Chapter 8 Flashcards
1
Q
The term “metabolism” includes which type(s) of cellular reactions?
A
Both anabolic and catabolic
2
Q
Composed principally of amino acids, and acting as biological catalysts, ______ facilitate metabolic activities of the cell.
A
Ribosomes
3
Q
Most enzymes are a functional type of ______ (a type of macromolecule)
A
Protein
4
Q
An enzyme acts as a biological ______ that alters the rate of a reaction without being changed by the reaction.
A
Catalyst
5
Q
Which statement is FALSE regarding enzymes?
A
Enzymes create reactions.
6
Q
The combination of all reactions within a cell is termed ______.
A
Metabolism
7
Q
The minimum amount of energy required for a reaction to proceed is termed the energy of ______.
A
Activation
8
Q
Biological catalysts are known as
______.
A
Enzymes
9
Q
Which best describes the function of enzymes?
A
Facilitate metabolic pathways
10
Q
Enzymes typically lower the ______ energy needed for a reaction to proceed.
A
Activation
11
Q
A specific molecule on which an enzyme acts is a(n) ______.
A
Substrate
11
Q
Which of the following macromolecules can commonly act as catalysts?
A
Proteins
12
Q
Typically, once an enzyme performs a “job”, it is ______.
A
Ready to “work” again
12
Q
Although they do not create reactions, enzymes are indispensable for life because they:
A
Can speed up the rate of an uncatalyzed reaction by up to 100 trillion fold.
13
Q
What term is used to describe the minimum amount of energy required for a reaction to proceed?
A
Activation energy
14
Q
Specific types of RNA can function as nonenzyme ______.
A
Catalyst
15
Q
Composed principally of amino acids, and acting as biological catalysts, ______ facilitate metabolic activities of the cell.
A
Enzymes
16
Q
A non-functional enzyme which needs a cofactor is called a(n) ______.
A
Apoenzyme
16
Q
Typically, the presence of enzymes ______ the activation energy needed for a reaction to proceed.
A
Lowers
17
Q
A(n) ______ enzyme consists of protein alone, while a(n) ______ enzyme (or holoenzyme) consists of protein and nonprotein components.
A
Simple; conjugated
18
Q
What name is given to the compound upon which an enzyme will act?
A
Substrate
19
Q
Which of the following statements about enzymes are true?
A
Enzymes bind their substrate but are not changed in the reaction.
Enzymes are not consumed in the reaction they catalyze.
Enzymes lower the energy of activation for the reaction that they catalyze.
20
Q
An enzyme with its apoenzyme and cofactors is referred to as a(n) ______, or a conjugated enzyme.
A
Holoenzyme
21
Q
Certain types of the nucleic acid ______ can function as nonprotein enzymes.
A
RNA
22
What term refers to a biological catalyst that lacks an essential cofactor?
Apoenzyme
23
An enzyme with another molecule, such as a metal or vitamin cofactor, bound covalently to it is termed a(n) ______.
Conjugated enzyme
24
Which of the following is needed for an apoenzyme to be fully functional?
Cofactor
25
What can act as cofactors?
Metal ions
Coenzymes
Small organic molecules
26
Besides proteins, which type of molecule has been shown to have catalytic activity?
RNA
26
For an apoenzyme to become a functional holoenzyme, it must ______.
Bind to a cofactor
27
Protein folding determines the 3-D shape in enzymes needed for their______ for a particular substrate.
Specificity
28
The region on an enzyme that binds substrate is the ______ site.
Active, catalytic
29
An organic molecule or inorganic element that may be required for an enzyme to become functional is a(n) ______.
Cofactor
30
A region on an enzyme that is unique for each substrate is the ______ site.
Active, catalytic
30
Which model is sometimes used to describe enzyme-substrate interactions?
Lock-and-key
30
A complex organic molecule, often derived from vitamins, that acts in conjunction with an enzyme is known as a(n) ______.
