Pathway

Question 1

What is the primary function of the pentose phosphate pathway?

Answer 1

The primary function is to generate NADPH and ribose-5-phosphate for nucleotide synthesis.

Question 2

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

Answer 2

False: It occurs in the cytoplasm.

Question 3

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

Answer 3

phosphogluconate

Question 4

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

Answer 4

Oxidative phase and non-oxidative phase.

Question 5

What is produced during the oxidative phase of the pentose phosphate pathway?

Answer 5

NADPH and ribulose-5-phosphate.

Question 6

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

Answer 6

Glucose-6-phosphate dehydrogenase.

Question 7

True or False: The pentose phosphate pathway is an anabolic pathway.

Answer 7

True.

Question 8

What is the role of NADPH in cellular metabolism?

Answer 8

NADPH is used as a reducing agent in biosynthetic reactions.

Question 9

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 9

B) ATP

Question 10

What is ribose-5-phosphate used for?

Answer 10

It is used for the synthesis of nucleotides and nucleic acids.

Question 11

Fill in the blank: The enzyme ______ catalyzes the conversion of ribulose-5-phosphate to ribose-5-phosphate.

Answer 11

ribose-5-phosphate isomerase

Question 12

What can ribulose-5-phosphate be converted into during the non-oxidative phase?

Answer 12

Xylulose-5-phosphate and ribose-5-phosphate.

Question 13

True or False: The pentose phosphate pathway is entirely reversible.

Answer 13

False: It has irreversible steps.

Question 14

What is the significance of the enzyme transaldolase in the pentose phosphate pathway?

Answer 14

It transfers a three-carbon unit from a ketose to an aldose.

Question 15

Multiple choice: Which of the following is a key regulatory enzyme of the pentose phosphate pathway? A) Phosphofructokinase B) Glucose-6-phosphate dehydrogenase C) Citrate synthase D) Lactate dehydrogenase

Answer 15

B) Glucose-6-phosphate dehydrogenase

Question 16

What role does insulin play in the regulation of the pentose phosphate pathway?

Answer 16

Insulin stimulates the activity of glucose-6-phosphate dehydrogenase.

Question 17

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

Answer 17

lipogenic

Question 18

What happens to excess glucose-6-phosphate if the pentose phosphate pathway is saturated?

Answer 18

It is diverted into glycolysis or glycogen synthesis.

Question 19

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

Answer 19

True.

Question 20

What are the two main products of the oxidative phase of the pentose phosphate pathway?

Answer 20

NADPH and ribulose-5-phosphate.

Question 21

Multiple choice: In which cellular compartment does the pentose phosphate pathway primarily occur? A) Nucleus B) Mitochondria C) Cytoplasm D) Endoplasmic reticulum

Answer 21

C) Cytoplasm

Question 22

What is the function of xylulose-5-phosphate in the non-oxidative phase?

Answer 22

It can be converted into ribose-5-phosphate or used to regenerate glucose-6-phosphate.

Question 23

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

Answer 23

fatty acid

Question 24

What is the role of the enzyme glucose-6-phosphate dehydrogenase in the pentose phosphate pathway?

Answer 24

It catalyzes the first and rate-limiting step of the pathway.

Question 25

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

Answer 25

True.

Question 26

Multiple choice: Which of the following is an important intermediate in nucleotide synthesis? A) Glyceraldehyde-3-phosphate B) 3-Phosphoglycerate C) Ribose-5-phosphate D) Acetyl-CoA

Answer 26

C) Ribose-5-phosphate

Question 27

What type of reaction is catalyzed by transketolase in the non-oxidative phase?

Answer 27

It catalyzes the transfer of a two-carbon unit.

Question 28

Fill in the blank: The pentose phosphate pathway is crucial for cells that are rapidly ______.

Answer 28

dividing

Question 29

True or False: The pentose phosphate pathway generates ATP.

Answer 29

False.

Question 30

What is the impact of oxidative stress on the pentose phosphate pathway?

Answer 30

It can increase the demand for NADPH to combat oxidative damage.

Question 31

Multiple choice: Which of the following conditions would likely increase the activity of the pentose phosphate pathway? A) Low glucose levels B) High NADPH levels C) High insulin levels D) Low ribose-5-phosphate levels

Answer 31

C) High insulin levels

Question 32

What is a potential consequence of glucose-6-phosphate dehydrogenase deficiency?

Answer 32

Increased susceptibility to oxidative stress and hemolytic anemia.

Question 33

Fill in the blank: The pentose phosphate pathway is essential for the regeneration of ______ in cells.

Answer 33

glutathione

Question 34

True or False: The pentose phosphate pathway is linked to the metabolism of nucleotides.

Answer 34

True.

Question 35

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

Answer 35

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

Question 36

Multiple choice: Which condition can lead to increased flux through the pentose phosphate pathway? A) Increased fatty acid synthesis B) Decreased glucose availability C) Increased ATP demand D) Decreased ribose-5-phosphate demand

Answer 36

A) Increased fatty acid synthesis

Question 37

Fill in the blank: The pentose phosphate pathway is particularly important in ______ cells.

Answer 37

adipose

Question 38

What is the function of NADPH produced in the pentose phosphate pathway?

Answer 38

It is used in reductive biosynthetic reactions and antioxidant defense.

Question 39

True or False: The pentose phosphate pathway is involved in the detoxification of reactive oxygen species.

Answer 39

True.

Question 40

What is the primary source of ribose-5-phosphate for nucleotide synthesis in the cell?

Answer 40

The pentose phosphate pathway.

Question 41

Multiple choice: Which of the following substrates enters the pentose phosphate pathway? A) Fructose B) Galactose C) Glucose D) Lactate

Answer 41

C) Glucose

Question 42

Fill in the blank: The pentose phosphate pathway can generate ribose-5-phosphate from ______.

Answer 42

glucose-6-phosphate