MMBIO 221 Exam 3 Complete Questions
with Answers
Coupling occurs when the energy released by an exergonic reaction is - -
Used to drive an endergonic reaction
- The reaction shown below is an enzymatically catalyzed redox reaction
that occurs in fermentation. In this reaction, an enzyme performs an
oxidation reaction with a concomitant reduction reaction. Which of the
substrates and products produced by the reaction is being reduced (that is,
accepting electrons)? - -pyruvate
- Which of the following statements is false? - -Enzymes are consumed by
the reactions they catalyze.
- Enzymes act as biological ________________. - -catalysts
- For any oxidation reaction in cells, there is always a concomitant reduction
reaction. - -True
- The role of molecules such as NAD+ and FAD+ in cells is to - -transfer
electrons between reactions.
- Molecules, such as glucose, function as fuels in catabolic reactions. At a
fundamental level, WHAT ROLE DOES FUEL HAVE IN CATABOLISM? - -It is an
electron donor
- The reaction below shows the conversion of phosphoenolpyruvate (PEP) to
pyruvate and the simultaneous phosphorylation of ADP to make ATP. Of the
following terms, which best describes the type of reaction when ADP is
phosphorylated? - -Exergonic reaction
- For any oxidation reaction in cells, there is always a concomitant reduction
reaction.
True - -True
- Molecules, such as oxygen, function as oxidants in catabolic reactions. At a
fundamental level, what role does an OXIDANT have in catabolism? - -It is an
electron acceptor
- Enzymes make reactions go ______________ by ______________ the activation
energy of the reaction. - -Faster; Lowering
, - In enzymatic reactions, enzymes react with substrates to produce an
enzyme-substrate complex and then the reaction proceeds and products are
formed. This is represented in the figure below.
Which reaction, A or B, is most likely to be the rate-limiting step in an
enzymatic reaction? - -A
- The site into which substrates fit in an enzyme during a reaction is known
as the ____________ site. - -active
- An exergonic reaction is one that - -the reactants have more energy than
the products
- An endergonic reaction is one that - -the products have more energy than
the reactants
- - -
- The reaction below shows the conversion of phosphoenolpyruvate to
pyruvate and the simultaneous phosphorylation of ADP to make ATP. Of the
following terms, which best describes the type of reaction where
phosphoenolpyruvate is converted to pyruvate? - -Substrate level
phosphorylation
- The enzyme that phosphorylates ADP using a chemiosmotic proton motive
force is - -ATP synthase
- Fermentation is a wasteful process because the cell secretes carbon-
carbon bonds and also wastes - -electrons temporarily stored in NADH
- In the tricarboxylic acid (TCA) cycle, carbon atoms (as CO2) are
sequentially broken off of molecules such as isocitrate. The electrons are
passed to NAD+ making NADH. This electron transport molecule then
transfers its electrons to the electron transport chain and a proton motive
force (PMF) is established. The PMF is then used to generate ATP using ATP
synthase. Of the following terms, which best describes the type of reaction
where ATP is generated? - -Oxidative phosphorylation
- Lactic acid and ethanol are the only substances produced by fermenting
microorganisms. - -False
- In aerobic cellular respiration, which generates more ATP, substrate-level
phosphorylation or oxidative phosphorylation? - -Oxidative phosphorylation
- During oxidative phosphorylation, electrons are moved through the
electron transport chain to a terminal electron acceptor. What other critically
with Answers
Coupling occurs when the energy released by an exergonic reaction is - -
Used to drive an endergonic reaction
- The reaction shown below is an enzymatically catalyzed redox reaction
that occurs in fermentation. In this reaction, an enzyme performs an
oxidation reaction with a concomitant reduction reaction. Which of the
substrates and products produced by the reaction is being reduced (that is,
accepting electrons)? - -pyruvate
- Which of the following statements is false? - -Enzymes are consumed by
the reactions they catalyze.
- Enzymes act as biological ________________. - -catalysts
- For any oxidation reaction in cells, there is always a concomitant reduction
reaction. - -True
- The role of molecules such as NAD+ and FAD+ in cells is to - -transfer
electrons between reactions.
- Molecules, such as glucose, function as fuels in catabolic reactions. At a
fundamental level, WHAT ROLE DOES FUEL HAVE IN CATABOLISM? - -It is an
electron donor
- The reaction below shows the conversion of phosphoenolpyruvate (PEP) to
pyruvate and the simultaneous phosphorylation of ADP to make ATP. Of the
following terms, which best describes the type of reaction when ADP is
phosphorylated? - -Exergonic reaction
- For any oxidation reaction in cells, there is always a concomitant reduction
reaction.
True - -True
- Molecules, such as oxygen, function as oxidants in catabolic reactions. At a
fundamental level, what role does an OXIDANT have in catabolism? - -It is an
electron acceptor
- Enzymes make reactions go ______________ by ______________ the activation
energy of the reaction. - -Faster; Lowering
, - In enzymatic reactions, enzymes react with substrates to produce an
enzyme-substrate complex and then the reaction proceeds and products are
formed. This is represented in the figure below.
Which reaction, A or B, is most likely to be the rate-limiting step in an
enzymatic reaction? - -A
- The site into which substrates fit in an enzyme during a reaction is known
as the ____________ site. - -active
- An exergonic reaction is one that - -the reactants have more energy than
the products
- An endergonic reaction is one that - -the products have more energy than
the reactants
- - -
- The reaction below shows the conversion of phosphoenolpyruvate to
pyruvate and the simultaneous phosphorylation of ADP to make ATP. Of the
following terms, which best describes the type of reaction where
phosphoenolpyruvate is converted to pyruvate? - -Substrate level
phosphorylation
- The enzyme that phosphorylates ADP using a chemiosmotic proton motive
force is - -ATP synthase
- Fermentation is a wasteful process because the cell secretes carbon-
carbon bonds and also wastes - -electrons temporarily stored in NADH
- In the tricarboxylic acid (TCA) cycle, carbon atoms (as CO2) are
sequentially broken off of molecules such as isocitrate. The electrons are
passed to NAD+ making NADH. This electron transport molecule then
transfers its electrons to the electron transport chain and a proton motive
force (PMF) is established. The PMF is then used to generate ATP using ATP
synthase. Of the following terms, which best describes the type of reaction
where ATP is generated? - -Oxidative phosphorylation
- Lactic acid and ethanol are the only substances produced by fermenting
microorganisms. - -False
- In aerobic cellular respiration, which generates more ATP, substrate-level
phosphorylation or oxidative phosphorylation? - -Oxidative phosphorylation
- During oxidative phosphorylation, electrons are moved through the
electron transport chain to a terminal electron acceptor. What other critically