Coenzyme
30
Which aspect of an enzyme's structure gives rise to the specificity for its substrate?
Folding to produce a 3-D structure
30
Which of the options are names of major classes of enzymes?
Lyase
Hydrolase
Transferase
31
Which best defines an active site?
Region of an enzyme where the substrate binds
31
A catalyst composed of RNA is called a(n) ______.
Ribozyme
31
Which feature of an enzyme is the "most" unique?
Active site
32
Any enzyme that works outside a cell in which it was produced is a(n) ______.
Exoenzyme
32
Any enzyme that works within a cell in which it was produced is a(n) ______.
Endoenzyme
33
Compounds are called ______ when they can be easily denatured, distorted and/or degraded by mild changes to the environment.
Labile
34
What term is used to describe proteins losing their three dimensional structure as a consequence of changes in the environmental conditions such as excessive heat or salt?
Denaturation
35
Which of the following are classes of enzymes?
Transferases
Lyases
Isomerases
36
Changes in environmental conditions can cause the denaturation of cellular enzymes, resulting in:
Blocks to metabolic reactions and ultimately cell death.
37
One evolutionary strategy to deal with an "enzymatic-block" to a particularly necessary metabolic product is to ______.
Have alternative enzymatic methods to synthesize the product
38
Labile means that a substance such as an enzyme is:
Chemically unstable.
39
Which are examples of forms of energy?
Electrical energy
Mechanical energy
Radiant energy
Chemical energy
39
True or false: Cells create energy through metabolism.
False
40
Energy management in a cell most often involves the making or breaking of chemical ______ and the transfer of ______ from one molecule to another.
Bonds; electrons
40
True or false: Metabolic pathways are interconnected.
True
41
The electrons that are released in exergonic pathways are transferred until they reach the:
Final electron acceptor
42
Compounds that are oxidized will ______.
Lose electrons
43
Chemical energy
Bonds of molecules
44
Electric energy
A flow of electrons
45
Radiant energy
Light
46
Mechanical energy
A change in position
47
Atomic energy
Reactions in the nucleus of an atom
48
A redox reaction involves the coupling of which two types of reactions?
Oxidation and reduction
49
Select the ways that cells manage the energy needed for metabolic reactions.
Transferring electrons
Making and breaking chemical bonds
50
Paired reactions where an electron donor transfers electrons to an electron acceptor are called ______ reactions.
Redox
51
What describes the energy flow in cellular metabolism?
Cells convert the energy in nutrients into available energy through metabolism.
52
The production of ATP is often tied to the presence of a final ______ ______.
Electron; acceptor
53
The addition of a phosphate group is referred to as ______.
Phosphorylation
54
Oxidation reactions are coupled with ______ reactions.
Reduction
55
Which term is used to describe the study of the mechanisms of cellular energy release, including catabolic and anabolic pathways?
Bioenergetics
56
In a redox reaction, one compound is ______ and another compound is ______.
Oxidized; reduced
57
The three coupled pathways that many organisms utilize during the catabolism of fuel molecules are ______, the ______ cycle, and the ______ chain.
Glycolysis; Krebs; respiratory/electron transport
58
Electrons are transferred from fuel molecules to oxygen (the terminal electron acceptor) in ______ respiration.
Aerobic
59
The left side of the summary equation for cellular respiration shows ______ ADP.
38
60
Which of the following metabolic pathways begins with glucose and yields two pyruvates?
Glycolysis
61
The second half of glycolysis:
Generates ATP.
62
Which glycolytic reactions require ATP?
1
3
63
In the summary equation for cellular respiration, there are ______ water molecules on the right side of the equation.
6
64
True or false: The pyruvate molecules that form at the end of glycolysis are the first 3-carbon molecules that form in this pathway.
False
65
The multi-step energy-yielding conversion of glucose to pyruvic acid is ______.
Glycolysis
66
Reaction 1 of glycolysis requires an energy source in the form of ______.
