Question 1

What is the primary regulatory point of gluconeogenesis?

Accepted Answer

A) glucose-6-phosphatase 
B) fructose-1,6-bisphosphatase 
C) fructose-2,6-bisphosphatase 
D) pyruvate carboxylase 
E) PEP carboxykinase 
A) glucose-6-phosphatase 
B) fructose-1,6-bisphosphatase 
C) fructose-2,6-bisphosphatase 
D) pyruvate carboxylase 
E) PEP carboxykinase

Question 2

Which major tissues carry out gluconeogenesis?

Accepted Answer

A) brain and muscles 
B) muscles and kidneys 
C) liver and kidneys 
D) red blood cells and brain 
A) brain and muscles 
B) muscles and kidneys 
C) liver and kidneys 
D) red blood cells and brain

Question 3

Which of the following is NOT a physiological effect of insulin?

Accepted Answer

A) inhibition of glycogen phosphorylase 
B) inducement of synthesis of glucokinase,PFK-1,and pyruvate kinase 
C) stimulation of active transport of glucose and amino acids into muscle and adipose tissues 
D) stimulation of fructose-1,6-bisphosphatase 
A) inhibition of glycogen phosphorylase 
B) inducement of synthesis of glucokinase,PFK-1,and pyruvate kinase 
C) stimulation of active transport of glucose and amino acids into muscle and adipose tissues 
D) stimulation of fructose-1,6-bisphosphatase

Question 4

What is synthesized in gluconeogenesis?

Accepted Answer

A) glucose from non-carbohydrate precursors 
B) glycogen from glucose 
C) pyruvate from glucose 
D) fatty acids from glucose 
A) glucose from non-carbohydrate precursors 
B) glycogen from glucose 
C) pyruvate from glucose 
D) fatty acids from glucose

Question 5

Glucose monitoring devices use the reaction,glucose + O₂ + 2 H₂O → gluconate + 2 H₂O₂.Which enzyme catalyzes this reaction?

Accepted Answer

A) gluconate synthase 
B) glucose oxidase. 
C) peroxidase 
D) glucose oxidase 
A) gluconate synthase 
B) glucose oxidase. 
C) peroxidase 
D) glucose oxidase

Question 6

Which enzyme catalyzes bicarbonate "activation" by attachment to the g-phosphate of ATP to form carbonyl phosphate?

Accepted Answer

A) glucokinase 
B) glucose-6-phosphatase 
C) PEP carboxykinase 
D) pyruvate carboxylase 
A) glucokinase 
B) glucose-6-phosphatase 
C) PEP carboxykinase 
D) pyruvate carboxylase

Question 7

Which process describes the 6-phosphogluconate dehydrogenase reaction?

Accepted Answer

A) substrate-level phosphorylation 
B) oxidative decarboxylation 
C) TPP-assisted decarboxylation 
D) phosphate addition 
A) substrate-level phosphorylation 
B) oxidative decarboxylation 
C) TPP-assisted decarboxylation 
D) phosphate addition

Question 8

The ratio of NADP⁺/NADPH in liver runs about 1/67.What does this mean?

Accepted Answer

A) Glucose-6-phosphate dehydrogenase activity is dependent upon use of some of the NADPH before activity increases. 
B) Glucose-6-phosphate dehydrogenase will be turned on most of the time. 
C) Glucose-6-phosphate is rate limiting for the pentose phosphate pathway. 
D) Glucose-6-phosphate goes preferentially to the pentose phosphate pathway. 
A) Glucose-6-phosphate dehydrogenase activity is dependent upon use of some of the NADPH before activity increases. 
B) Glucose-6-phosphate dehydrogenase will be turned on most of the time. 
C) Glucose-6-phosphate is rate limiting for the pentose phosphate pathway. 
D) Glucose-6-phosphate goes preferentially to the pentose phosphate pathway.

Question 9

Epinephrine elicits many physiological changes such as the initiation of the adenylyl cyclase cascade.Which of these actions is NOT seen as a result of this initiation?

Accepted Answer

A) stimulation of glycogen synthase 
B) activation of glycogenolysis in liver 
C) stimulation of glycolysis by 2000-fold 
D) activation of glycogenolysis in muscles 
A) stimulation of glycogen synthase 
B) activation of glycogenolysis in liver 
C) stimulation of glycolysis by 2000-fold 
D) activation of glycogenolysis in muscles

Question 10

Which of the following is NOT an enzyme in the enzyme cascade for activation of glycogen phosphorylase?

