metabolism

Table of Contents

Introduction
A summary of metabolism
- The unity of life
- Biological energy exchanges
  - The carrier of chemical energy
  - Catabolism
    - Incomplete oxidation
    - Complete oxidation
  - Anabolism
- Integration of catabolism and anabolism
  - Fine control
  - Coarse control
- The study of metabolic pathways
The fragmentation of complex molecules
- The catabolism of glucose
  - Glycolysis
    - The aldolase reaction
    - The formation of ATP
  - The phosphogluconate pathway
- The catabolism of sugars other than glucose
  - Release of glucose from glycogen
  - Fragmentation of other sugars
- The catabolism of lipids (fats)
  - Fate of glycerol
  - Fate of fatty acids
    - Formation of fatty acyl coenzyme A molecules
    - Fragmentation of fatty acyl coenzyme A molecules
- The catabolism of proteins
  - Removal of nitrogen
  - Disposal of nitrogen
  - Oxidation of the carbon skeleton
The combustion of food materials
- The oxidation of molecular fragments
  - The oxidation of pyruvate
  - The tricarboxylic acid (TCA) cycle
    - Formation of coenzyme A, carbon dioxide, and reducing equivalent
    - Regeneration of oxaloacetate
    - ATP yield of aerobic oxidation
- Biological energy transduction
  - Adenosine triphosphate as the currency of energy exchange
  - Energy conservation
    - Substrate-level phosphorylation
    - Oxidative, or respiratory-chain, phosphorylation
    - The nature of the respiratory chain
    - ATP synthesis in mitochondria
    - ATP formation during photosynthesis
The biosynthesis of cell components
- The nature of biosynthesis
  - The stages of biosynthesis
  - Utilization of ATP
- The supply of biosynthetic precursors
  - Anaplerotic routes
  - Growth of microorganisms on TCA cycle intermediates
- The synthesis of building blocks
  - Gluconeogenesis
    - Formation of PEP from pyruvate
    - Hydrolysis of fructose 1,6-diphosphate and glucose 6-phosphate
  - Lipid components
    - Glycerol
    - Fatty acids
    - Other components
  - Amino acids
  - Mononucleotides
    - Purine ribonucleotides
    - Pyrimidine ribonucleotides
    - Deoxyribonucleotides
- The synthesis of macromolecules
  - Carbohydrates and lipids
    - Formation of storage polysaccharides
    - Formation of lipids
  - Nucleic acids and proteins
    - Synthesis of DNA
    - Synthesis of RNA
    - Synthesis of proteins
Regulation of metabolism
- Fine control
  - End-product inhibition
  - Positive modulation
  - Energy state of the cell
- Coarse control

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Last Updated: May 29, 2025

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mitochondria and cellular respiration

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electron transport chain

respiratory chain

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