Carbohydrate Metabolism - Metabolic Pathways

Metabolic Pathways

• Carbon fixation, or photosynthesis, in which CO₂ is reduced to carbohydrate.
• Glycolysis - the oxidation metabolism of glucose molecules to obtain ATP and pyruvate
  • Pyruvate from glycolysis enters the Krebs cycle, also known as the citric acid cycle, in aerobic organisms after moving through pyruvate dehydrogenase complex.
• The pentose phosphate pathway, which acts in the conversion of hexoses into pentoses and in NADPH regeneration.
• Glycogenesis - the conversion of excess glucose into glycogen as a cellular storage mechanism; this prevents excessive osmotic pressure buildup inside the cell
• Glycogenolysis - the breakdown of glycogen into glucose, which provides a glucose supply for glucose-dependent tissues.
• Gluconeogenesis - de novo synthesis of glucose molecules from simple organic compounds. an example in humans is the conversion of a few amino acids in cellular protein to glucose.

Metabolic use of glucose is highly important as an energy source for muscle cells and in the brain, and red blood cells.