Question 1

Where is the enzyme glucose-6-phosphatase located?

Accepted Answer

A)  cytosol 
B)  mitochondria 
C)  endoplasmic reticulum 
D)  nucleus 
E)  none of these 
A)  cytosol 
B)  mitochondria 
C)  endoplasmic reticulum 
D)  nucleus 
E)  none of these C

Question 2

The enzyme glycogen phosphorylase catalyzes a reaction in

Accepted Answer

A)  the formation of glycogen from glucose. 
B)  glycogen breakdown. 
C)  gluconeogenesis. 
D)  the pentose phosphate pathway. 
E)  glycolysis 
A)  the formation of glycogen from glucose. 
B)  glycogen breakdown. 
C)  gluconeogenesis. 
D)  the pentose phosphate pathway. 
E)  glycolysis B

Question 3

The compound uridine diphosphate glucose (UDPG) plays a role in

Accepted Answer

A)  glycogen breakdown. 
B)  glycogen synthesis. 
C)  glycolysis. 
D)  gluconeogenesis. 
E)  none of these 
A)  glycogen breakdown. 
B)  glycogen synthesis. 
C)  glycolysis. 
D)  gluconeogenesis. 
E)  none of these B

Question 4

Properly used, glycogen loading by athletes is a safe process.

Accepted Answer

A) True 
 B)False

Question 5

Which of the following happens when epinephrine and glucagon are released

Accepted Answer

A)  glycogen phosophorylase is activated and glycogen synthase is inhibited 
B)  glycogen phosphorylase and glycogen synthase are activated 
C)  glycogen phosphorylase and glycogen synthase are inhibited 
D)  glycogen phosphorylase is inhibited and glycogen synthase is activated 
E)  none of these 
A)  glycogen phosophorylase is activated and glycogen synthase is inhibited 
B)  glycogen phosphorylase and glycogen synthase are activated 
C)  glycogen phosphorylase and glycogen synthase are inhibited 
D)  glycogen phosphorylase is inhibited and glycogen synthase is activated 
E)  none of these

Question 6

The molecule fructose 2,6-bisphosphate:

Accepted Answer

A)  is an intermediate in glycolysis 
B)  is an intermediate of gluconeogenesis but not glycolysis 
C)  does not exist 
D)  is an important regulatory molecule in the control of carbohydrate metabolism 
E)  none of these 
A)  is an intermediate in glycolysis 
B)  is an intermediate of gluconeogenesis but not glycolysis 
C)  does not exist 
D)  is an important regulatory molecule in the control of carbohydrate metabolism 
E)  none of these

Question 7

In general, opposing pathways, such as glycolysis and gluconeogenesis are not exact reversals of each other.

Accepted Answer

A) True 
 B)False

Question 8

The NADH used for the reduction reactions during gluconeogenesis usually come from this reaction:

Accepted Answer

A)  Gylceraldehyde-3-phosphate dehydrogenase. 
B)  Malate dehydrogenase activity in the cytoplasm. 
C)  Pyruvate carboxylase activity in the mitochondria. 
D)  A variety of reactions which produce NADH in the mitochondria. 
E)  None of these, since it is NAD+ that is used in gluconeogenesis. 
A)  Gylceraldehyde-3-phosphate dehydrogenase. 
B)  Malate dehydrogenase activity in the cytoplasm. 
C)  Pyruvate carboxylase activity in the mitochondria. 
D)  A variety of reactions which produce NADH in the mitochondria. 
E)  None of these, since it is NAD+ that is used in gluconeogenesis.

Question 9

The vitamin thiamine is important in transferring all of these types of groups, except :

Accepted Answer

A)  2-carbon sugar fragments 
B)  3-carbon sugar fragments 
C)  4-carbon sugar fragments 
D)  Sugar fragments which contain a carbonyl group (C=O). 
E)  Thiamine can transfer all of these types of groups. 
A)  2-carbon sugar fragments 
B)  3-carbon sugar fragments 
C)  4-carbon sugar fragments 
D)  Sugar fragments which contain a carbonyl group (C=O). 
E)  Thiamine can transfer all of these types of groups.

Question 10

High concentrations of fructose-2,6- bis phopshate

Accepted Answer

A)  stimulate glycolysis and inhibit gluconeogenesis. 
B)  inhibit glycolysis and stimulate gluconeogenesis. 
C)  stimulate both glycolysis and gluconeogenesis. 
D)  inhibit both glycolysis and gluconeogenesis. 
E)  none of these 
A)  stimulate glycolysis and inhibit gluconeogenesis. 
B)  inhibit glycolysis and stimulate gluconeogenesis. 
C)  stimulate both glycolysis and gluconeogenesis. 
D)  inhibit both glycolysis and gluconeogenesis. 
E)  none of these

Question 11

Which of the following molecules does not directly regulate the activity of glycogen synthase?

Accepted Answer

A)  Glucose 
B)  Glucose-6-phosphate 
C)  AMP 
D)  ATP 
E)  Concentration of all of these affects glycogen synthase. 
A)  Glucose 
B)  Glucose-6-phosphate 
C)  AMP 
D)  ATP 
E)  Concentration of all of these affects glycogen synthase.

Question 12

It is impossible to reverse any kinase reaction under physiological conditions.

Accepted Answer

A) True 
 B)False

Question 13

How are the branches in glycogen produced?

