Respiration: Respiration

10.1 Respiration

Definition

• Respiration = chemical reactions in living cells that release energy from glucose.
• Energy released is stored in ATP (adenosine triphosphate).

Uses Of Energy In Organisms

• Muscle contraction (movement).
• Protein synthesis (growth, repair).
• Cell division.
• Active transport (ion uptake in roots, glucose absorption in villi).
• Passage of electrical impulses in neurones.
• Maintenance of constant body temperature in warm-blooded animals.

Written And Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change O Level And IGCSE Biology Full Scale Course

Types Of Respiration

• Aerobic respiration – with oxygen, produces large amount of energy.
• Anaerobic respiration – without oxygen, produces less energy.

Experiment: Respiration In Yeast

• Place yeast with glucose solution in a flask.
• Provide anaerobic conditions.
• Observe production of carbon dioxide bubbles.
• Temperature affects rate: higher temp (until optimum) → faster respiration.

Key Point

• Respiration ≠ Breathing.
  • Breathing = ventilation (air in/out of lungs).
  • Respiration = chemical energy release inside cells.

Written And Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions And 11 World Records For Educate A Change O Level And IGCSE Biology Full Scale Course