Tissue Respiration

• Description: Tissue respiration is a complex biochemical process occurring within cells.
• Function: It involves the breakdown of glucose to release energy, primarily in the form of ATP (adenosine triphosphate) and heat. ATP serves as a readily available form of chemical energy.

External Respiration:

• Process: Involves the exchange of gases (CO₂ and O₂) through diffusion.
• Location: Occurs in the alveoli of the lungs.
• Nature: Physical process.

Cellular Respiration:

• Process: A chemical process that releases energy.
• Uses of Energy:
  • Muscle contraction (e.g., peristalsis, breathing, locomotion)
  • Synthesis of enzymes, complex carbohydrates, and hormones
  • Active uptake of nutrients (e.g., glucose, ions, amino acids)
  • Generation of heat
  • Active reabsorption of mineral salts in the kidneys.

Types of Tissue Respiration

1. Aerobic Respiration:
   • Conditions: Takes place in the presence of O₂.
   • Process: Glucose is oxidized.
   • Products: CO₂, H₂O, ATP, and heat.
   • Equation: C6H12O6+6O2→6H2O+6CO2+ATP+Heat
2. Anaerobic Respiration:
   • Conditions: Occurs in the absence of O₂.
   • Energy Production: Produces less energy compared to aerobic respiration.
   • Occurrence:
     • In muscle cells of mammals during intense physical exercise.
     • In plant tissues when O₂ levels are low.
   • Types of Anaerobic Respiration:
     • Alcoholic Fermentation:
       • Process: Formation of alcohols.
       • Equation: C6H12O6→C2H5OH+Energy
     • Lactic Acid Formation:
       • Process: Occurs in muscle cells when O₂ is low due to high energy demand.
       • Equation: C6H12O6→C2H4OHCOOH+Energy
   • Obligate Anaerobes:
     • Description: Organisms that can only carry out anaerobic respiration.
   • Facultative Anaerobes:
     • Description: Organisms that can perform both aerobic and anaerobic respiration.

Differences Between Aerobic and Anaerobic Respiration

• Oxygen Requirement:
  • Aerobic: Requires O₂.
  • Anaerobic: Does not require O₂.
• Location:
  • Aerobic: Occurs in the cytoplasm and mitochondria.
  • Anaerobic: Takes place in the cytoplasm only.
• Oxidation of Glucose:
  • Aerobic: Complete oxidation of glucose.
  • Anaerobic: Incomplete oxidation of glucose.
• Energy Released:
  • Aerobic: More energy released.
  • Anaerobic: Lower energy released.
• By-products:
  • Aerobic: By-products are heat, H₂O, and CO₂.
  • Anaerobic:
    • Fermentation: By-products are ethanol, heat, and CO₂.
    • Muscle Cells: By-products are lactic acid and heat.