Accepted Answer

A)  A branching enzyme catalyses the addition of a single glucose unit via an α (1,6) bond to glycogen from a glucose-1-phosphate, releasing Pi. 
B)  A branching enzyme catalyses the addition of a single glucose unit via an α (1,6) bond to glycogen from a glucose-6-phosphate, releasing Pi. 
C)  A branching enzyme catalyses the addition of a single glucose unit via an α (1,6) bond to glycogen from a glucose-UDP, releasing UDP. 
D)  A branching enzyme moves a short chain of several glucose units from a linear α (1,4) section of glycogen to make a new α (1,6) branch point. 
A)  A branching enzyme catalyses the addition of a single glucose unit via an α (1,6) bond to glycogen from a glucose-1-phosphate, releasing Pi. 
B)  A branching enzyme catalyses the addition of a single glucose unit via an α (1,6) bond to glycogen from a glucose-6-phosphate, releasing Pi. 
C)  A branching enzyme catalyses the addition of a single glucose unit via an α (1,6) bond to glycogen from a glucose-UDP, releasing UDP. 
D)  A branching enzyme moves a short chain of several glucose units from a linear α (1,4) section of glycogen to make a new α (1,6) branch point.

Question 14

​ Which of the following hormones is responsible for initiating the "fight or flight" response on a very short time scale?

Accepted Answer

A)  Galanin 
B)  Erythropoietin 
C)  Glucagon 
D)  Epinephrine 
A)  Galanin 
B)  Erythropoietin 
C)  Glucagon 
D)  Epinephrine

Question 15

The process called substrate cycling is used to describe this process:

Accepted Answer

A)  Freely reversible reactions. 
B)  Recycling of vitamins as catalysts in metabolism 
C)  Situations where there are two different enzymes used to reverse a specific step in a metabolic pathway. 
D)  Metabolic pathways which run in cycles and regenerate the initial molecule. 
E)  None of these answers describes substrate cycling. 
A)  Freely reversible reactions. 
B)  Recycling of vitamins as catalysts in metabolism 
C)  Situations where there are two different enzymes used to reverse a specific step in a metabolic pathway. 
D)  Metabolic pathways which run in cycles and regenerate the initial molecule. 
E)  None of these answers describes substrate cycling.

Question 16

Which of the following best describes the function of debranching enzyme?

Accepted Answer

A)  It simply cleaves α (1 → 6) bonds in glycogen via phosphorolysis. 
B)  It transfers a set of three glucose residues from a limit branch and then cleaves the α (1 → 6) bond via phosphorylsis. 
C)  It simply cleaves α (1 → 6) bonds in glycogen via hydrolysis. 
D)  It transfers a set of three glucose residues from a limit branch and then cleaves the α (1 → 6) bond via hydrolysis. 
E)  none of these describes the enzyme's function 
A)  It simply cleaves α (1 → 6) bonds in glycogen via phosphorolysis. 
B)  It transfers a set of three glucose residues from a limit branch and then cleaves the α (1 → 6) bond via phosphorylsis. 
C)  It simply cleaves α (1 → 6) bonds in glycogen via hydrolysis. 
D)  It transfers a set of three glucose residues from a limit branch and then cleaves the α (1 → 6) bond via hydrolysis. 
E)  none of these describes the enzyme's function

Question 17

Glucose-6-phosphatase activity is found associated with the endoplasmic reticulum.

Accepted Answer

A) True 
 B)False

Question 18

Gluconeogenesis is the synthesis of

Accepted Answer

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

Question 19

The formation and breakdown of fructose 2,6- bis phosphate

Accepted Answer

A)  is catalyzed by the same protein dependant upon whether it is phosphorylated or not. 
B)  is catalyzed by the same protein dependant allosteric regulators. 
C)  is catalyzed by different proteins. 
D)  none of these 
A)  is catalyzed by the same protein dependant upon whether it is phosphorylated or not. 
B)  is catalyzed by the same protein dependant allosteric regulators. 
C)  is catalyzed by different proteins. 
D)  none of these

Question 20

Which of the following molecules is not a product of the pentose phosphate pathway?

Accepted Answer

A)  NADPH 
B)  ribose-5-phosphate 
C)  glycerate-3-phosphate 
D)  xylulose-5-phosphate 
A)  NADPH 
B)  ribose-5-phosphate 
C)  glycerate-3-phosphate 
D)  xylulose-5-phosphate

Exam 18: Storage Mechanisms and Control in Carbohydrate Metabolism

Where is the enzyme glucose-6-phosphatase located?

The enzyme glycogen phosphorylase catalyzes a reaction in

The compound uridine diphosphate glucose (UDPG) plays a role in

Properly used, glycogen loading by athletes is a safe process.

Which of the following happens when epinephrine and glucagon are released

The molecule fructose 2,6-bisphosphate:

In general, opposing pathways, such as glycolysis and gluconeogenesis are not exact reversals of each other.

The NADH used for the reduction reactions during gluconeogenesis usually come from this reaction:

The vitamin thiamine is important in transferring all of these types of groups, except :

High concentrations of fructose-2,6- bis phopshate

Which of the following molecules does not directly regulate the activity of glycogen synthase?

It is impossible to reverse any kinase reaction under physiological conditions.

How are the branches in glycogen produced?

​ Which of the following hormones is responsible for initiating the "fight or flight" response on a very short time scale?

The process called substrate cycling is used to describe this process:

Which of the following best describes the function of debranching enzyme?

Glucose-6-phosphatase activity is found associated with the endoplasmic reticulum.

Gluconeogenesis is the synthesis of

The formation and breakdown of fructose 2,6- bis phosphate

Which of the following molecules is not a product of the pentose phosphate pathway?

Biochemistry and the Organization of Cells

Water the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins Enzymes

The Behavior of Proteins Enzymes Mechanisms and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids How Structure Conveys Information

Biosynthesis of Nucleic Acids Replication

Transcription of the Genetic Code the Biosynthesis of Rna

Protein Synthesis Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses Cancer and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism Cellular Signaling

Filters

Which of the following hormones is responsible for initiating the "fight or flight" response on a very short time scale?