Question 1

Which of the following statements about metabolic pathways is FALSE?

Accepted Answer

A)  The enzymes of some pathways are segregated inside specific organelles. 
B)  The enzymes of some pathways are embedded in specific membranes. 
C)  The enzymes of most pathways allow intermediate products to accumulate. 
D)  Exergonic reactions in the pathway will pull forward preceding reactions. 
E)  The products from exergonic reactions will push along subsequent reactions. 
A)  The enzymes of some pathways are segregated inside specific organelles. 
B)  The enzymes of some pathways are embedded in specific membranes. 
C)  The enzymes of most pathways allow intermediate products to accumulate. 
D)  Exergonic reactions in the pathway will pull forward preceding reactions. 
E)  The products from exergonic reactions will push along subsequent reactions. C

Question 2

Which of the following statements about sucrose synthesis is FALSE?

Accepted Answer

A)  Under standard thermodynamic conditions sucrose synthesis is endergonic. 
B)  In the cell, sucrose synthesis is endergonic. 
C)  In the cell, sucrose synthesis involves the phosphorylation of glucose. 
D)  In the cell, sucrose synthesis involves the phosphorylation of fructose. 
E)  In the cell, sucrose synthesis is coupled with ATP hydrolysis. 
A)  Under standard thermodynamic conditions sucrose synthesis is endergonic. 
B)  In the cell, sucrose synthesis is endergonic. 
C)  In the cell, sucrose synthesis involves the phosphorylation of glucose. 
D)  In the cell, sucrose synthesis involves the phosphorylation of fructose. 
E)  In the cell, sucrose synthesis is coupled with ATP hydrolysis. B

Question 3

When an atom is reduced, it loses electrons.

Accepted Answer

A) True 
 B)False  False

Question 4

For most enzyme catalyzed reactions, the rate approximately doubles for each 5C increase in temperature.

Accepted Answer

A) True 
 B)False

Question 5

A substrate binds to its enzyme at a location called the ______ site.

Accepted Answer

A)  coenzyme 
B)  substrate 
C)  active 
D)  polypeptide 
E)  cofactor 
A)  coenzyme 
B)  substrate 
C)  active 
D)  polypeptide 
E)  cofactor

Question 6

Denaturation of an enzyme refers to the:

Accepted Answer

A)  proper arrangement of the enzyme in a metabolic pathway. 
B)  improper arrangement of the enzyme in a metabolic pathway. 
C)  loss of the enzyme's proper shape. 
D)  formation of the enzyme's proper shape. 
E)  formation of a new isozyme for that enzyme. 
A)  proper arrangement of the enzyme in a metabolic pathway. 
B)  improper arrangement of the enzyme in a metabolic pathway. 
C)  loss of the enzyme's proper shape. 
D)  formation of the enzyme's proper shape. 
E)  formation of a new isozyme for that enzyme.

Question 7

The heat released in the exhaust of an engine can produce work.

Accepted Answer

A) True 
 B)False

Question 8

All enzymes are proteins.

Accepted Answer

A) True 
 B)False

Question 9

Plants, like humans, are unable to synthesize all of their required vitamins.

Accepted Answer

A) True 
 B)False

Question 10

A principal factor regulating enzyme activity in cells is the amount of substrate available.

Accepted Answer

A) True 
 B)False

Question 11

ATP + H2O → ADP + phosphate

Accepted Answer

A)  phosphorylase 
B)  ATPase 
C)  ADPase 
D)  kinase 
E)  phosphatase 
A)  phosphorylase 
B)  ATPase 
C)  ADPase 
D)  kinase 
E)  phosphatase

Question 12

An exergonic reaction:

Accepted Answer

A)  is a reaction in which the potential energy of the final state is less than that of the initial state. 
B)  does not take place spontaneously. 
C)  requires an input of energy from the outside. 
D)  has a positive free-energy change. 
E)  has a positive ΔG value. 
A)  is a reaction in which the potential energy of the final state is less than that of the initial state. 
B)  does not take place spontaneously. 
C)  requires an input of energy from the outside. 
D)  has a positive free-energy change. 
E)  has a positive ΔG value.

Question 13

Isozymes are:

Accepted Answer

A)  RNA molecules that catalyze metabolic reactions. 
B)  identical coenzymes that require different metal ions. 
C)  identical coenzymes located in different parts of the cell. 
D)  different enzymes that catalyze identical reactions. 
E)  identical enzymes that catalyze different reactions. 
A)  RNA molecules that catalyze metabolic reactions. 
B)  identical coenzymes that require different metal ions. 
C)  identical coenzymes located in different parts of the cell. 
D)  different enzymes that catalyze identical reactions. 
E)  identical enzymes that catalyze different reactions.

Question 14

In a NAD+ molecule, a pyrophosphate bridge joins:

Accepted Answer

A)  two nicotinamide molecules. 
B)  two adenine molecules. 
C)  one ribose molecule with one nicotinamide molecule. 
D)  two ribose molecules. 
E)  one ribose molecule with one adenine molecule. 
A)  two nicotinamide molecules. 
B)  two adenine molecules. 
C)  one ribose molecule with one nicotinamide molecule. 
D)  two ribose molecules. 
E)  one ribose molecule with one adenine molecule.

