The pentose phosphate pathway is an alternate branch off of glycolysis that occurs in the cytosol and does not produce or use ATP. It aims to generate the electron carrier NADPH and synthesize sugars that make up DNA and RNA. NADPH acts as an electron donor in biosynthesis and antioxidant processes like photosynthesis. The pathway has an oxidative phase involving two irreversible oxidation steps that generate ribulose-5-phosphate from glucose-6-phosphate. It also has a non-oxidative phase of reversible steps that synthesizes the sugars used in nucleotides.

1. PENTOSE
PHOSPHATE
PATHWAY

2. Hexose monophosphate shunt
It is an alternate branch off glycolysis
Occurs in cytosol
No ATP is produced or used

3. Aims of the process
 Generation of NADPH
 Synthesis of sugar that makes up DNA or RNA

4. NADPH
Nicotinamide adenine dinucleotide phosphate

5. NADPH
 Electron donor
NADP+ NADPH
CATABOLISM
ANABOLISM

6. Role of NADPH
 Biosynthesis of some important compounds
 Role in photosynthesis
 Helps antioxidants to fight free radicals

7. SYNTHESIS OF SUGAR FOR
NUCLEOTIDESS
 Nucleotide: building block of nucleic acids
 Components of nucleotides:

8. Other processes

9. Phases of the pathway
 The oxidative phase
 The non-oxidative phase

10. The oxidative phase
 Oxidation
 Two irreversible steps

11. Step 1
Glucose-6-
phosphate
6-phosphogluconate

12. Step 2
Ribulose-5-phosphate
6-phosphogluconate

13. The non-oxidative phase
 Handy process
 Reversible steps