Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cellular Biology 201 UNCW > Chapter 8 An Introduction To Metabolism > Flashcards

Chapter 8 An Introduction To Metabolism Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Which of the following is changed by the presence of an enzyme in a reaction?

A

The activation energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which of these statements about enzyme inhibitors is true?

A

The action of inhibitors may be reversible or irreversible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The process of stabilizing the structure of an enzyme in its active form by the binding of a molecule is an example of _____________.

A

Allosteric regulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

An exergonic reaction ________________ free energy, and an end ergo in reaction ________________ free energy.

A

Releases; Absorbs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The primary manner in which cells manage their energy resources in order to do wok is called energy coupling. Which of the following statements accurately defines energy coupling?

A

Exergonic reactions drive endergonic reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which of the following statements about the active site of an enzyme is correct?

A

THe active site may resemble a groove or pocket in the surface of a protein into which the substrate fits.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does ATP drive mechanical work inside a cell?

A

By binding to motor proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What would the aloe of DELTA S be for a chemical reaction in which a molecule is broken down into smaller components?

A

Positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In general, the hydrolysis of ATP drives cellular work by ___________________.

A

Releasing free energy that can be coupled to other reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which of the following statements about enzymes is true?

A

Enzymes speed up the rate of the reaction without changing the DELTA G for the reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

At low pH, a particular enzyme catalyzes a reaction at a high rate. At neutral pH, the enzyme is completely inactive. What statement best explains the difference in how pH affects the function of this enzyme?

A

The enzyme is adapted for low pH but is denatured at neutral pH, leaving it nonfunctional.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which of the following reactions would be endergonic?

A

Glucose + Fructose = Sucrose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What best characterizes the role of ATP in cellular metabolism?

A

The free energy released by ATP hydrolysis that may be coupled to an endergonic process via the formation of a phosphorylated intermediate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

At low temperatures, a particular enzyme catalyzes a reaction, but at a slow rate. At high temperatures, the enzyme is completely inactive. What statement best explains the difference in how temperature affects the function of this enzyme?

A

At low temperatures, there is not enough free energy for the enzyme to function at a high rate, and at high temperatures, the enzyme is remastered, leaving it nonfunctional.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

ATP allosterically inhibits enzymes in ATP-producing pathways. The result of this is called __________________.

A

Feedback inhibition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cells use ATP constantly, but ATP is considered a renewable resource. What process makes this possible?

A

ATP can be regenerated by the addition of a phosphate group to ADP.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which of the following statements is correct regarding kinetic and potential energy?

A

Kinetic energy is associated with the relative motion of abject, and potential energy is the energy that matter possesses because of its location or structure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

As ATP begins to build up in a cell, metabolism slows down. How does this happen?

A

APT acts as an allosteric inhibitor to many of the enzymes involved in metabolism, the us slowing their function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which of the following statements is correct regarding competitive and noncompetitive enzyme inhibitors?

A

Competitive inhibitors bind to the active site of an enzyme while noncompetitive inhibitors bind to an enzyme away form the active site.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does ATP drive transport work inside a cell?

A

By phosphorylation a transport protein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which of the following is an example of the second law of thermodynamics as it applies to biological reactions?

A

The aerobic respiration of one molecule of glucose produces six molecules each of carbon dioxide and water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Enzyme activity is affected by pH because ___________________.

A

High or low pH may disrupt hydrogen bonding or ionic interactions and thus change the shape of the active site.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which of the following statements is correct regarding ATP?

A

The energy in an ATP molecule is released through hydrolysis of one of the phosphate groups.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

If the entropy of a living organism is decreasing, which of the following is most likely to be occurring simultaneously?

A

Energy input into the organism must be occurring to drive the decrease in entropy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which of the following states the relevance of the first lay of thermodynamics to biology?

A

Energy can be freely transformed among different forms as long as the total energy is conserved.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Which of the following is true regarding metabolic pathways?

A

Metabolic pathways consist of a series of reactions, each catalyzed by a different enzyme.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

An exergonic (spontaneous) reaction is a chemical reaction that _____________________.

A

Releases energy when proceeding in the forward direction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which of the following correctly states the relationship between anabolic and catabolic pathways?

A

Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which of the following statements about enzyme function is correct?

A

Enzymes can lower the activation energy of reactions, but they cannot change the equilibrium point because they cannot change the net energy output.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which of the following statements correctly describes cofactors and coenzymes?

A

Both are no protein enzyme helpers; but, most ERC factors are metal ions, and coenzymes are organic molecules that are a specific type of cofactor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

A reaction that occurs spontaneously without an input of energy is ______________________.

A

Exergonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

A reaction that occurs non spontaneously-it requires an input of energy-is ________________________.

A

Endergonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Exergonic reactions result in products that have less free energy than the reactants, thus free energy is released an DELTA G is ______________________.

