1.8 The pentose phosphate pathway

Question 1

Give the steps of the pentose phosphate pathway

Answer 1

1. Glucose-6-Phosphate
2. 6-Phosphogluconolactone
3. 6-Phosphogluconate
4. 6-Phospho-3-ketogluconate
5. Ribulose-5-phosphate
6. Ribose-5-phosphate
7. Fructose-6-phosphate
8. (Glucose-6-phosphate)

Question 2

Draw the PPP

Answer 2

Question 3

Answer 3

• Glucose-6-phosphate dehydrogenase
• NADP⁺ → NADPH + H⁺

Question 4

Answer 4

• Lactonase
• H₂O →

Question 5

Answer 5

• 6-phosphogluconate dehydrogenase
• NADP⁺ → NADPH + H⁺

Question 6

Answer 6

• No enzyme
• → CO₂

Question 7

Answer 7

Phosphopentose isomerase

Question 8

Answer 8

Transaldolase/Transketolase

Question 9

Answer 9

Phosphohexose isomerase

Question 10

Answer 10

• Hexokinase
• ATP → ADP

Question 11

Indicate the oxidative/non-oxidative parts of the pentose phosphate pathway

Answer 11

Question 12

Location of the pentose phosphate pathway

Answer 12

Cytoplasm of every cell

Question 13

Give the importance of the pentose phosphate pathway

Answer 13

1. Generate reducing equivalents in the form of NADPH + H⁺
2. Provide cells with Ribose-5-phosphate for nucleotides
3. Rearrange carbon skeletons of dietary carbohydrates

Question 14

How is pentose phosphate pathway regulated

Answer 14

Glucose-6-phosphate dehydrogenase

• NADP⁺ Activates
• NADPH + H⁺ Inhibits