Pentose Phosphate Pathway

Question 1

What is the primary function of the pentose phosphate pathway?

Answer 1

The primary function of the pentose phosphate pathway is to generate NADPH and ribose-5-phosphate for anabolic reactions.

Question 2

True or False: The pentose phosphate pathway occurs in the mitochondria.

Answer 2

False: The pentose phosphate pathway occurs in the cytoplasm.

Question 3

Fill in the blank: The pentose phosphate pathway consists of two phases: the _______ phase and the _______ phase.

Answer 3

oxidative; non-oxidative

Question 4

What is the main product of the oxidative phase of the pentose phosphate pathway?

Answer 4

NADPH and ribulose-5-phosphate.

Question 5

Which enzyme catalyzes the first step of the pentose phosphate pathway?

Answer 5

Glucose-6-phosphate dehydrogenase.

Question 6

Multiple Choice: Which of the following is NOT a product of the pentose phosphate pathway? A) NADPH B) ATP C) Ribose-5-phosphate D) CO2

Answer 6

B) ATP

Question 7

What role does NADPH play in cellular metabolism?

Answer 7

NADPH serves as a reducing agent in various biosynthetic reactions and helps in maintaining the cellular redox state.

Question 8

True or False: The non-oxidative phase of the pentose phosphate pathway can interconvert sugars.

Answer 8

True.

Question 9

What is ribose-5-phosphate used for in the cell?

Answer 9

Ribose-5-phosphate is used for the synthesis of nucleotides and nucleic acids.

Question 10

Fill in the blank: The pentose phosphate pathway provides reducing power for _______ synthesis.

Answer 10

fatty acid

Question 11

Which metabolite is produced during the decarboxylation step in the oxidative phase?

Answer 11

Ribulose-5-phosphate.

Question 12

What is the significance of the transketolase enzyme in the non-oxidative phase?

Answer 12

Transketolase catalyzes the transfer of two-carbon units between sugars.

Question 13

What is the end product of the non-oxidative phase of the pentose phosphate pathway?

Answer 13

Fructose-6-phosphate and glyceraldehyde-3-phosphate.

Question 14

True or False: The pentose phosphate pathway is essential for all types of cells.

Answer 14

True.

Question 15

What are the two main phases of the pentose phosphate pathway?

Answer 15

Oxidative phase and non-oxidative phase.

Question 16

Multiple Choice: Which of the following enzymes is involved in the oxidative phase? A) Aldolase B) Glucose-6-phosphate dehydrogenase C) Transaldolase D) Phosphofructokinase

Answer 16

B) Glucose-6-phosphate dehydrogenase

Question 17

What is the role of transaldolase in the pentose phosphate pathway?

Answer 17

Transaldolase facilitates the transfer of three-carbon units between sugars.

Question 18

Fill in the blank: The pentose phosphate pathway is also known as the _______ pathway.

Answer 18

phosphogluconate

Question 19

What type of reaction does glucose-6-phosphate dehydrogenase catalyze?

Answer 19

An oxidation reaction.

Question 20

True or False: The pentose phosphate pathway can operate independently of glycolysis.

Answer 20

True.

Question 21

What is the relationship between the pentose phosphate pathway and oxidative stress?

Answer 21

The pentose phosphate pathway helps to mitigate oxidative stress by providing NADPH for the regeneration of glutathione.

Question 22

Multiple Choice: Which substrate enters the pentose phosphate pathway? A) Fructose B) Glucose-6-phosphate C) Pyruvate D) Acetyl-CoA

Answer 22

B) Glucose-6-phosphate

Question 23

What is the primary control point of the pentose phosphate pathway?

Answer 23

The activity of glucose-6-phosphate dehydrogenase.

Question 24

Fill in the blank: The pentose phosphate pathway is particularly active in _______ tissues.

Answer 24

lipogenic

Question 25

True or False: The non-oxidative phase produces energy in the form of ATP.

Answer 25

False.

Question 26

What is the significance of ribulose-5-phosphate in nucleotide synthesis?

Answer 26

Ribulose-5-phosphate is a precursor for ribose-5-phosphate, which is essential for nucleotide synthesis.

Question 27

Fill in the blank: The pentose phosphate pathway is linked to the metabolism of _______.

Answer 27

glucose

Question 28

Multiple Choice: Which of the following metabolites can be produced from the non-oxidative phase? A) Glyceraldehyde-3-phosphate B) Acetyl-CoA C) Citrate D) Lactate

Answer 28

A) Glyceraldehyde-3-phosphate

Question 29

What is the role of NADP+ in the pentose phosphate pathway?

Answer 29

NADP+ acts as an electron acceptor in the oxidative reactions.

Question 30

True or False: The pentose phosphate pathway is a one-way process.

Answer 30

False: It can operate in both directions depending on cellular needs.

Question 31

What is the primary source of NADPH in a cell?

Answer 31

The pentose phosphate pathway.

Question 32

Fill in the blank: The pentose phosphate pathway helps in the synthesis of _______ fatty acids.

Answer 32

unsaturated

Question 33

Multiple Choice: Which of the following is a product of the oxidative phase of the pentose phosphate pathway? A) NADH B) Ribose-5-phosphate C) Fructose-6-phosphate D) Glycerol

Answer 33

B) Ribose-5-phosphate

Question 34

What is the final carbohydrate product of the non-oxidative phase?

Answer 34

Fructose-6-phosphate.

Question 35

True or False: The pentose phosphate pathway is important for red blood cell function.

Answer 35

True.

Question 36

What type of cells rely heavily on the pentose phosphate pathway for NADPH production?

Answer 36

Cells involved in fatty acid and steroid synthesis, such as liver and adipose tissue cells.