A

Negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Endergonic reactions result in products that have more free energy than the reactants, thus free energy is absorbed and DELTA G is __________________.

A

Positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

A cell can only carry out an _____________________ reaction by pairing it with an ______________________ reaction such as ATP hydrolysis.

A

Endergonic; Exergonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How does the phosphorylation of glutamic acid (Glu) provide energy for the rest of the reaction to occur?

A

The addition of a phosphate to GLU forms a phosphorylated intermediate with more free energy than GLU. The ammonia can thus displace the phosphate in an exergonic reaction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

A chemical reaction occurs between the amino acids alanine (ALA) and glycine (GLY) forming the compound alanylglycine. The simple conversion reaction of alanine and glycine into this compound is endergonic, with a DELTA G of 6.9 kcal/mol. Therefore, it requires ATP hydrolysis to drove the non spontaneous reaction. Calculate the free energy change for the whole process, applying what you know about ATP hydrolysis.

A

DELTA G = -0.4 kcal/mol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

The molecule that an enzyme reacts with is called the ____________________.

A

Substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Environmental conditions such as ___________________ and ______________________ can affect enzyme function.

A

Temperature; pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Because an enzyme speeds up a chemical reaction, its called a _______________________.

A

Catalyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

A change in an enzyme’s structure that results in it not being able to perform its function is called ______________________.

A

Denaturation

42
Q

An enzyme’s substrate fits into the ___________________ on the enzyme.

A

Active site

43
Q

At which pH did pepsin function the best? In other words, at which pH were the most amino acids produced after 20 min?

A

Pepsin functions best at pH2

44
Q

At which pH did trypsin function the best?

A

Trypsin functioned best at pH7

45
Q

Based on the observations that pepsin’s optimal pH is 2 and trypsin’s optimal pH is 7, what can you conclude about the environment in which these two enzymes function in the body?

A

Pepsin’s environment in the stomach is very acidic, and trypsin’s environment in the small intestines has a neutral pH.

46
Q

What is the ideal temperature for amylase function?

A

Amylase functioned best at 37 degrees C

47
Q

What is the ideal temperature for Taq polymerase function?

A

Taq polymerase functioned best at 75 degrees C

48
Q

What is happening at the molecular level that explains why enzymes function differently at different temperatures?

A

At the ideal temperature, the enzymes and substrate molecules will interact, enervating product molecules as quickly as possible.

At a temperature that is too high, the enzymes will become denatured and lose the ability to react with their substrates.

At a temperature that is too low, the enzymes and substrate molecules wont collide as often since they are moving more slowly.

49
Q

What happens to the amount of disaccharides produced as you increase the initial amount of starch and why?

A

The amount of product increased as the initial starch increased. They enzyme continued to break down the starch.

50
Q

Chemical equilibrium is reached when ________________________________.

A

The forward and reverse reactions occur at the same rate.

51
Q

Which of the following is the strongest evidence that protein structures and functions are correlated?

A

Denatured (unfolded) proteins do not function properly.

52
Q

Conservation of energy refers to the fact that ___________________.

A

energy cannot be created or destroyed but can be converted from one form to another.

53
Q

Chemical energy is a form of ___________________ energy.

A

Potential

54
Q

In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?

A

Cellular respiration

55
Q

What are byproducts of cellular respiration?

A

Heat, carbon dioxide, and water

56
Q

The process of cellular respiration, which converts simple sugars such as glucose into CO2 and water is an example of __________________.

A

A catabolic pathway

57
Q

What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?

A

Hydrolysis

58
Q

The following reaction A—->B+C+heat is a(n) ____________________ reaction.

A

Exergonic

59
Q

A(n) ______________________ reaction occurs spontaneously.

A

Exergonic

60
Q

What reaction requires a net input of energy from its surroundings?

A

Endergonic

61
Q

In cells, what is usually the immediate source of energy for an endergonic reaction?

A

ATP

62
Q

The reaction ADP+P—>ATP is a(n) _________________ reaction

A

Endergonic

63
Q

The energy for an endergonic reaction comes from a(n) _________________ reaction.

A

Exergonic

64
Q

What is the fate of the phosphate group that is removed when ATP is converted to ADP?

A

It is acquired by a reactant in an endergonic reaction

65
Q

What is energy coupling?

A

A description of energy released from an exergonic reaction to drive an endergonic reaction.

66
Q

Which part of the adenosine triphosphate molecule is released when it is hydrolyzed to provide energy for biological reactions?

A

Y-Phosphate (the terminal phosphate)

67
Q

In general, enzymes are what kind of molecules?

A

Proteins

68
Q

Enzymes work by _____________________.

A

Reducing Ea

69
Q

An enzyme _____________________.

