SCT II - Carbohydrate Metabolism II (Pentose Phosphate Pathway)

Question 1

In the oxidative stage of the pentose phosphate pathway, how are isomerases and epimerases utilized?

Answer 1

Ribose-5-Phosphate
to | Phosphopentose Isomerase
Ribulose-5-Phosphate
to | Phosphopentose Epimerase
Xylulose-5-Phosphate

Question 2

In the non-oxidative stage, what is the C2 transfer?

Answer 2

2 Carbon transfer:

[5C] Xylulose-5-Phosphate
+
[5C] Ribose-5-Phosphate
to | Transketolase
[3C] Glyceraldehyde-3-Phosphate
+
[7C] Sedoheptulose-7-Phosphate

Question 3

In the non-oxidative stage, what is the C3 transfer?

Answer 3

3 Carbon transfer:

[3C] Glyceraldehyde-3-Phosphate
+
[7C] Sedoheptulose-7-Phosphate
to | Transaldolase
[4C] Erythrose-4-Phosphate
+
[6C] Fructose-6-Phosphate

Question 4

What is an essential cofactor for both transketolase and transenolase enzymes?

Answer 4

Use Vitamin B1 (TPP) | Thiamine