Respiration

Respiration Overview

  • Respiration is a chemical process where energy is released from food substances, like glucose.
  • It is an exothermic reaction, meaning it releases heat.
  • Respiration happens in every cell in your body all the time.

Types of Respiration

  • There are two types of respiration: aerobic (using oxygen) and anaerobic (not using oxygen).
  • Aerobic respiration is the most efficient and releases the most energy. Its word equation is: glucose + oxygen -> carbon dioxide + water (+ energy).
  • Anaerobic respiration occurs when there is not enough oxygen available. Its word equation in muscle cells is: glucose -> lactic acid (+ energy).
  • In yeast cells (and some plant tissues), anaerobic respiration is different and produces ethanol and carbon dioxide instead of lactic acid, it is also called fermentation.

Cellular Respiration

  • Cellular respiration includes both aerobic and anaerobic respiration but is often used as another term for aerobic respiration.
  • It occurs in the mitochondria of cells.
  • Energy released during respiration is used to make a molecule called ATP (adenosine triphosphate).
  • ATP can be instantly used by cells to perform functions like muscle contraction, protein synthesis, cell division and transmission of nerve impulses.

Respiration in Plants

  • Plants respire just like any other living organism, they take in oxygen and glucose and release carbon dioxide, water, and energy.
  • Energy released is used by the plant to perform essential functions like growth and repair.
  • Respiration in plants happens all the time, unlike photosynthesis which happens only in the presence of sunlight.

Anaerobic Respiration in Sport

  • During strenuous exercise, when the demand for energy is high, anaerobic respiration in muscle cells supplement aerobic respiration.
  • Anaerobic respiration allows muscles to work for longer but produces lactic acid, causing muscle fatigue and cramps.
  • Oxygen debt refers to the extra oxygen required to break down the lactic acid build up in the muscles after exercise.

Remember, understanding respiration goes beyond memorising the equations - it’s about understanding the process and how it fits in with other biological concepts like photosynthesis and digestion. Respiration is happening in your body right now - it’s what keeps you alive!