A

Is an organic catalyst

70
Q

What name is given to the reactants in an enzymatically catalyzed reaction?

A

Substrate

71
Q

As a result of its involvement in a reaction, an enzyme __________________.

A

Is uncharged

72
Q

Enzymes are described as catalysts, which means that they _______________________.

A

Increase the rate of a reaction without being consumed by the reaction.

73
Q

The binding of a compound to an enzyme is a served to slow down or stop the rate of the reaction catalyzed by the enzyme. Increasing the substrate concentration reduces the inhibitory effects of this compound. Which of the following could account for this observation?

A

The compound is a competitive inhibitor.

74
Q

Which of the following is a characteristic feature of anabolic pathways?

A

They consume energy to build up polymers from monomers

75
Q

Which of the following types of reactions would decrease the entropy within a cell?

A

Anabolic reactions

76
Q

Select the correct statement about chemical energy, a term used by biologists to refer to potential energy available for release in a chemical reaction.

A

Light energy is converted to chemical energy during photosynthesis

77
Q

The process of cellular respiration, which converts simple sugars such as glucose into CO2 and water is an example of _______________________.

A

A catabolic pathway

78
Q

Catabolism is to anabolism as ________________ is to __________________.

A

Exergonic; endergonic

79
Q

The mathematical expression for the change in free energy of a system is DELTA G = DELTA H - T DELTA S. Which of the following statements best describes a term in this equation?

A

DELTA G is the change in energy

80
Q

Which of the following statements best describes an exergonic reaction?

A

The reaction proceeds with a net release of free energy

81
Q

Which of the following terms best describes a chemical reaction for which DELTA G is positive?

A

Endergonic

82
Q

Which of the following statement best describes a system at chemical equilibrium?

A

The system can do no work

83
Q

The relationship between the breakdown of macromolecules and the biosynthesis of macromolecules is most similar to the relationship between which of the following pairs of terms?

A

Exergonic and endergonic

84
Q

Which of the following statements best describes why hydrolysis reactions occur more readily in solution than dehydration reactions do?

A

Hydrolysis reactions are exergonic and increase entropy of the system

85
Q

Which of the following metabolic processes can occur without a net influx of energy from some other process?

A

C6H12O6+6O2+6H2O

86
Q

Which of the following statements best describes the central role that ATP plays in cellular metabolism?

A

ATP provides energy coupling between exergonic and endergonic reactions.

87
Q

Which of the following statements best describes catabolic path ways?

A

They are exergonic and provide energy that can be used to produce ATP from ADP and Pi

88
Q

When chemical, transport, or mechanical work is performed by an organism, what happens to the heat that is generated?

A

It is lost to the environment

89
Q

The DELTA G of ATP hydrolysis in a test tube under standard conditions is -7.3kcal/mol. The DELTA G for the reaction A+B=C under the same conditions is +4.0 kcal/mol. What is the over all free-energy for the coupled reaction under these conditions?

A

-3.3 kcal/mol

90
Q

If an enzyme in solution is saturated with substrate, the more effective way to obtain a faster yield of products is to _____________________.

A

Add more of the enzyme.

91
Q

Some bacterial are metabolically active in hot springs because

A

Their enzymes have high optimal temperatures.

92
Q

Which of the following statements best describes enzyme function?

A

Enzymes increase the rate of chemical reactions by lowering activation energy barriers.

93
Q

A clasping handshake may be used as an analogy for an enzyme-catalyzed reaction because it represents the specific manner in which an enzyme _______________________.

A

Binds substrate

94
Q

What is the name of the barrier that must be overcome before products are formed in a spontaneous reaction?

A

Activation energy

95
Q

Which of the following statements best describes induced fit?

A

Binding of substrate to the activation site changes the shape of the active site of an enzyme.

96
Q

How does a non competitive inhibitor decrease the rate of an enzyme-catalyzed reaction?

A

By binding to an almost Eric site, thus changing the shape of the active site of the enzyme.

97
Q

Which of the following statements best describes how addition of a catalyst will affect a chemical reaction?

A

Th3e catalyzed reaction will have the same DELTA G as the un-catalysed reaction

98
Q

An enzyme-catalyzed reaction has a DELTA G of -20 kcal/mol under standard conditions. What will be the DELTA G for the reaction if the amount of enzyme is doubled?

A

-20kcal/mol

99
Q

Disruption of the active site of an enzyme would most likely result in which of the following?

A

A decreased ability of the enzyme to bond substrates

100
Q

In the citric acid cycle, succinct dehydration catalyzes the conversion of succinct to fumarate. This reaction is inhibited by malonate, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Which of the following statements best describes the role played by molecules described in the reaction?

A

Succinate dehydrogenase is the enzyme, and malonate is the substrate in the reaction.

Cellular Biology 201 UNCW (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions