BMSC 230 ALL QUIZZES WITH
COMPLETE SOLUTIONS
Which of the statements below about metabolism is INCORRECT?
Metabolism refers to the sum total of chemical reactions that lead to the breakdown or
synthesis of biomolecules.
Most anabolic reactions, such as building larger molecules from small building block
molecules, do not require the input of energy.
The energy produced from catabolism is captured in the form of ATP, the energy
currency of the cell.
Metabolism is the sum total of catabolism and anabolism. - Correct Answers -Most
anabolic reactions, such as building larger molecules from small building block
molecules, do not require the input of energy.
Which of the statements below about an amphibolic pathway is CORRECT?
It has both positively- and negatively-charged intermediates.
It can function both catabolically and anabolically.
It is always interconnected with another pathway.
It can proceed spontaneously in either direction. - Correct Answers -It can function both
catabolically and anabolically.
Consider the following reaction, then choose the CORRECT statement about it:
phosphoenolpyruvate + ADP ←→ pyruvate +ATP ΔG = -17 kJ/mol
The Keq of this reaction is likely around 1.0.
This reaction can readily proceed in either direction in the cell depending on the
concentrations of phosphoenolpyruvate and pyruvate.
Correct!
This reaction strongly favors the forward direction i.e. the production of pyruvate.
This reaction strongly favors the reverse reaction i.e. the production of
phosphoenolpyruvate because the degradation of ATP releases much energy. - Correct
Answers -This reaction strongly favors the forward direction i.e. the production of
pyruvate.
Which statement about ATP is INCORRECT?
, One reason why the hydrolysis of ATP releases so much energy is that the electrostatic
repulsion is reduced.
When we digest and metabolize fuels, the energy released is captured primarily in the
form of ATP.
ATP has two high-energy, ester bonds.
While ATP is the main energy currency of the cell, the three other nucleoside
triphosphates (GTP, UTP, CTP) are sometimes used to provide ener - Correct Answers
-ATP has two high-energy, ester bonds
Consider the following reaction:
Which of the following statements about this reaction is INCORRECT?
Correct!
This is a redox reaction in which glutamate is reduced to α-ketoglutarate.
The electrons that are lost in this reaction are captured in the form of NADH.
NAD+ is an oxidizing agent in this reaction.
While no ATP is directly formed in this reaction, ATP will be produced when NADH
donates its electrons in a process known as oxidative phosphorylation. - Correct
Answers -This is a redox reaction in which glutamate is reduced to α-ketoglutarate.
Which of the following molecules is an activated carrier of electrons used in many
biosynthetic reactions?
Coenzyme A
NADPH
NADH
FADH2 - Correct Answers -NADPH
Which of the following completes this sentence accurately?
Many activated carriers:
participate in isomerase reactions.
are small inorganic molecules that function as coenzymes.
are derived from B vitamins.
are derived from vitamin C. - Correct Answers -Are derived from B vitamins
From a metabolic perspective, why is high-fructose corn syrup, which is used widely in
the food industry, a concern?
Fructose is quickly phosphorylated to fructose-6-P, which leads to too much flux
through glycolysis and ends up causing too much fat synthesis.
Since there is no enzyme that can phosphorylate fructose, it can't be metabolized by
glycolysis, but is rather stored as sucrose which is toxic.
, Fructose is rapidly metabolized by the liver in an unregulated fashion through to
pyruvate. Some of the pyruvate is converted to ethanol.
Correct!
Fructose is metabolized in a way that bypasses the main regulatory point in glycolysis.
This leads to excess flow through glycolysis, and ultimately too much fat synthesis. -
Correct Answers -Fructose is metabolized in a way that bypasses the main regulatory
point in glycolysis. This leads to excess flow through glycolysis, and ultimately too much
fat synthesis.
What is the net number of ATP molecules produced for every one molecule of glucose
metabolized through glycolysis?
2
3
4
1 - Correct Answers -2
The conversation of pyruvate to this biomolecule produces the most energy:
Lactate
Acetyl CoA
Ethanol
Phosphoenolpyruvate - Correct Answers -Acetyl CoA
Which statement about lactose metabolism is CORRECT?
Lactose intolerance results from an enzyme deficiency that prevents galactose from
being converted to a glycolytic intermediate.
Correct!
The galactose that is produced from lactose degradation is metabolized through
several reactions to glucose-6-P.
Galactose is phosphorylated to galactose-6-P which is then converted to glucose-6-P
by an epimerase enzyme which changes the position of an hydroxyl group.
The conversation of pyruvate to lactate occurs mainly under aerobic conditions. -
Correct Answers -The galactose that is produced from lactose degradation is
metabolized through several reactions to glucose-6-P.
Which of the following statements about glycolysis is CORRECT?
The overall free energy change for the pathway is highly positive and thus only flows in
one direction, towards the production of pyruvate.
Since there are two steps in the pathway where ATP are consumed and four steps
where it is produced, the net production of ATP is two per glucose molecule.
Correct!
Some individual reactions in the pathway are reversible.
The phosphorylation of glucose to glucose-6-P is an example of substrate-level
phosphorylation. - Correct Answers -Some individual reactions in the pathway are
reversible.
