Question 1

In the glycogenesis pathway,the role of the glucose-6-phosphate isomerization reaction is to

Accepted Answer

A)  create a more stable intermediate for the subsequent reaction. 
B)  decrease the concentration of glucose-6-phosphate, thereby driving the pathway forward. 
C)  ensure that the charged molecule stays in the cell. 
D)  prepare the anomeric carbon for nucleophilic attack. 
A)  create a more stable intermediate for the subsequent reaction. 
B)  decrease the concentration of glucose-6-phosphate, thereby driving the pathway forward. 
C)  ensure that the charged molecule stays in the cell. 
D)  prepare the anomeric carbon for nucleophilic attack.

Question 2

What is the overall net reaction of the pentose phosphate pathway,where glucose-6-phosphate is entirely converted to CO2? Please include any cofactors produced for the cell.

Accepted Answer

glucose-6-phosphate

Question 3

The pentose phosphate pathway

Accepted Answer

A)  can be used to make seduheptulose-7-phosphate for use in RNA and DNA synthesis. 
B)  is linked at its start and at its end to the glycolysis pathway. 
C)  converges glycolysis intermediates with TCA cycle intermediates. 
D)  occurs in the mitochondrial matrix of cells. 
A)  can be used to make seduheptulose-7-phosphate for use in RNA and DNA synthesis. 
B)  is linked at its start and at its end to the glycolysis pathway. 
C)  converges glycolysis intermediates with TCA cycle intermediates. 
D)  occurs in the mitochondrial matrix of cells.

Question 4

During vigorous exercise the lactate produced in the muscle travels to the liver for recycling.Explain why starting with lactate is beneficial for the liver gluconeogenesis pathway.

Accepted Answer

Lactate in the liver (1)can be converted

Question 5

The hormone insulin activates phosphofructokinase 2 (2PFK2).This leads to a(n)__________ in concentration of fructose 2,6 bisphosphate,which favors the __________ pathway.

Accepted Answer

A)  increase; glycolysis 
B)  increase; gluconeogenesis 
C)  decrease; glycolysis 
D)  decrease; gluconeogenesis 
A)  increase; glycolysis 
B)  increase; gluconeogenesis 
C)  decrease; glycolysis 
D)  decrease; gluconeogenesis

Question 6

How many moles of NADH are required in gluconeogenesis to convert 2 moles of pyruvate molecules into 1 mole of glucose?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  4 
A)  0 
B)  1 
C)  2 
D)  4

Question 7

What molecules are missing from boxes in the gluconeogenesis reaction shown below?

Accepted Answer

A)  Ser-Pi; Ser-Pi 
B)  H2O; Pi 
C)  ADP; ATP 
D)  ATP; ADP 
A)  Ser-Pi; Ser-Pi 
B)  H2O; Pi 
C)  ADP; ATP 
D)  ATP; ADP

Question 8

The pentose phosphate pathway occurs in the

Accepted Answer

A)  cytoplasm. 
B)  nucleus. 
C)  Golgi apparatus. 
D)  mitochondria. 
A)  cytoplasm. 
B)  nucleus. 
C)  Golgi apparatus. 
D)  mitochondria.

Question 9

Draw a diagram indicating the organs,metabolic pathways,and key molecules involved in the circular Cori cycle.

Accepted Answer

The answer of Draw a diagram indicating the organs,metabolic pathways,and...

Question 10

In the elongation of glycogen,activated glucose units are attached to which hydroxyl of the terminal residue of the growing glycogen chain?

Accepted Answer

A)  C-1 
B)  C-3 
C)  C-4 
D)  C-6 
A)  C-1 
B)  C-3 
C)  C-4 
D)  C-6

Question 11

Of the four molecules listed below,three of them reciprocally regulate phosphofructokinase 1 (PFK1)and fructose-1,6-bisphosphatase.Which molecule does NOT fit?

Accepted Answer

A)  pyruvate 
B)  fructose-2,6-bisphosphate 
C)  citrate 
D)  AMP 
A)  pyruvate 
B)  fructose-2,6-bisphosphate 
C)  citrate 
D)  AMP

Question 12

In the reaction catalyzed by pyruvate carboxylase (the first reaction in gluconeogenesis),CO2 is

Accepted Answer

A)  lost from oxaloacetate. 
B)  activated by ATP energy. 
C)  activated by the cofactor NADH. 
D)  added to the phosphoenolpyruvate product. 
A)  lost from oxaloacetate. 
B)  activated by ATP energy. 
C)  activated by the cofactor NADH. 
D)  added to the phosphoenolpyruvate product.

Question 13

The products of the oxidative portion of the pentose phosphate pathway are carbon dioxide and

Accepted Answer

A)  2 NADH + 1 hexose phosphate. 
B)  2 NADP+ + 1 pentose phosphate. 
C)  2 NADPH + 1 hexose phosphate. 
D)  2 NADPH + 1 pentose phosphate. 
A)  2 NADH + 1 hexose phosphate. 
B)  2 NADP+ + 1 pentose phosphate. 
C)  2 NADPH + 1 hexose phosphate. 
D)  2 NADPH + 1 pentose phosphate.

