MMSC 491 Exam 2 Practice (A+ Guaranteed)
What is the purpose of phosphorylating glucose in cytosol? correct answers A and B
What reaction is catalyzed by aldolase? correct answers reversible cleavage of F-1,6-BP to DHAP and GAP
What are the primary metabolic fates of pyruvate? correct answers All of the above (ethanol, acetyl CoA, and lactate)
High levels of ATP and citrate correct answers All of the above (inhibit glycolysis, indicate remote gluconeogenesis, and indicate a high-energy well-fed state)
The major site for gluconeogenesis is in which of the following tissues? correct answers liver
In which step of the citric acid cycle is FADH2 formed? correct answers the conversion of succinate to fumerate
What is the function of a thioester intermediate such as the one formed from GAP? correct answers the thioester allows the two-step reaction to be coupled so the second reaction, the energetically unfavorable phosphorylation, can proceed
Which of the following does not participate in, nor is a component of, the electron-transport chain? correct answers coenzyme A
Which of the following does not pump protons? correct answers Complex II
The F1 component of ATP synthase is composed of correct answers All of the above (a gamma subunit, three beta and three alpha subunits)
The proton motive force consists of correct answers A and B
Suppose there is a mutation in the c subunit of ATP synthase, such that the glutamate found in the middle of one of the membrane spanning helices is converted to a valine. What is likely to be
the effect on ATP synthesis and why? correct answers inhibit ATP synthesis. Valine cannot bind a proton, so there will be no proton flow through the inner membrane
What two 3-carbon molecules are generated by the cleavage of fructose-1,6-bisphosphate? correct answers glyceraldehyde-3-phosphate and dihydroxyacetone phosphate
What is the function of glyceraldehyde 3-phosphate dehydrogenase? correct answers oxidation by NAD+ and formation of acyl-phosphate
What type of enzyme catalyzes the intramolecular shift of a chemical group? correct answers Mutase Fructose can enter glycolysis at two distinct points, depending on the tissue. How is fructose metabolized in adipose tissue? correct answers fructose is converted to fructose-6-phosphate
Lactose intolerance is caused by a deficiency of correct answers lactase
Cancer driven hypoxia brings about the induction of which genes involved in glycolysis? correct answers All of the above (hexokinase, GLUT3, aldolase)
During exercise, glycolysis is stimulated by a: correct answers feed-forward stimulation of pyruvate kinase
Phosphofructokinase (PFK) is a highly regulated enzyme. Which of the following statements about PFK are correct? correct answers None of the above
The bifunctional enzyme in glycolysis stage I is also known as correct answers phosphofructokinase II
High blood sugar after a meal ...... the level of insulin released by the pancreas correct answers increases
In general the liver...... correct answers all of the above (acts as a glucose buffer for the rest of the body, will not utilize glucose under starvation/low energy conditions, and is a producer of glucose for the body under low energy conditions
The direct movement of substrates from one enzyme to the next is called correct answers substrate channeling
What is (are) the chemical change(s) involved in the conversion of citrate into isocitrate? correct answers isomerization
Approximately how many ATP or GTP equivalents are produced during one turn of the citric acid cycle? correct answers 10
In addition to pyruvate dehydrogenase, what other enzymes are key regulatory sites in the citric acid cycle? correct answers A and B
Coenzyme Q is also called correct answers ubiquinone
When glucose is totally oxidized to CO2 and H2O, how many ATP molecules are made by oxidative phosphorylation relative to the maximum yield? correct answers 26 out of 30
Electron flow down the electron-transport chain leads to the correct answers transport of protons across the inner mitochondrial membrane from inside the matrix to the intermembrane space
How does the rotation of the c ring lead to ATP synthesis? correct answers The c ring is linked tightly to the gamma and epsilon subunits in the stalk of F1
What is the purpose of phosphorylating glucose in cytosol? correct answers A and B
What reaction is catalyzed by aldolase? correct answers reversible cleavage of F-1,6-BP to DHAP and GAP
What are the primary metabolic fates of pyruvate? correct answers All of the above (ethanol, acetyl CoA, and lactate)
High levels of ATP and citrate correct answers All of the above (inhibit glycolysis, indicate remote gluconeogenesis, and indicate a high-energy well-fed state)
The major site for gluconeogenesis is in which of the following tissues? correct answers liver
In which step of the citric acid cycle is FADH2 formed? correct answers the conversion of succinate to fumerate
What is the function of a thioester intermediate such as the one formed from GAP? correct answers the thioester allows the two-step reaction to be coupled so the second reaction, the energetically unfavorable phosphorylation, can proceed
Which of the following does not participate in, nor is a component of, the electron-transport chain? correct answers coenzyme A
Which of the following does not pump protons? correct answers Complex II
The F1 component of ATP synthase is composed of correct answers All of the above (a gamma subunit, three beta and three alpha subunits)
The proton motive force consists of correct answers A and B
Suppose there is a mutation in the c subunit of ATP synthase, such that the glutamate found in the middle of one of the membrane spanning helices is converted to a valine. What is likely to be
the effect on ATP synthesis and why? correct answers inhibit ATP synthesis. Valine cannot bind a proton, so there will be no proton flow through the inner membrane
What two 3-carbon molecules are generated by the cleavage of fructose-1,6-bisphosphate? correct answers glyceraldehyde-3-phosphate and dihydroxyacetone phosphate
What is the function of glyceraldehyde 3-phosphate dehydrogenase? correct answers oxidation by NAD+ and formation of acyl-phosphate
What type of enzyme catalyzes the intramolecular shift of a chemical group? correct answers Mutase Fructose can enter glycolysis at two distinct points, depending on the tissue. How is fructose metabolized in adipose tissue? correct answers fructose is converted to fructose-6-phosphate
Lactose intolerance is caused by a deficiency of correct answers lactase
Cancer driven hypoxia brings about the induction of which genes involved in glycolysis? correct answers All of the above (hexokinase, GLUT3, aldolase)
During exercise, glycolysis is stimulated by a: correct answers feed-forward stimulation of pyruvate kinase
Phosphofructokinase (PFK) is a highly regulated enzyme. Which of the following statements about PFK are correct? correct answers None of the above
The bifunctional enzyme in glycolysis stage I is also known as correct answers phosphofructokinase II
High blood sugar after a meal ...... the level of insulin released by the pancreas correct answers increases
In general the liver...... correct answers all of the above (acts as a glucose buffer for the rest of the body, will not utilize glucose under starvation/low energy conditions, and is a producer of glucose for the body under low energy conditions
The direct movement of substrates from one enzyme to the next is called correct answers substrate channeling
What is (are) the chemical change(s) involved in the conversion of citrate into isocitrate? correct answers isomerization
Approximately how many ATP or GTP equivalents are produced during one turn of the citric acid cycle? correct answers 10
In addition to pyruvate dehydrogenase, what other enzymes are key regulatory sites in the citric acid cycle? correct answers A and B
Coenzyme Q is also called correct answers ubiquinone
When glucose is totally oxidized to CO2 and H2O, how many ATP molecules are made by oxidative phosphorylation relative to the maximum yield? correct answers 26 out of 30
Electron flow down the electron-transport chain leads to the correct answers transport of protons across the inner mitochondrial membrane from inside the matrix to the intermembrane space
How does the rotation of the c ring lead to ATP synthesis? correct answers The c ring is linked tightly to the gamma and epsilon subunits in the stalk of F1