COMPLETE SOLUTIONS
Which of the statements below about metabolism is INCORRECT?
Metabolism refers to the sum total of chemical reactions that lead to the breakdown or
synthesis of biomolecules.
Most anabolic reactions, such as building larger molecules from small building block
molecules, do not require the input of energy.
The energy produced from catabolism is captured in the form of ATP, the energy
currency of the cell.
Metabolism is the sum total of catabolism and anabolism. - Correct Answers -Most
anabolic reactions, such as building larger molecules from small building block
molecules, do not require the input of energy.
Which of the statements below about an amphibolic pathway is CORRECT?
It has both positively- and negatively-charged intermediates.
It can function both catabolically and anabolically.
It is always interconnected with another pathway.
It can proceed spontaneously in either direction. - Correct Answers -It can function both
catabolically and anabolically.
Consider the following reaction, then choose the CORRECT statement about it:
phosphoenolpyruvate + ADP ←→ pyruvate +ATP ΔG = -17 kJ/mol
The Keq of this reaction is likely around 1.0.
This reaction can readily proceed in either direction in the cell depending on the
concentrations of phosphoenolpyruvate and pyruvate.
Correct!
This reaction strongly favors the forward direction i.e. the production of pyruvate.
This reaction strongly favors the reverse reaction i.e. the production of
phosphoenolpyruvate because the degradation of ATP releases much energy. - Correct
Answers -This reaction strongly favors the forward direction i.e. the production of
pyruvate.
Which statement about ATP is INCORRECT?
, One reason why the hydrolysis of ATP releases so much energy is that the electrostatic
repulsion is reduced.
When we digest and metabolize fuels, the energy released is captured primarily in the
form of ATP.
ATP has two high-energy, ester bonds.
While ATP is the main energy currency of the cell, the three other nucleoside
triphosphates (GTP, UTP, CTP) are sometimes used to provide ener - Correct Answers
-ATP has two high-energy, ester bonds
Consider the following reaction:
Which of the following statements about this reaction is INCORRECT?
Correct!
This is a redox reaction in which glutamate is reduced to α-ketoglutarate.
The electrons that are lost in this reaction are captured in the form of NADH.
NAD+ is an oxidizing agent in this reaction.
While no ATP is directly formed in this reaction, ATP will be produced when NADH
donates its electrons in a process known as oxidative phosphorylation. - Correct
Answers -This is a redox reaction in which glutamate is reduced to α-ketoglutarate.
Which of the following molecules is an activated carrier of electrons used in many
biosynthetic reactions?
Coenzyme A
NADPH
NADH
FADH2 - Correct Answers -NADPH
Which of the following completes this sentence accurately?
Many activated carriers:
participate in isomerase reactions.
are small inorganic molecules that function as coenzymes.
are derived from B vitamins.
are derived from vitamin C. - Correct Answers -Are derived from B vitamins
From a metabolic perspective, why is high-fructose corn syrup, which is used widely in
the food industry, a concern?
Fructose is quickly phosphorylated to fructose-6-P, which leads to too much flux
through glycolysis and ends up causing too much fat synthesis.
Since there is no enzyme that can phosphorylate fructose, it can't be metabolized by
glycolysis, but is rather stored as sucrose which is toxic.
, Fructose is rapidly metabolized by the liver in an unregulated fashion through to
pyruvate. Some of the pyruvate is converted to ethanol.
Correct!
Fructose is metabolized in a way that bypasses the main regulatory point in glycolysis.
This leads to excess flow through glycolysis, and ultimately too much fat synthesis. -
Correct Answers -Fructose is metabolized in a way that bypasses the main regulatory
point in glycolysis. This leads to excess flow through glycolysis, and ultimately too much
fat synthesis.
What is the net number of ATP molecules produced for every one molecule of glucose
metabolized through glycolysis?
2
3
4
1 - Correct Answers -2
The conversation of pyruvate to this biomolecule produces the most energy:
Lactate
Acetyl CoA
Ethanol
Phosphoenolpyruvate - Correct Answers -Acetyl CoA
Which statement about lactose metabolism is CORRECT?
Lactose intolerance results from an enzyme deficiency that prevents galactose from
being converted to a glycolytic intermediate.
Correct!
The galactose that is produced from lactose degradation is metabolized through
several reactions to glucose-6-P.
Galactose is phosphorylated to galactose-6-P which is then converted to glucose-6-P
by an epimerase enzyme which changes the position of an hydroxyl group.
The conversation of pyruvate to lactate occurs mainly under aerobic conditions. -
Correct Answers -The galactose that is produced from lactose degradation is
metabolized through several reactions to glucose-6-P.
Which of the following statements about glycolysis is CORRECT?
The overall free energy change for the pathway is highly positive and thus only flows in
one direction, towards the production of pyruvate.
Since there are two steps in the pathway where ATP are consumed and four steps
where it is produced, the net production of ATP is two per glucose molecule.
Correct!
Some individual reactions in the pathway are reversible.
The phosphorylation of glucose to glucose-6-P is an example of substrate-level
phosphorylation. - Correct Answers -Some individual reactions in the pathway are
reversible.