Question 15

Which of the following statements concerning the effect of pH on enzyme activity is FALSE?

Accepted Answer

A)  Enzyme shape changes as the pH changes. 
B)  The pH affects positively-charged amino acids. 
C)  The pH affects negatively-charged amino acids. 
D)  The binding capacity of an enzyme is affected by pH. 
E)  Enzymes are always present at their pH optimum. 
A)  Enzyme shape changes as the pH changes. 
B)  The pH affects positively-charged amino acids. 
C)  The pH affects negatively-charged amino acids. 
D)  The binding capacity of an enzyme is affected by pH. 
E)  Enzymes are always present at their pH optimum.

Question 16

In all naturally occurring processes:

Accepted Answer

A)  ΔH is positive. 
B)  ΔH is negative. 
C)  ΔS is positive. 
D)  ΔS is negative. 
E)  ΔG is negative. 
A)  ΔH is positive. 
B)  ΔH is negative. 
C)  ΔS is positive. 
D)  ΔS is negative. 
E)  ΔG is negative.

Question 17

The overall charge in energy that determines the course of a chemical reaction is the free-energy charge, ΔG.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following equations relating enthalpy, entropy, and free energy is correct?

Accepted Answer

A)  ΔS = ΔH - T ΔG 
B)  ΔH = ΔG - T ΔS 
C)  ΔS = ΔG + T ΔH 
D)  ΔG = ΔH - T ΔS 
E)  ΔG = ΔH + T ΔS 
A)  ΔS = ΔH - T ΔG 
B)  ΔH = ΔG - T ΔS 
C)  ΔS = ΔG + T ΔH 
D)  ΔG = ΔH - T ΔS 
E)  ΔG = ΔH + T ΔS

Question 19

Which of the following is a phosphorylation reaction catalyzed by a kinase in plant cells?

Accepted Answer

A)  ATP + glucose → glucose phosphate + ADP 
B)  Fructose phosphate + ADP → fructose + ATP 
C)  Glucose phosphate + ADP → glucose + ATP 
D)  ATP + H2O → ADP + phosphate 
E)  ADP + phosphate → ATP + H2O 
A)  ATP + glucose → glucose phosphate + ADP 
B)  Fructose phosphate + ADP → fructose + ATP 
C)  Glucose phosphate + ADP → glucose + ATP 
D)  ATP + H2O → ADP + phosphate 
E)  ADP + phosphate → ATP + H2O

Question 20

In feedback inhibition, the ______ enzyme in a metabolic pathway is inhibited by the ___________.

Accepted Answer

A)  last; first substrate 
B)  last; end product 
C)  first; cofactor 
D)  first; first substrate 
E)  first; end product 
A)  last; first substrate 
B)  last; end product 
C)  first; cofactor 
D)  first; first substrate 
E)  first; end product

Exam 5: The Flow of Energy

Which of the following statements about metabolic pathways is FALSE?

Which of the following statements about sucrose synthesis is FALSE?

When an atom is reduced, it loses electrons.

For most enzyme catalyzed reactions, the rate approximately doubles for each 5C increase in temperature.

A substrate binds to its enzyme at a location called the ______ site.

Denaturation of an enzyme refers to the:

The heat released in the exhaust of an engine can produce work.

All enzymes are proteins.

Plants, like humans, are unable to synthesize all of their required vitamins.

A principal factor regulating enzyme activity in cells is the amount of substrate available.

ATP + H2O → ADP + phosphate

An exergonic reaction:

Isozymes are:

In a NAD+ molecule, a pyrophosphate bridge joins:

Which of the following statements concerning the effect of pH on enzyme activity is FALSE?

In all naturally occurring processes:

The overall charge in energy that determines the course of a chemical reaction is the free-energy charge, ΔG.

Which of the following equations relating enthalpy, entropy, and free energy is correct?

Which of the following is a phosphorylation reaction catalyzed by a kinase in plant cells?

In feedback inhibition, the ______ enzyme in a metabolic pathway is inhibited by the ___________.

Botany: an Introduction

The Molecular Composition of Plant Cells

The Plant Cell and the Cell Cycle

The Movement of Substances Into and Out of Cells

Respiration

Photosynthesis, Light, and Life

Sexual Reproduction and Heredity

The Chemistry of Heredity and Gene Expression

Recombinant Dna Technology, Plant Biotechnology, and Genomics

The Process of Evolution

Systematics: the Science of Biological Diversity

Prokaryotes and Viruses

Fungi

Protists: Algae and Heterotrophic Protists

Bryophytes

Seedless Vascular Plants

Gymnosperms

Introduction to the Angiosperms

Evolution of the Angiosperms

Plants and People

Early Development of the Plant Body

Cells and Tissues of the Plant Body

The Root: Structure and Development

The Shoot: Primary Structure and Development

Secondary Growth in Stems

Regulating Growth and Development: the Plant Hormones

External Factors and Plant Growth

Plant Nutrition and Soils

The Movement of Water and Solutes in Plants

The Dynamics of Communities and Ecosystems

Global Ecology

Filters

ATP + H₂O → ADP + phosphate

In feedback inhibition, the enzyme in a metabolic pathway is inhibited by the _____.