Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
|
|
|
1.
|
Metabolism describes a. | the cell's capacity to acquire
energy. | b. | cellular processes used to store
substances. | c. | reactions that break apart nutrients to release
energy. | d. | the elimination of waste products. | e. | all of
these | | |
|
|
|
2.
|
According to the first law of thermodynamics, a. | although energy
in the universe is constant, energy in an earthly system may increase. | b. | the amount of
energy in the universe is constant. | c. | chemical reactions do not create or destroy
energy. | d. | energy can change from one form to
another. | e. | all of these | | |
|
|
|
3.
|
The
second law of thermodynamics holds that a. | matter can be neither created nor
destroyed. | b. | energy can be neither created nor
destroyed. | c. | energy of one form is converted to a less concentrated form
whenever energy is transformed or transferred. | d. | entropy
decreases with time. | e. | none of these | | |
|
|
|
4.
|
Which
of the following statements is false? a. | The universe has a certain amount of
energy. | b. | One form of energy can be converted to other forms of
energy. | c. | Whenever energy conversions occur, some energy is
lost. | d. | Once energy is utilized, it
disappears. | e. | There are differences in the quality of
energy. | | |
|
|
|
5.
|
Which
of the following is an application of the first law of thermodynamics? a. | The level of
entropy increases as time passes. | b. | Living organisms represent an exception to the laws of
energy. | c. | Energy does not increase or decrease. | d. | Fungi and plants
do not make their own energy but derive it from somewhere else. | e. | The amount of
energy found in the compounds on one side of an equation is equal to that on the other
side. | | |
|
|
|
6.
|
Which
statement is NOT true? a. | Because living things maintain organization, entropy does not
apply to living organisms. | b. | The amount of energy in the web of life is greatest among the
plants that capture solar energy. | c. | A state of maximum entropy will never
occur. | d. | Entropy applies at the molecular level as well as at the
organismal level. | e. | Entropy is a measure of the degree of disorder of a
system. | | |
|
|
|
7.
|
The
energy used by living organisms a. | is declining through time. | b. | is derived by
breaking bonds that hold the atoms in organic molecules together. | c. | involves ionic
bonds more often than covalent bonds. | d. | is available only from glucose when it undergoes
respiration. | e. | tends to accumulate in a food chain. | | |
|
|
|
8.
|
The
most common form of low-quality energy released in energy conversions is a. | metabolic. | b. | heat. | c. | entropy. | d. | exergonic emission. | e. | oxidation. | | |
|
|
|
9.
|
ATP
contains a. | alanine. | b. | arginine. | c. | ribose. | d. | tyrosine. | e. | glucose. | | |
|
|
|
10.
|
A
"high-energy bond" a. | absorbs a large amount of free energy when the phosphate group
is attached during hydrolysis. | b. | is formed when ATP is hydrolyzed to ADP and one phosphate
group. | c. | is usually found in each glucose molecule; that is why glucose
is chosen as the starting point for glycolysis. | d. | releases a large
amount of usable energy when the phosphate group is split off during
hydrolysis. | e. | none of these | | |
|
|
|
11.
|
When
NAD+ combines with hydrogen, the NAD+ is a. | reduced. | b. | oxidized. | c. | phosphorylated. | d. | denatured. | e. | none of
these | | |
|
|
|
12.
|
Chemical reactions will reach an equilibrium under which of the following
conditions? a. | There is
sufficient time. | b. | The reactions are reversible. | c. | Product remains
after it is formed. | d. | There are sufficient reactants. | e. | all of
these | | |
|
|
|
13.
|
During enzyme-catalyzed reactions, substrate is a synonym for a. | end
products. | b. | by-products. | c. | enzymes. | d. | reactants. | e. | none of
these | | |
|
|
|
14.
|
Enzymes a. | control the speed of a reaction. | b. | change shapes to
facilitate certain reactions. | c. | may place physical stress on the bonds of the
substrate. | d. | may require cofactors. | e. | all of
these | | |
|
|
|
15.
|
For
an enzyme to function, what kind of energy must be provided? a. | combination | b. | activation | c. | thermal | d. | electrical | e. | solar | | |
|
|
|
16.
|
Enzymes a. | may be secreted by glands. | b. | are usually
molecules of RNA. | c. | are nonspecific with regard to
substrate. | d. | enable some reactions to occur that would never happen without
the availability of enzymes. | e. | will mediate a reversible reaction in one direction
only. | | |
|
|
|
17.
|
Enzymes may be controlled by a. | temperature. | b. | the presence of
chemicals that fit into allosteric sites. | c. | feedback inhibition. | d. | current
metabolic conditions in the cell. | e. | all of these | | |
|
|
|
18.
|
Which
of the following statements is false? a. | Enzymes are highly specific and act on chemicals called
substrates. | b. | Enzymes act as catalysts and speed up chemical reactions within
cells. | c. | Heavy metals such as cadmium and mercury function as coenzymes
or activators of enzymes so they can function. | d. | Most enzymes are
proteins. | e. | Enzymes can become denatured in high
fevers. | | |
|
|
|
19.
|
Allosteric inhibition is generally a result of a. | excess
substrates. | b. | binding of regulatory molecules at another
site. | c. | a change in the temperature of the
system. | d. | a lack of coenzymes. | e. | pH
inhibition. | | |
|
|
|
20.
|
NAD+ and FAD are a. | coenzymes. | b. | electron
acceptors. | c. | reduced forms. | d. | coenzymes and
electron acceptors. | e. | coenzymes, electron acceptors, and reduced
forms. | | |
|
Matching
|
|
|
Choose the one most appropriate answer for each. a. | rate of forward
reaction equals rate of reverse reaction | b. | transfer agent that carries hydrogen and electrons to sites
where hydrogen-containing molecules are being assembled | c. | attaching a
phosphate group by a high-energy bond | d. | an excess of end-product molecules alters the shape of the
first enzyme in the pathway and shuts off that metabolic pathway | e. | part of an
enzyme that binds to the substrate | f. | by binding a regulatory molecule, it changes the activity of a
metabolic pathway | g. | lowers the activation energy of a
reaction | h. | universal energy currency | i. | carries in a
series that help transport electrons | j. | a permanent loss of protein structure | | |
|
|
|
21.
|
allosteric enzyme
|
|
|
22.
|
catalyst
|
|
|
23.
|
phosphorylation
|