Micro Chapter 10 Flashcards
1
Q
The sum of all the chemical reactions occurring in a microbial cell is called A) Metabolism B) Catabolism C) Anabolism D) Oxidation-reduction
A
A
2
Q
Which of the following metabolic reactions is classified as anabolism?
A) Breaking down glucose into pyruvate
B) Using ATP in a cellular reaction
C) Synthesizing proteins from amino acids
D) All of the above
A
C
3
Q
Which of the following metabolic reactions is an example of catabolism?
A) Generating ATP from cellular reactions
B) Breaking down glucose into pyruvate
C) Synthesizing peptidoglycan in the cell wall
D) All of the above
A
B
4
Q
The synthesis of complex biological molecules from simpler precursors is described as A) Chemical work B) Transport work C) Mechanical work D) Potential energy
A
A
5
Q
Movement across cell membranes against an electrochemical gradient in order to take up nutrients, eliminate wastes, and maintain ion balances is an example of A) Chemical work B) Transport work C) Mechanical work D) Potential energy
A
B
6
Q
The energy required for cellular motility and movement of structures within the cell is an example of A) Chemical work B) Transport work C) Mechanical work D) Potential energy
A
C
7
Q
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is the most common form of energy in the microbial cell. A) DNA B) ATP C) Protein D) Hydrolase
A
B
8
Q
Heat given off from one reaction is absorbed during another reaction in the cell. This example demonstrates A) Newton's First Law of Motion B) Newton's Second Law of Motion C) The First Law of Thermodynamics D) The Second Law of Thermodynamics
A
C
9
Q
Entropy in the universe is constantly increasing. This statement describes A) Newton's First Law of Motion B) Newton's Second Law of Motion C) The First Law of Thermodynamics D) The Second Law of Thermodynamics
A
D
10
Q
The amount of energy in a cell available to do work (at constant temperature and pressure) is called A) Enthalpy B) The free energy change C) Equilibrium D) None of the above
A
B
11
Q
Chemical reactions that release energy have A) Positive free energy B) Negative free energy C) No free energy D) None of the above
A
B
12
Q
A chemical reaction is in equilibrium if
A) The forward reaction goes to completion
B) The reverse reaction goes to completion
C) The rates in both directions are equal and no further net change occurs in the concentration of reactants
D) None of the above
A
C
13
Q
In an exergonic reaction, the standard free energy change is A) Positive B) Negative C) Zero D) None of the above
A
B
14
Q
In an endergonic reaction, the standard free energy change is A) Positive B) Negative C) Zero D) None of the above
A
A
15
Q
Which molecule often links endergonic and exergonic reactions in the cell? A) Pyruvate B) Nitrate C) ATP D) Iron
A
C
16
Q
Energy is released as A) A phosphate group is hydrolyzed from ATP B) ADP is phosphorylated C) ATP is phosphorylated D) None of the above
A
A
17
Q
Molecules that have more available electrons to donate are
A) More energy rich
B) Less energy rich
C) Have equal amounts of energy as other molecules
D) None of the above
A
A
18
Q
A reaction in which one molecule donates electrons to another molecule is called A) Hydrolysis B) Oxidation C) Reduction D) All of the above
A
B
19
Q
A molecule with the greatest ability to donate electrons has a standard reduction potential that is A) Negative B) Positive C) Zero D) None of the above
A
A
20
Q
Which of the following molecules has the greatest ability to donate electrons? A) Oxygen B) Nitrate C) Pyruvate D) NADH
A
D
21
Q
The purpose of the electron transport chain (ETC) is to
A) Accumulate electrons to store energy
B) Transfer electrons in order to generate ATP
C) Donate electrons to change membrane potential
D) All of the above
A
B
22
Q
The standard reduction potential of the first electron carrier in the electron transport chain is A) The most positive B) The most negative C) Zero D) None of the above
A
B
23
Q
Where the electron transport chain (ETC) is located in bacterial and archaeal cells? A) Cytoplasm B) Mitochondrial membranes C) Endoplasmic reticulum D) Plasma membrane
A
D
24
Q
Where the electron transport chain (ETC) is located in eukaryotic cells? A) Cytoplasm B) Mitochondrial membrane C) Endoplasmic recticulum D) Plasma membrane
A
B
25
```
Which of the following electron carriers in the eukaryotic ETC has the most negative standard reduction potential?
A) FMN
B) Coenzyme Q
C) Cytochrome c
D) NADH
```
D
26
Enzymes are protein catalysts that are
A) Consumed as they increase the activation energy of a reaction
B) Consumed as they decrease the activation energy of a reaction
C) Not consumed as they increase the activation energy of a reaction
D) Not consumed as they decrease the activation energy of a reaction
D
27
```
If a cofactor is firmly attached to an apoenzyme, it is called a
A) Cofactor
B) Holoenzyme
C) Prosthetic group
D) Coenzyme
```
C
28
The enzyme-substrate complex can lower the activation energy of a reaction by
A) Bringing substrates together at the active site
B) Closing off access to the active site
C) Increasing the concentration of substrate
D) All of the above
A
29
As the concentration of substrate increases, the reaction rate
A) Decreases exponentially until the reaction stops
B) Increases exponentially and reaches an asymptote
C) Decreases linearly
D) Increases linearly
B
30
```
When an enzyme is saturated, it is operating at
A) Terminal velocity
B) Maximum velocity
C) Optimal velocity
D) None of the above
```
B
31
Enzymes with lower Michaelis constants have
A) A greater affinity for the substrate and can catalyze the reaction at lower substrate concentrations
B) A greater affinity for the substrate and requires a higher substrate concentration to catalyze the reaction
C) A lower affinity for the substrate and can catalyze the reaction at lower substrate concentrations
D) A lower affinity for the substrate and requires a higher substrate concentration to catalyze the reaction
A
32
```
Which of the following conditions is most likely to denature an enzyme?
A) High pressure
B) High temperature
C) Low pressure
D) Low temperature
```
B
33
Competitive inhibitors work by
A) Damaging the active site of the enzyme
B) Denaturing the enzyme
C) Competing with the substrate for an enzyme's catalytic site and prevents formation of product
D) All of the above
C
34
```
An example of an antimicrobial that acts through competitive inhibition of an enzyme is
A) Phenol
B) Moist heat sterilization
C) Sulfa drugs
D) Ethylene oxide
```
C
35
```
Catalytic RNA molecules are called
A) Ribosomes
B) Ribozymes
C) Non-competitive inhibitors
D) All of the above
```
B
36
Metabolic pathways can be regulated by
A) Metabolic channeling
B) Regulation of the synthesis of a particular enzyme
C) Direct stimulation or inhibition of the activity of critical enzymes
D) All of the above
D
37
An allosteric enzyme regulates a chemical reaction by
A) Changing the shape of the active site to facilitate binding of the substrate
B) Increasing the substrate concentration available
C) Using an effector molecule to bind to a separate regulatory site that changes the shape of the enzyme
D) None of the above
C
38
```
A process that regulates enzymes by adding or removing a particular chemical group such as phosphate is called
A) Non-competitive inhibition
B) Allosteric regulation
C) Covalent modification
D) Feedback inhibition
```
C
39
```
An end product of a pathway inhibits a pacemaker enzyme in
A) Non-competitive inhibition
B) Allosteric regulation
C) Covalent modification
D) Feedback inhibition
```
D
