⚡️1. Release of Free Energy from Foods

• What is the primary aim of chemical reactions in cells?

  To make energy in foods available
• Why is energy required in physiological systems?

  For muscle activity, secretion, and maintenance
• What types of energy foods can be oxidized in cells?

  Carbohydrates, fats, and proteins
• How does energy release differ between cellular oxidation and burning food?

  Cellular oxidation releases energy gradually
• What is the difference between energy needed for physiological processes and heat energy?

  Physiological processes need mechanical energy
• What is meant by "coupled reactions" in cellular processes?

  Reactions linked by enzymes and energy transfer
• What is the symbol for free energy of oxidation?

  ΔG
• How is free energy usually expressed?

  In calories per mole of substance
• How much free energy is released by complete oxidation of 1 mole of glucose?

  686,000 calories
• Why is ATP referred to as the "energy currency" of the body?

  It links energy-utilizing and energy-producing functions
• What is ATP composed of?

  Adenine, ribose, and three phosphate radicals
• What happens when one phosphate radical is removed from ATP?

  It becomes ADP
• How much energy is released when a phosphate radical is removed from ATP?

  About 12,000 calories
• What is the result of losing two phosphate radicals from ATP?

  It becomes AMP
• Where is ATP found in the body?

  In the cytoplasm and nucleoplasm of all cells
• How is ATP formed in the body?

  From the oxidation of carbohydrates, proteins, and fats
• What percentage of carbohydrates are used to form ATP in the body?

  90 percent or more
• What are the physiological functions that require ATP?

  • Active transport of molecules
  • Muscle contraction and mechanical work
  • Synthesis of hormones and cell membranes
  • Conduction of nerve impulses
  • Cell division and growth
  • Other essential physiological functions
• What are the interconversions among ATP, ADP, and AMP?

  • ATP → ADP + PO₄ + 12,000 cal
  • ADP + PO₄ → ATP + 12,000 cal
  • ADP → AMP + PO₄ + 12,000 cal
  • AMP + PO₄ → ADP + 12,000 cal