Overview of Respiration

  • Respiration is the process by which living organisms take in oxygen and release carbon dioxide.
  • It is a series of complex chemical reactions that occur in every living cell, providing the energy needed for life processes.
  • This energy is mostly used for growth, repair, active transport, maintaining body temperature, and the synthesis of larger molecules.

Aerobic Respiration

  • Aerobic respiration requires oxygen and is the most efficient form of respiration.
  • The overall equation for aerobic respiration in glucose is:
    • C6H12O6 (Glucose) + 6O2 (Oxygen) → 6CO2 (Carbon Dioxide) + 6H2O (Water) + Energy
  • The breakdown of glucose occurs in four stages: Glycolysis, the Link Reaction, the Krebs Cycle, and the Electron Transport Chain.
  • This process happens in the mitochondria of the cells.

Anaerobic Respiration

  • Anaerobic respiration does not require oxygen. It is a less efficient process than aerobic respiration because it releases less energy overall.
  • In humans, anaerobic respiration results in lactic acid:
    • Glucose → Lactic Acid + Energy
  • In yeast cells, anaerobic respiration results in ethanol and carbon dioxide, a process commonly known as fermentation.
    • Glucose → Ethanol + Carbon Dioxide + Energy
  • Since less energy is produced, anaerobic respiration can only be sustained for a short period of time.

Comparison of Aerobic and Anaerobic Respiration

  • While both processes provide energy, aerobic respiration releases more energy because it fully breaks down glucose into carbon dioxide and water.
  • Anaerobic respiration occurs when there is insufficient oxygen for aerobic respiration, like in intensive exercise or in low oxygen conditions.
  • Anaerobic respiration can result in muscle fatigue when lactic acid builds up in the muscle cells.

Understanding Respiration

  • While it is referred to as ‘breathing’, respiration is not the inhalation and exhalation of air but rather the use of oxygen to release energy from glucose.
  • It is an essential process for life, contributing to various functions in the body including growth, muscle movement, and maintaining body temperature. It is key to understand the role of respiration in the larger biological systems.