Lecture 3: Pentose Phosphate Pathway Flashcards
1
Q
What is PPP?
A
pentose phosphate pathway
2
Q
What kind of pathway is PPP?
A
The pentose phosphate pathway is an oxidative pathway
3
Q
What are the two major metabolic functions of the pentose phosphate pathway?
A
- Converts glucose into pentoses → such as ribose-5- phosphate, an ‘activated’ sugar used by cells to synthesize nucleotides.
- decarboxylation occurs at reaction 3
- Making NADPH → a cofactor that provides reducing power during fatty acid biosynthesis.
- Reactions 1 and 3
4
Q
Other terms for PPP
A
- pentose shunt
- hexose monophosphate pathway
- phosphogluconate pathway.
5
Q
What id NADP+ in the PPP?
A
NADP+ is used in oxidation/reduction reactions of anabolic pathways to accept 2 electrons and 1 proton (hydride ion, H-).
6
Q
Where is NADPH made during PPP?
A
PPP oxidative phase reactions of which there are 2 (reactions 1 and 3)
- The oxidative phase of the PPP begins with glucose 6-phosphate dehydrogenase and produces the first NADPH.
- The second oxidation step is carried out by 6-phosphogluconate dehydrogenase, a decarboxylation reaction that yields the second NADPH and a pentose (ribulose).
7
Q
Where is the first pentose made during PPP?
A
Reaction 3
The second oxidation step is carried out by 6-phosphogluconate dehydrogenase, a decarboxylation reaction that yields a pentose (ribulose)