Question 14

Name the four enzymes of the gluconeogenesis pathway that are NOT found in the glycolysis pathway.

Accepted Answer

Pyruvate carboxylase,phosphoen

Question 15

In the breakdown of glycogen,the debranching enzyme catalyzes the formation of

Accepted Answer

A)  glucose-1-phosphate. 
B)  glucose. 
C)    (1,6) branched glycogen. 
D)  glucose-6-phosphate. 
A)  glucose-1-phosphate. 
B)  glucose. 
C)    (1,6) branched glycogen. 
D)  glucose-6-phosphate.

Question 16

Explain how the Cori cycle leads to the regeneration of NAD+ for muscles with an active glycolysis pathway.

Accepted Answer

After glycolysis and the formation of py

Question 17

What would happen to cellular glucose-6-phosphate if the pentose phosphate pathway is inhibited?

Accepted Answer

The glucose-6-phosphate could

Question 18

Which statement of the debranching enzyme is true?

Accepted Answer

A)  It catalyzes the addition of free glucose to a nonreducing end of glycogen. 
B)  Its product is glucose-1-phosphate. 
C)  It evenly distributes branch points across the glycogen polymer. 
D)  It is one enzyme with three unique catalytic activities. 
A)  It catalyzes the addition of free glucose to a nonreducing end of glycogen. 
B)  Its product is glucose-1-phosphate. 
C)  It evenly distributes branch points across the glycogen polymer. 
D)  It is one enzyme with three unique catalytic activities.

Question 19

Which molecule allosterically activates pyruvate carboxylase?

Accepted Answer

A)  AMP 
B)  NAD+ 
C)  epinephrine 
D)  acetyl-CoA 
A)  AMP 
B)  NAD+ 
C)  epinephrine 
D)  acetyl-CoA

Question 20

In the glycogenesis pathway,which enzyme catalyzes the formation of   (1,6)linkages?

Accepted Answer

A)  debranching enzyme 
B)  glycogen synthase 
C)  glycogen phosphorylase 
D)  branching enzyme 
A)  debranching enzyme 
B)  glycogen synthase 
C)  glycogen phosphorylase 
D)  branching enzyme

Exam 14: Carbohydrate Metabolism

In the glycogenesis pathway,the role of the glucose-6-phosphate isomerization reaction is to

What is the overall net reaction of the pentose phosphate pathway,where glucose-6-phosphate is entirely converted to CO2? Please include any cofactors produced for the cell.

The pentose phosphate pathway

During vigorous exercise the lactate produced in the muscle travels to the liver for recycling.Explain why starting with lactate is beneficial for the liver gluconeogenesis pathway.

The hormone insulin activates phosphofructokinase 2 (2PFK2).This leads to a(n)__________ in concentration of fructose 2,6 bisphosphate,which favors the __________ pathway.

How many moles of NADH are required in gluconeogenesis to convert 2 moles of pyruvate molecules into 1 mole of glucose?

What molecules are missing from boxes in the gluconeogenesis reaction shown below?

The pentose phosphate pathway occurs in the

Draw a diagram indicating the organs,metabolic pathways,and key molecules involved in the circular Cori cycle.

In the elongation of glycogen,activated glucose units are attached to which hydroxyl of the terminal residue of the growing glycogen chain?

Of the four molecules listed below,three of them reciprocally regulate phosphofructokinase 1 (PFK1)and fructose-1,6-bisphosphatase.Which molecule does NOT fit?

In the reaction catalyzed by pyruvate carboxylase (the first reaction in gluconeogenesis),CO2 is

The products of the oxidative portion of the pentose phosphate pathway are carbon dioxide and

Name the four enzymes of the gluconeogenesis pathway that are NOT found in the glycolysis pathway.

In the breakdown of glycogen,the debranching enzyme catalyzes the formation of

Explain how the Cori cycle leads to the regeneration of NAD+ for muscles with an active glycolysis pathway.

What would happen to cellular glucose-6-phosphate if the pentose phosphate pathway is inhibited?

Which statement of the debranching enzyme is true?

Which molecule allosterically activates pyruvate carboxylase?

In the glycogenesis pathway,which enzyme catalyzes the formation of (1,6)linkages?

Principles of Biochemistry

Physical Biochemistry: Energy Conversion,water,and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Lipid Structure and Function

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Metabolic Integration

Dna Replication, repair, and Recombination

Rna Synthesis, processing, and Gene Silencing

Protein Synthesis, posttranslational Modification, and Transport

Gene Regulation

Filters

What is the overall net reaction of the pentose phosphate pathway,where glucose-6-phosphate is entirely converted to CO₂? Please include any cofactors produced for the cell.

The hormone insulin activates phosphofructokinase 2 (2PFK2).This leads to a(n) in concentration of fructose 2,6 bisphosphate,which favors the pathway.

In the reaction catalyzed by pyruvate carboxylase (the first reaction in gluconeogenesis),CO₂ is

Explain how the Cori cycle leads to the regeneration of NAD⁺ for muscles with an active glycolysis pathway.