5P Pathway

Cellular Metabolism - CH25
Cell Metabolism

Metabolism of Glucose 6-phosphate into NADPH for nonphotosynthetic organisms

NADPH

Pentose Phosphate Pathway/Phosphogluconate Pathway/Hexose Monophosphate Shunt

• Glucose 6-phosphate + 2NADP + H2O <-> Ribulose 5-phosphate + 2 NADPH + 2H + CO2

Fundamentals:

• Converting Ribulose 5-phosphate into Ribose 5-phosphate
  • Precursors for RNA, DNA, ATP, NADH, FAD and coenzyme A
• Linked to Glycolysis through Transketolase, Transaldolase
• Ribulose 5-phosphate (Ru5P) can convert into Ribose 5-phosphate (Ro5P) and Xylulose 5-phosphte (Xy5P)

Regulation of Pentose Phosphate Pathway

• 5P Pathway Regulation

Stages:

• 1-Oxidative generation of NADPH
• 2-Nonoxidative interconvrsion of sugars
  • 3,4,5,6,7 carbon sugars in a series of reactions
  • Excess five carbon sugars may be converted into intermedaites of the glycolytic pathway

Detailed Steps:

• 5P Steps

Saleint Chemicals:

• Glucose 6-phosphate

LOC:

Micro

• Cytosol

Macro

• NOT IN SKELETAL MUSCLE
• Endocrine System
  • Adrenal Gland
    • Steroid Synthesis
  • Testes
    • Steroid synthesis
  • Ovary
    • Steroid synthesis
• Liver
  • Fatty acid and cholesterol synthesis
• Adipose Tissue
  • Fatty acid synthesis
• Mammary Gland
  • Fatty acid synthesis
• Red Blood Cells
  • Maintenance of reduced glutathione

Salient Diseases/Conditions:

• G6P Dehydrogenase Deficiency

Additional Information:

• Wikipedia
• Univ Montana