Quiz 6
Ch 6
Name________________________
Remote # ____________
reaction
d. elevating the activation energy of the
reaction
1. Define the properties and behavior of
energy. The first law states that energy
__________.
a. equals mass times the speed of light,
squared (that is, E = mc2)
b. can be created by thermonuclear
explosions
c. cannot be created or destroyed but
can be changed from one form into
another
d. is the basic structure of the universe
5. ATP is well suited to its role as an
energy-carrier molecule in cells because
_________.
a. the covalent bond between the last
two phosphates can be broken to
release substantial amounts of energy
b. it contains covalent bonds
c. it is small and can fit into a lot of
places in the cell
d. the covalent bonds between the last
two phosphates are high-energy bonds
that can absorb a substantial amount of
energy when the bonds are broken
2. The second law of thermodynamics
relates the organization of matter to
energy. It states that unless additional
energy is acquired, the orderliness of a
system tends to __________, whereas
entropy __________.
a. increase, decreases
b. decrease, increases
c. stay the same, increases
d. decrease, stays the same
6. A substance that is acted upon by an
enzyme to produce a product is called
a(n) __________.
a. allosteric inhibitor
b. coenzyme
c. substrate
d. electron carrier
.
7. Which of the following situations
illustrates the coupling of exergonic to
endergonic reactions in cells?
a. the production of ATP by breakdown
of glucose
b. the active transport of sodium into the
cell
c. the movement of a muscle powered
by the hydrolysis of ATP
d. All of the above are correct.
3. In endergonic reactions, __________.
a. the reactants have more potential
energy than the products
b. energy is released
c. a net input of energy is not required
d. all of the above
e. none of the above
4. Enzymes are a class of proteins that
catalyze chemical reactions in cells. Like
all other catalysts, they speed up
chemical reactions by __________.
a. making the reaction endergonic
b. releasing energy for the reaction
c. lowering the activation energy of the
8. The amino acid threonine is
converted to isoleucine by a sequence
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of five enzymatic reactions. When
isoleucine levels are high, the first
reaction in this sequence is “turned off.”
This is an example of __________.
a. substrate activation
b. feedback inhibition
c. competitive inhibition
d. coenzyme activation
9. Why do most reactions occur more
rapidly at high temperature?
a. Molecules move more rapidly at
higher temperatures.
b. Collisions between molecules are
more frequent.
c. Collisions will be hard enough to force
electron shells to interact.
d. All of the above are correct.
10. Enzyme regulation can be precisely
controlled through a variety of
mechanisms such as __________.
a. production of an inactive form of an
enzyme that will become activated only
when needed
b. using a coenzyme that is necessary
for function
c. binding of a competitive inhibitor to
the active site
d. all of the above
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