2 to NH4
122
Phosphorous metabolism
Needed for nucleic acids and phospholipids. Phosphate availability limits metabolism in most habitats.
123
Growth factors
Compounds needed for growth. Amino acids, vitamins, purines and pyrimidines. Generally, free living organisms don't need them but symbiotes do.
124
Permeases
Carry molecules across the membrane; exhibits saturation kinetics (Michaelis-Menten)
125
ABC transporters
Membrane transport coupled directly to ATP hydrolysis
126
Symport and antiport proteins
Substrate transport is directly linked to proton gradient across the membrane
127
Group translocation
Membrane transport coupled to substrate phosphorylation. Sugars are assimilated in conjunction with phosphorylation using phosphoenol pyruvate (PEP) as donor. Phosphorylated sugars are trapped inside the membrane.
128
Michaelis-Menten equation
V=(Vmax x S) / (Km +S)
Km = measure of binding affinity
Vmax= measure of carrier capacity
129
Leeuwenhoek
First to describe microorganisms systematically. He did a bunch of other stuff too
130
Pasteur
Disproved spontaneous generation. Also figured out how fermentation works
131
Koch
Did a lot of work with culture techniques. Famous for Koch's postulates. He also isolated disease-causing bacteria
132
Winogradsky
Work in microbial diversity and chemolithotrophy
133
Beijerinck
Microbial ecology and nitrogen fixation
134
Three domains
Eukarya, archea and bacteria
135
Prok vs euk size
Prokaryotes are generally smaller, but there are exceptions on both ends
136
Oligopeptide
Just a peptide. These link the components of the cell wall
137
Archael cell walls
Do not contain peptidoglycan but are built of protein and polysaccharide
138
Differences in cell wall composition between eukaryotes and prokaryotes
Prokaryotic cell membranes generally have a higher protein content than eukaryotes. They have the bilipid membrane, but do not have sterols, like eukaryotes. Some autotrophic prokaryotes have highly invaginated membranes to increase surface area
139
Chromosome organization
Some bacteria have linear Chromosomes and some have more than one chromosome. The chromosome is anchored to the plasma membrane.
140
Plasmids
Small circular bits of double stranded DNA that can replicate. These are not systematically passed down through cell division, and are a major vector for genetic transfer both within and across lineages.
141
Gram positive Cell wall composition
Gram positive walls have 10-30 layers PC peptidoglycan. Teichoic acids link the layers together. Proteins are linked to peptidoglycan covalently and nom-covalently.
142
Gram negative cell wall composition
Gram negative cell walls have 1-3 layers of peptidoglycan sandwiched between an inner cell membrane and an outer one. The outer membrane is linked covalently to peptidoglycan layer by a lipoprotein. Lipopolysaccharides extend from the outer membrane into the environment. Porins allow small molecules though the outer membrane.
143
Peptidoglycan
Heteropolymer of N-acetylglucosamine (NAG) and N-acetylmurmuric acid (NAM) linked by beta 1,4 glycosidic bonds. Oligopeptides attached to the NAM cross link parallel chains, strengthening the wall by creating a mesh that resists osmotic lysis
144
Peri plasmid space
Contains enzymes associated with nutrient acquisition, peptidoglycan synthesis and electron transport. It is larger in gram negative bacteria.
