Chapter 6

Which of the following describes the critical role that ATP plays in cellular metabolism?

ATP serves as an energy shuttle in the cell, coupling exergonic and endergonic reactions.

In most exergonic reactions, the reactants capable of interacting to form products typically must first overcome a thermodynamic barrier known as the

Activation energy of the reaction

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

Add more of the enzyme

The cellular process of synthesizing large molecules from smaller ones is defined as

Anabolism

Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?

As a consequence of growing, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their growth.

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?

Competitive Inhibition

Which of the following is a statement of the first law of thermodynamics?

Energy cannot be created or destroyed.

Energy transformations are always associated with an increase in the

Entropy of the Universe

second law of thermodynamics

Every energy transfer or transformation increases the entropy of the universe.

The mechanism by which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as

Feedback inhibition

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

It is released to the environment

A mutation that results in a single amino acid substitution in the active site of an enzyme

May change the substrate specificity of the enzyme

Increasing the enzyme concentration in an enzymatic reaction could overcome which of the following?

Saturation of the enzyme activity

The induced fit model of enzyme activity suggests which of the following?

The binding of substrate changes the conformation of the active site to bind substrate more tightly.

For living organisms, which of the following is an important consequence of the first law of thermodynamics?

The organism ultimately must obtain all of the necessary energy for life from its environment.

Which of the following is true for all exergonic reactions?

The reaction proceeds with a net release of free energy.

Which of the following is true for anabolic pathways?

They consume energy to build polymers from monomers.

A catabolic pathway may be which of the following?

a set of reactions that release energy that can be used to drive cellular work

ATP structure

adenine, ribose, 3 phosphate groups

The active site of an enzyme is the region that

binds substrates for the enzyme

How do enzymes speed up chemical reactions?

by lowering the activation energy

A noncompetitive inhibitor decreases the rate of an enzymatic reaction by

changing the shape of the enzyme active site.

Which of the following reactions tend to require an input of energy?

dehydration

ATP function

energy carrier in every type of organism (short term storage)

Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as ________ is to ________.

exergonic; endergonic

Which of the following is an exergonic reaction?

hydrolysis of glycogen to release glucose monomers

A severe fever can result in death if not brought under control because

it may alter the tertiary structure of cellular enzymes.

Some bacteria are metabolically active in hot springs because

their enzymes have high optimal temperatures.