Accepted Answer

A) adenylyl cyclase 
B) protein kinase A 
C) hormone-sensitive lipase 
D) phosphorylase kinase 
A) adenylyl cyclase 
B) protein kinase A 
C) hormone-sensitive lipase 
D) phosphorylase kinase

Question 11

What does the enzyme transketolase catalyze?

Accepted Answer

A) transfers of 3-carbon units from a ketose to an aldose 
B) transfer of ketoses into aldoses 
C) TPP-dependent transfer of 2-carbon units to the recipient aldose 
D) keto-group transfer from C-2 to C-3 
A) transfers of 3-carbon units from a ketose to an aldose 
B) transfer of ketoses into aldoses 
C) TPP-dependent transfer of 2-carbon units to the recipient aldose 
D) keto-group transfer from C-2 to C-3

Question 12

Which of these reactions represents the gluconeogenic reversal of PFK-1 in glycolysis?

Accepted Answer

A) fructose-6-P + ADP→ fructose + ATP 
B) fructose-6-P + H₂O →fructose + Pi 
C) fructose-1,6-bisphosphate + ADP →fructose-6-P + ATP 
D) fructose-1,6-bisphosphate + H₂O →fructose-6-P + Pi 
A) fructose-6-P + ADP→ fructose + ATP 
B) fructose-6-P + H₂O →fructose + Pi 
C) fructose-1,6-bisphosphate + ADP →fructose-6-P + ATP 
D) fructose-1,6-bisphosphate + H₂O →fructose-6-P + Pi

Question 13

Which enzyme-catalyzed reaction is analogous to the phosphopentose isomerase reaction and mechanism?

Accepted Answer

A) UDP-glucose epimerase 
B) phosphoglycerate isomerase 
C) phosphopentose epimerase 
D) phosphoglucoisomerase 
A) UDP-glucose epimerase 
B) phosphoglycerate isomerase 
C) phosphopentose epimerase 
D) phosphoglucoisomerase

Question 14

The polyol pathway is a suspected pathway for diabetes-induced cataract formation.Which enzyme does it involve?

Accepted Answer

A) aldose reductase 
B) glucose-6-phosphate dehydrogenase 
C) phosphopentose isomerase 
D) transaldolase 
A) aldose reductase 
B) glucose-6-phosphate dehydrogenase 
C) phosphopentose isomerase 
D) transaldolase

Question 15

Glucose-6-phosphatase is located in the endoplasmic reticulum.What does the enzyme produce in vesicles that diffuse to the plasma membrane,releasing their contents into the blood stream?

Accepted Answer

A) lactate 
B) glucose-6-phosphate 
C) sucrose 
D) glucose 
A) lactate 
B) glucose-6-phosphate 
C) sucrose 
D) glucose

Question 16

Insulin in the bloodstream is a response to increased blood glucose.What does insulin do as a result of this?

Accepted Answer

A) stimulates gluconeogenesis 
B) inhibits glycolysis 
C) stimulates glycogen synthesis in muscle and liver 
D) inhibits phosphoprotein phosphatase-1 
A) stimulates gluconeogenesis 
B) inhibits glycolysis 
C) stimulates glycogen synthesis in muscle and liver 
D) inhibits phosphoprotein phosphatase-1

Question 17

Which of the following is NOT correct for a-amylase?

Accepted Answer

A) Its activity is reduced in highly branched regions of polysaccharides and stops 4 residues from any branch point. 
B) It is an important component of saliva and pancreatic juice. 
C) It catalyzes hydrolysis of ? (1?6)linkages in amylopectin. 
D) It catalyzes hydrolysis of ? (1?4)linkages in glycogen. 
A) Its activity is reduced in highly branched regions of polysaccharides and stops 4 residues from any branch point. 
B) It is an important component of saliva and pancreatic juice. 
C) It catalyzes hydrolysis of ? (1?6)linkages in amylopectin. 
D) It catalyzes hydrolysis of ? (1?4)linkages in glycogen.

Question 18

Which of these reactions is catalyzed by a transketolase in the pentose phosphate pathway?

