BYS 301- Ch 8 Carbohydrate Metabolism

Aldol cleavage of which of the following sugars will produce one mole each of dihydroxyacetone and glyceraldehyde? A) Fructose B) Glucose C) Ribose D) Maltose E) Trehalose

A) Fructose

The conversion of glucose-1-phosphate to UDP-glucose has a delta G0' near zero. Which of the following reactions is coupled with the previous reaction to drive it to completion? A) Hydrolysis of PPi B) Hydrolysis of ATP C) Hydrolysis of ADP D) Hydrolysis of UDP E) Hydrolysis of UTP

A) Hydrolysis of PPi

Which of the following activates phosphoprotein phosphatase? A) Insulin B) Epinephrine C) Glucagon D) ATP E) Both A and B are correct

A) Insulin

Which of the following enzymes catalyzes an irreversible process? A) Pyruvate kinase B) Aldolase C) Enolase D) Phosphoglycerate mutase E) Glyceraldehyde-3-phosphate dehydrogenase

A) Pyruvate kinase

A diauxic shift is __________. A) a significant change in gene expression B) shifting from aerobic to anerobic respiration C) shifting from anerobic to aerobic respiration D) change in composition of microbes in a sample E) change in the amount of ATP used to ferment glucose

A) a significant change in gene expression

Phosphorylase kinase __________. A) converts inactive phosphorylase to active phosphorylase B) converts active phosphorylase to inactive phosphorylase C) phosphorylates glycogen synthase D) converts ADP to ATP E) Both B and C are correct.

A) converts inactive phosphorylase to active phosphorylase

Intermediates in the nonoxidative phase of the pentose phosphate pathway include all of the following except __________. A) dihydroxyacetone phosphate B) sedoheptulose-7-phosphate C) fructose-6-phosphate D) xylulose-5-phosphate E) erythrose-4-phosphate

A) dihydroxyacetone phosphate

The major carbohydrate fuel for most organisms is __________. A) glucose B) fructose C) ribose D) sucrose E) All of the above are correct.

A) glucose

Fructose-2,6-bisphosphate __________. A) is an indicator of high cellular glucose concentration B) is formed by PFK-1 C) activates aldolase D) Both A and B are correct. E) All of the above are correct.

A) is an indicator of high cellular glucose concentration

Which of the following is the most important glucogenic amino acid? A) Aspartate B) Alanine C) Glycine D) Glutamate E) All are equally important

B) Alanine

Which of the following compounds is an end product of an aerobic respiration? A) Carbon dioxide B) Ethanol C) Water D) Glycogen E) Acetaldehyde

B) Ethanol

Flux of which of the following sugars into the glycolytic pathway is essentially unregulated. A) Glucose B) Fructose C) Glucose-1-phosphate D) Both A and C are correct E) None of the above are correct

B) Fructose

The binding of insulin to receptors on the surface of muscle cells stimulates which of the following processes? A) Glycogenolysis B) Glycogenesis C) Release of ATP D) Formation of cyclic AMP E) Release of glucagon

B) Glycogenesis

Which of the following enzymes is not required in gluconeogenesis? A) Phosphoenolpyruvate carboxy kinase B) Phosphofructokinase C) Pyruvate kinase D) Fructose-1,6-bisphosphatase E) Pyruvate carboxylase

B) Phosphofructokinase

Both glycogenesis and glycogenolysis are controlled primarily by the interplay between the two hormones insulin and __________. A) glycogen synthetase B) glucagon C) fructose kinase D) glucose hydrolyase E) pentose kinase

B) glucagon

Hexokinase D is found in the __________ A)kidney B) liver C) heart D) muscle E) intestine

B) liver

The final product of glycolysis is __________. A) dihydroxyacetone phosphate B) pyruvate C) ethanol D) acetyl-CoA E) acetaldehyde

B) pyruvate

The Crabtree effect in yeast is __________. A) fermentation of glucose B) repression of aerobic metabolism by glucose C) repression of glycolysis by oxygen D) repression of glucose metabolism by ethyl alcohol E) fermentation of ethyl alcohol

B) repression of aerobic metabolism by glucose

The use of a highly exergonic reaction in the beginning of a catabolic pathway is referred to as __________. A) bioactivation B) turbo design C) activation D) glycolysis E) Both A and C are correct.

