Pentose Phosphate Pathway

Question 1

What is the pentose phosphate pathway?

Answer 1

It is an oxidative pathway for producing NADPH and converting glucose to ribose

Question 2

What are major roles of NADPH in the cell?

Answer 2

1. Reduces glutathione which reduces ROS and prevents oxidative damage, 2. Reducing power for biosynthesis (Anabolic pathways)

Question 3

What are the four molecules in the oxidative stage of the pentose phosphate pathway?

Answer 3

1. Glucose 6-phosphate — 2. 6-Phosphogluconolactone – 3. 6-phosphogluconate — 4. Ribulose 5-phosphate

Question 4

What happens to the sugar during the oxidative phase?

Answer 4

It is oxidized and decarboxylated and reduced NADPH is yielded

Question 5

What are the effects of a Glucose 6-phosphate dehydrogenase enzyme deficiency?

Answer 5

Reduces the amount of NADPH produced, leads to less reduced glutathione which normally reduces ROS and can lead to oxidative damage

Question 6

What are the three enzymes of the oxidative stage in the pentose phosphate pathway?

Answer 6

1. Glucose 6-phosphate dehydrogenase , 2. 6-phosphogluconolactonase , 3. 6-Phosphogluconate dehydrogenase

Question 7

When converting NAD+ to NADPH, you think of the enzyme ____

Answer 7

Dehydrogenase

Question 8

What enzyme converts Ribulose 5- phosphate into Ribose 5-phosphate?

Answer 8

Ribulose 5-phosphate isomerase

Question 9

The oxidative stage of the pentose phosphate pathway is highly active in _______

Answer 9

Rapidly dividing cells

Question 10

Ribose-5-Phosphate is important substrate in ___ and ____

Answer 10

Pentose phosphate pathway and nucleic acid biosynthesis

Question 11

In the oxidative phase, one _____ is converted to a ____

Answer 11

Hexose, pentose

Question 12

In order to proceed to the non-oxidative phase, a total of ________ molecules are necessary

Answer 12

Three pentose

Question 13

What happens to two molecules of ribulose 5-phosphate?

Answer 13

One molecule is converted to Ribose 5- phosphate via ribulose 5- phosphate isomerase, one molecule is converted to xylulose 5-phosphate via ribulose 5-phosphate-3 epimerase

Question 14

Ribose 5-phosphate and Xylulose 5- phosphate combine via ______ and generate one molecule of ___ and one of _____

Answer 14

Transketolase, Sedoheptulose-7-Phosphate, Glyceraldehyde-3-Phosphate

Question 15

Sedoheptulose-7-Phosphate and Glyceraldehyde-3-Phosphate react via ____ to generate ____ and _____

Answer 15

Transaldolase, Fructose-6-Phosphate, Erythrose-4-Phosphate

Question 16

_____ combines with the remaining molecule ______ via _____ to create Fructose-6-phosphate and Glyceraldehyde-3-Phosphate

Answer 16

Erythrose-4-phosphate, Xylulose 5-phosphate, transketolase