Accepted Answer

A) erythrose-4-P + fructose-6-P ↔sedoheptulose-7-P + glyceraldehyde-3-P 
B) sedoheptulose-7-P + glyceraldehyde-3-P ↔ erythrose-4-P + fructose-6-P 
C) fructose-6-P + glyceraldehyde-3-P ↔ xylulose-5-P + erythrose-4-P 
D) glucose-6-P +2 NADP+ + H₂0 ↔ ribose-5-P +2 NADPH +2 H⁺ 
A) erythrose-4-P + fructose-6-P ↔sedoheptulose-7-P + glyceraldehyde-3-P 
B) sedoheptulose-7-P + glyceraldehyde-3-P ↔ erythrose-4-P + fructose-6-P 
C) fructose-6-P + glyceraldehyde-3-P ↔ xylulose-5-P + erythrose-4-P 
D) glucose-6-P +2 NADP+ + H₂0 ↔ ribose-5-P +2 NADPH +2 H⁺

Question 19

In the Cori cycle,the liver shares the load of exercising muscle.What is this a result of?

Accepted Answer

A) high acetate levels 
B) high galactose levels 
C) a high NAD⁺/NADH ratio 
D) a high FAD/FADH ratio 
A) high acetate levels 
B) high galactose levels 
C) a high NAD⁺/NADH ratio 
D) a high FAD/FADH ratio

Question 20

Which of the following enzymes is NOT unique to gluconeogenesis?

Accepted Answer

A) phosphoglucoisomerase 
B) glucose-6-phosphatase 
C) fructose-1,6-bisphosphatase 
D) PEP carboxykinase 
A) phosphoglucoisomerase 
B) glucose-6-phosphatase 
C) fructose-1,6-bisphosphatase 
D) PEP carboxykinase

Exam 21: Gluconeogenesis, glycogen Metabolism, and the Pentose Phosphate Pathway

What is the primary regulatory point of gluconeogenesis?

Which major tissues carry out gluconeogenesis?

Which of the following is NOT a physiological effect of insulin?

What is synthesized in gluconeogenesis?

Glucose monitoring devices use the reaction,glucose + O₂ + 2 H₂O → gluconate + 2 H₂O₂.Which enzyme catalyzes this reaction?

Which enzyme catalyzes bicarbonate "activation" by attachment to the g-phosphate of ATP to form carbonyl phosphate?

Which process describes the 6-phosphogluconate dehydrogenase reaction?

The ratio of NADP⁺/NADPH in liver runs about 1/67.What does this mean?

Epinephrine elicits many physiological changes such as the initiation of the adenylyl cyclase cascade.Which of these actions is NOT seen as a result of this initiation?

Which of the following is NOT an enzyme in the enzyme cascade for activation of glycogen phosphorylase?

What does the enzyme transketolase catalyze?

Which of these reactions represents the gluconeogenic reversal of PFK-1 in glycolysis?

Which enzyme-catalyzed reaction is analogous to the phosphopentose isomerase reaction and mechanism?

The polyol pathway is a suspected pathway for diabetes-induced cataract formation.Which enzyme does it involve?

Glucose-6-phosphatase is located in the endoplasmic reticulum.What does the enzyme produce in vesicles that diffuse to the plasma membrane,releasing their contents into the blood stream?

Insulin in the bloodstream is a response to increased blood glucose.What does insulin do as a result of this?

Which of the following is NOT correct for a-amylase?

Which of these reactions is catalyzed by a transketolase in the pentose phosphate pathway?

In the Cori cycle,the liver shares the load of exercising muscle.What is this a result of?

Which of the following enzymes is NOT unique to gluconeogenesis?

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Lipid Biosynthesis

Membranes and Membrane Transport

The Reception and Transmission of Extracellular Information

Enzymes Kinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Nutrition and the Organization of Metabolism

Glycolysis

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Fatty Acid Catabolism

Nitrogen Acquisition and Amino Acid Metabolism

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Synthesis and Degradation of Nucleotides

Recombinant Dna: Cloning and Creation of Chimeric Genes

DNA Metabolism: Replication, recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

Post-Transcriptional Regulation of Gene Expression

Completing the Protein Life Cycle: Folding, processing, and Degradation

Metabolic Integration and Organ Specialization

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