ATP
67
Which glycolytic reactions produce G3P?
4
5
68
During the first phase of glycolysis:
There is an ATP investment.
69
During steps 7 and 10 of glycolysis, ATP is generated. What type(s) of reactions occur to generate ATP from ADP and the substrate?
Phosphorylation
Hydrolysis
70
Reaction ______ of glycolysis forms PEPA that has a high-energy phosphate bond.
9
71
DHAP is converted to G3P in reaction ______ of glycolysis.
5
72
What is the first reaction in glycolysis to result in the formation of 3-carbon molecules?
4
73
The location of the Krebs cycle enzymes in eukaryotes is in the ______ matrix, while in prokaryotes the enzymes are found in the ______.
Mitochondrial; cytoplasm
74
ATP is produced during reaction number ______ and reaction number ______ of glycolysis.
7; 10
75
The removal of a ______ molecule from 2-phosphoglyceric acid in reaction 9 of glycolysis produces phosphoenolpyruvic acid and also gives rise to a high-energy ______ bond.
Water; phosphate
76
The Kreb's cycle has ______ steps.
8
77
An iron-containing (heme) protein electron carrier in the last phases of aerobic respiration is a(n) ______.
Cytochrome
78
Complex lll is composed of cytochromes ______ and ______.
b; c1
79
Complex IV catalyzes the reaction between electrons, hydrogen ions, and ______.
Oxygen
80
ATP synthase is stationed in the ______ in close association with the ETS carriers.
Cristae
81
Production of ATP occurs by the process of ______, where hydrogen ions travel down their concentration gradient through channels in ATP synthase complexes.
Chemiosmosis
81
What term is used to describe the process of ATP production from the ETS?
Oxidative phosphorylation
82
Electrons are delivered to______ by Complex lll.
Cytochrome c
83
The production of water in the aerobic electron transport system is catalyzed by ______, which completes the electron transfer process.
IV
84
Which ATP synthase unit can rotate like a motor to pull in protons?
F0
85
ATP ______ is an enzyme in the mitochondrial cristae that harnesses the flux of hydrogen ions across the membrane during oxidative phosphorylation.
Synthase
86
What induces a change in the three-dimensional structure of ATP synthase?
Rotation of the F0 unit
87
At best, cells can generate ______ ATP from the complete oxidation of one glucose molecule during aerobic cellular respiration.
38
87
ATP is synthesized via ______ phosphorylation during the electron transport phase of respiration.
Oxidative
88
The generation of a proton motive force by the pumping of hydrogen ions to the outer side of the membrane during electron transport, and the movement of those hydrogen ions down their electrochemical gradient through the ATP synthase, is ______.
Chemiosmosis
89
The large units of ATP synthase are ______ and ______.
F0; F1
90
The reduction of nitrite to nitric acid, nitrous oxide, and even nitrogen gas is called ______.
Denitrification
91
Fermentation results in the production of ______ aerobic and anaerobic respiration.
Fewer ATP than
92
Protons flow through the F0
portion of ATP synthase via ______.
Diffusion
93
The incomplete breakdown of glucose in the absence of oxygen that yields only a small amount of ATP and produces a variety of byproducts is a process called ______.
Fermentation
94
The production of mixed acids, one being lactic acid, during fermentation is a good definition of ______ fermentation.
Heterolactic
95
Which type of fermentation best describes degradation of pyruvic acid that results in the production of some combination of lactic, acetic, succinic, and formic acids?
Mixed acid
95
The reduction of nitrite to nitrous oxide or nitrogen gas by some species of bacteria is called ______.
Denitrification
96
Which term describes the incomplete breakdown of glucose in the absence of an electron acceptor for the electron transport system?
Fermentation
97
Which type of acidic fermentation produces mixed acid products?
Heterolactic
98
In mixed acid fermentation, pyruvic acid is converted into some combination of ______.
formic acid
lactic acid
acetic acid
succinic acid
99
