Pentose Phosphate Pathway Flashcards
What is the purpose of the pentosephosphate pathway?
- Generates reducing power in the form of NADPH
- Generates ribose 5-phosphate
What is purpose of ribose-5-phosphate?
Used in the synthesis of nucleic acids
Where does the pentose phosphate pathway occur?
Cytosol
What is phase I of the pentose phosphate pathway?
Oxidative generation of NADPH
What is phase II of the pentose phosphate pathway?
A series of reversible non-oxidative reactions that link the pentose phosphate pathway back to glycolysis
What is the purpose of different modes of the pentose phosphate pathway?
To provide the cell with the products most needed by the cell at a certain time
Which activated carrier does the pentose phosphate pathway generate?
NADPH
What occurs in phase 1 of the pentose phosphate pathway?
Oxidative generation of NADPH
What occurs in phase 2 of the pentose phosphate pathway?
A series of reversible non-oxidative reactions that link the PPP back to glycolysis
What is the sum of the non-oxidative reactions of the pentose phosphate pathway?
3 ribulose-5-phosphate ↔ 2 fructose-6-phosphate + G3P
Why are the non-oxidative reactions important?
Fructose-6-phosphate and G3P are intermediates in glycolysis
What are the 4 different modes of the PPP?
- Much more ribose-5P than NADPH required
- 2-Needs for NADPH and ribose-5P are balanced
- Much more NADPH than ribose-5P is required
- Both NADPH and ATP are required
What happens to the oxidative phase in mode 1 of the PPP?
It is switched off
What happens to the oxidative pathway in mode 3 of the PPP?
It is activated
What occurs in mode 3 of the PPP?
Gluconeogenesis can be switched on to make glucose-6-phosphate
