Cambridge (CIE) IGCSE Biology

Revision Notes

Topic navigation panel

Topic navigation panel

(Respiration)

Aerobic Respiration

Aerobic Respiration: Breathing Life Into Energy

 

What is Aerobic Respiration?

Aerobic respiration is how your body gets energy by breaking down food (glucose) using oxygen. This happens inside cells and releases energy in the form of ATP (adenosine triphosphate).

Think of it like a campfire: Glucose is the wood, oxygen is the air, and the energy is the heat and light.

 

Word Equation for Aerobic Respiration

Example:
When you eat something sugary (glucose) and breathe in (oxygen), your body produces waste gases (carbon dioxide and water) and releases energy for your cells to use.

 

Balanced Chemical Equation

In chemical terms, the reaction is:

 

  • C6H12O6C_6H_{12}O_6: Glucose (a sugar molecule)
  • O2O_2: Oxygen you breathe in.
  • CO2CO_2: Carbon dioxide you exhale.
  • H2OH_2O: Water produced during respiration.

 

Where Does it Happen?

Aerobic respiration takes place in mitochondria, the tiny powerhouses of your cells. These organelles are specially designed to handle oxygen and glucose to make energy.

 

Why is Aerobic Respiration Important?

Your body uses the energy from aerobic respiration for:

ActivityWhy It Needs Energy
Muscle MovementWalking, running, and even blinking.
Maintaining Body HeatKeeping warm in cold conditions.
Cell DivisionTo grow and repair your body.
Active TransportMoving nutrients in and out of cells.

 

 

 

Tuity Tip

Hover me!

Aerobic respiration needs oxygen—“aero” means air!

The products are always carbon dioxide, water, and energy.

Use the chemical equation for exact molecule ratios.

Choose Your Study Plan

MonthlyAnnualSave 20%

Plus

£4.99/month
  • Everything in Free plus...
  • Unlimited revision resources access
  • AI assistance (Within usage limits)
  • Enhanced progress tracking
  • New features soon...

Pro

£9.99/month
  • Everything in Plus plus...
  • Unlimited AI assistance
  • Unlimited questions marked
  • Detailed feedback and explanations
  • Comprehensive progress tracking
  • New features soon...
Most Popular