BIO 168 Exam 2 Ch 8-10 Questions
with Correct Answers
what term describes the degree to which an element attracts electrons? - ANSWER-
electronegativity
what two terms describe two atoms when they form a bond in which electrons are
completely transferred from one atom to another? - ANSWER-anion and cation
what is a true statement of bonds in a water molecule? - ANSWER-oxygen holds
electrons more tightly than hydrogen does and the net charge is zero
what is an INCORRECT statement about most cellular redox reactions? - ANSWER-
a hydrogen atom is transferred to the atom that loses an electron
what kind of bond is formed when lithium and fluorine combine to form lithium
fluoride? - ANSWER-ionic
gaseous hydrogen burns in the presence of oxygen to form water: 2H2 + O2 --->
2H2O + energy
which molecule is oxidized and what kind of bond is formed? - ANSWER-hydrogen
and polar
what type of reaction breaks the bonds that join the phosphate groups in an ATP
molecule? - ANSWER-hydrolysis
when chemical, transport, or mechanical work is done by an organism, what
happens to the heat generated? - ANSWER-it is lost to the environment
what is true when comparing an unc atalyzed reaction to the same reaction with a
catalyst? - ANSWER-the catalyzed reaction will have the same delta G
in general enzymes are what kinds of molecules? - ANSWER-proteins
enzymes work by...... - ANSWER-reducing Ea
an enzyme.... - ANSWER-is an organic catalyst
what name is given to the reactants in an enzymatically catalyzed reaction? -
ANSWER-substrate
as a result of its involvement in a reaction an enzyme.... - ANSWER-is unchanged
enzymes... - ANSWER-increase the rate of reaction by lowering the activation
energy barrier
, the haber process is typically carried out at a temp of approximately 500C. What
would happen to the rate of the forward reaction if the temp is lowered to 100C? -
ANSWER-the reaction rate would decrease
what would happen to the rate of the forward reaction if the concentration of nitrogen
were decreased? - ANSWER-the reaction rate would decrease
what would increase the rate of the reverse reaction? - ANSWER-increasing the
concentration of ammonia
what will happen to the rates of the forward and reverse reactions when a catalyst is
added? - ANSWER-both forward and reverse rates increase
During a laboratory experiment, you discover that an enzyme-catalyzed reaction has
a G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be
the G for the new reaction? - ANSWER--20kcal/mol
according to the induced fit hypothesis of enzyme catalysis... - ANSWER-the binding
of the substrate changes the shape of the enzyme's active site
some bacteria are metabolically active in hot springs because.... - ANSWER-their
enzymes have high optimal temperatures
increasing the substrate concentration in an enzyme reaction could overcome what?
- ANSWER-competitive inhibition
You have isolated a previously unstudied protein, identified its complete structure in
detail, and determined that it catalyzes the breakdown of a large substrate. You
notice it has two binding sites. One of these is large, apparently the bonding site for
the large substrate; the other is small, possibly a binding site for a regulatory
molecule. What do these findings tell you about the mechanism of this protein? -
ANSWER-it is probably an enzyme that works through allosteric regulation
what is an example of negative feedback? - ANSWER-after you eat insulin
stimulates the lowering of blood sugar
You have discovered an enzyme that can catalyze two different chemical reactions.
What is most likely to be correct? - ANSWER-either the enzyme has two distinct
active sites or the reactants involved in the two reactions are very similar in size and
shape
what term most precisely describes the cellular process of breaking down large
molecules into smaller ones? - ANSWER-catabolism (catabolic pathways)
when ATP releases some energy it also releases inorganic phosphate. what
happens to the inorganic phosphate in the cell? - ANSWER-it may be used to form a
phosphorylated intermediate
the breakdown of large macromolecules as a source for energy and carbon is a -
ANSWER-a catabolic pathway
with Correct Answers
what term describes the degree to which an element attracts electrons? - ANSWER-
electronegativity
what two terms describe two atoms when they form a bond in which electrons are
completely transferred from one atom to another? - ANSWER-anion and cation
what is a true statement of bonds in a water molecule? - ANSWER-oxygen holds
electrons more tightly than hydrogen does and the net charge is zero
what is an INCORRECT statement about most cellular redox reactions? - ANSWER-
a hydrogen atom is transferred to the atom that loses an electron
what kind of bond is formed when lithium and fluorine combine to form lithium
fluoride? - ANSWER-ionic
gaseous hydrogen burns in the presence of oxygen to form water: 2H2 + O2 --->
2H2O + energy
which molecule is oxidized and what kind of bond is formed? - ANSWER-hydrogen
and polar
what type of reaction breaks the bonds that join the phosphate groups in an ATP
molecule? - ANSWER-hydrolysis
when chemical, transport, or mechanical work is done by an organism, what
happens to the heat generated? - ANSWER-it is lost to the environment
what is true when comparing an unc atalyzed reaction to the same reaction with a
catalyst? - ANSWER-the catalyzed reaction will have the same delta G
in general enzymes are what kinds of molecules? - ANSWER-proteins
enzymes work by...... - ANSWER-reducing Ea
an enzyme.... - ANSWER-is an organic catalyst
what name is given to the reactants in an enzymatically catalyzed reaction? -
ANSWER-substrate
as a result of its involvement in a reaction an enzyme.... - ANSWER-is unchanged
enzymes... - ANSWER-increase the rate of reaction by lowering the activation
energy barrier
, the haber process is typically carried out at a temp of approximately 500C. What
would happen to the rate of the forward reaction if the temp is lowered to 100C? -
ANSWER-the reaction rate would decrease
what would happen to the rate of the forward reaction if the concentration of nitrogen
were decreased? - ANSWER-the reaction rate would decrease
what would increase the rate of the reverse reaction? - ANSWER-increasing the
concentration of ammonia
what will happen to the rates of the forward and reverse reactions when a catalyst is
added? - ANSWER-both forward and reverse rates increase
During a laboratory experiment, you discover that an enzyme-catalyzed reaction has
a G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be
the G for the new reaction? - ANSWER--20kcal/mol
according to the induced fit hypothesis of enzyme catalysis... - ANSWER-the binding
of the substrate changes the shape of the enzyme's active site
some bacteria are metabolically active in hot springs because.... - ANSWER-their
enzymes have high optimal temperatures
increasing the substrate concentration in an enzyme reaction could overcome what?
- ANSWER-competitive inhibition
You have isolated a previously unstudied protein, identified its complete structure in
detail, and determined that it catalyzes the breakdown of a large substrate. You
notice it has two binding sites. One of these is large, apparently the bonding site for
the large substrate; the other is small, possibly a binding site for a regulatory
molecule. What do these findings tell you about the mechanism of this protein? -
ANSWER-it is probably an enzyme that works through allosteric regulation
what is an example of negative feedback? - ANSWER-after you eat insulin
stimulates the lowering of blood sugar
You have discovered an enzyme that can catalyze two different chemical reactions.
What is most likely to be correct? - ANSWER-either the enzyme has two distinct
active sites or the reactants involved in the two reactions are very similar in size and
shape
what term most precisely describes the cellular process of breaking down large
molecules into smaller ones? - ANSWER-catabolism (catabolic pathways)
when ATP releases some energy it also releases inorganic phosphate. what
happens to the inorganic phosphate in the cell? - ANSWER-it may be used to form a
phosphorylated intermediate
the breakdown of large macromolecules as a source for energy and carbon is a -
ANSWER-a catabolic pathway