B) turbo design

In glycolysis __________ moles of ATP are produced per mole of glucose consumed. A) one B) two C) three D) four E) five

B) two

In glycolysis __________ moles of NADH are produced per mole of glucose consumed. A) one B) two C) three D) four E) five

B) two

Which of the following enzymes is an oxidoreductase? A) Aldolase B) Triose phosphate isomerase C) Glyceraldehyde-3-phosphate dehdyrogenase D) Phosphofructokinase E) Phosphoglucoisomerase

C) Glyceraldehyde-3-phosphate dehdyrogenase

In animals excess glucose is converted into its storage form,__________. A) starch B) chitin C) glycogen D) amylose E) amylopectin

C) glycogen

The Embden-Myerhof pathway is also referred to as __________. A) gluconeogenesis B) glycogenolysis C) glycolysis D) glycogenesis E) citric acid cycle

C) glycolysis

An enzyme family called the __________ catalyzes the phosphorylation of hexoses in the body. A) hexolysases B) phosphorolyases C) hexokinases D) glucokinases E) phosphofructokinases

C) hexokinases

Gluconeogenesis occurs primarily in the __________. A) brain B) muscle C) liver D) heart E) pancreas

C) liver

Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate has two purposes. One is the commitment of the molecule to glycolysis ;the second is __________. A) raising the free energy of the system B) making possible the formation of a second mole of ATP C) preventing the cleavage products of the next step from diffusing out of the cell D) preventing the reverse reaction E) enolization of the product

C) preventing the cleavage products of the next step from diffusing out of the cell

The Pasteur effect is __________. A) fermentation of glucose B) repression of aerobic metabolism by glucose C) repression of glycolysis by oxygen D) repression of glucose metabolism by ethyl alcohol E) fermentation of ethyl alcohol

C) repression of glycolysis by oxygen

In anaerobic organisms pyruvate is used to regenerate cellular __________. A) NADP+ B) FADH C) FAD D) NAD+ E) ADP

D) NAD+

Which of the following enzymes will catalyze the first committed step in glycolysis? A) Phosphofructoisomerase B) Aldolase C) Triose phosphate isomerase D) Phosphofructokinase 1 E) Phosphoglucooisomerase

D) Phosphofructokinase 1

Which of the following is an oxidizing agent in fermentation? A) Lactate B) Glucose C) NADH D) Pyruvate E) ADP

D) Pyruvate

In addition to glucose which of the following sugars are important in the human diet? A) Fructose B) Galactose C) Mannose D) Sucrose E) Both A and D are correct.

D) Sucrose

Cori's disease is caused by __________. A) lack of insulin B)lack of phosphorylase b C) lack of glucagons D) a deficiency of debranching enzyme E) deficient chromium receptors on the cell surface

D) a deficiency of debranching enzyme

The first reaction in the oxidative phase of the pentose phosphate pathway is catalyzed by __________. A) ribulose-5-phosphate dehydrogenase B) transketolase C) glucose-6-phosphatase D) glucose-6-phosphate dehydrogenase E) hexokinase

D) glucose-6-phosphate dehydrogenase

A glycogen molecule that has been degraded to its branch points is called __________. A) dextrin B) glucose C) amylose D) limit dextrin E) Both A and B are correct.

D) limit dextrin

Gluconeogenesis is stimulated by high concentrations of which of the following compounds? A) Lactate B) Glycerol C) Amino acid D) Both A and B are correct E) All of the above are correct

E) All of the above are correct

Allosteric regulation of which of the following enzymes is important in the regulation of glycolysis? A) Hexokinase B) PFK-1 C) Pyruvate kinase D) Both A and C are correct. E) All of the above are correct.

E) All of the above are correct.

Which of the following molecules can be used to synthesize glucose via gluconeogenesis? A) Lactate B) Pyruvate C) Glycerol D) Keto acids E) All of the above are correct.

E) All of the above are correct.

Under stressful conditions epinephrine is released from the adrenal medulla. The release of epinephrine has which of the following effects on glucose metabolism? A) Glycogenolysis is stimulated B) Glycogenesis is inhibited C) Adenylate cyclase is activated D) Both A and Bare correct. E) All the above are correct.

E) All the above are correct.

Glucose-6-phosphate is a substrate in which of the following processes? A) Gluconeogenesis B) Glycolysis C) Photosynthesis D) Glycogenolysis E) Both A and B are correct.

E) Both A and B are correct.

The presence of which of the following molecules indicates that the cell has sufficient energy reserves? A) ATP B) Citrate C) ADP D) Fructose-1,6-biphosphate E) Both A and B are correct.

E) Both A and B are correct.

Which of the following is required for the conversion of UDP- glucose to glycogen? A) Glycogen synthase B) Branching enzyme C) Glucose phosphorylase D) Debranching enzyme E) Both A and B are correct.

E) Both A and B are correct.

The phosphorylation of glucose when it enters a cell accomplishes which of the following ? A) Makes the glucose more water soluble B) Prevents back diffusion out of the cell C) Isomerize the glucose D) Activates the glucose for further reaction E) Both B and D are correct.

E) Both B and D are correct.

The principal products of the pentose phosphate pathway include __________. A) NADH B) NADPH C) ATP D) ribose-5-phosphate E) Both B and D are correct.

E) Both B and D are correct.

Regulation of glycolysis involves all of the following except __________. A) insulin B) glucagon C) SREBP1c D) AMPK E) None of the above are correct.

E) None of the above are correct.

Which of the following is a second messenger in glycogenolysis? A) Glucagon B) Insulin C) Glucose D) ATP E) cAMP

E) cAMP