During respiration, your body takes in oxygen, moves it to your cells, and uses it to release energy from food while producing carbon dioxide and water as waste.

Quick Scoop: What happens during respiration?

Think of respiration as your body’s energy-unlocking system that works in two big parts: breathing in and out, and tiny reactions inside your cells.

1. Breathing: Getting oxygen in, CO₂ out

When you breathe, air travels through your nose or mouth down into your lungs.

Inside the lungs, oxygen moves into your blood and carbon dioxide (a waste gas) moves from your blood into the air sacs (alveoli) to be breathed out.

Key steps:

  • You inhale: chest expands, diaphragm moves down, air enters lungs.
  • Oxygen diffuses from alveoli into blood capillaries.
  • Red blood cells carry oxygen to all body cells.
  • Cells give off carbon dioxide, which returns in the blood to the lungs.
  • You exhale: diaphragm relaxes, chest gets smaller, carbon dioxide leaves the body.

2. Inside cells: Cellular respiration (energy release)

Once oxygen reaches your cells, cellular respiration happens, mainly in structures called mitochondria (often called the cell’s “powerhouse”).

In simple terms:

  • Cells take in glucose (from food) and oxygen.
  • Glucose is gradually broken down in a series of reactions.
  • Energy is released and stored in molecules called ATP (the cell’s usable energy).
  • Carbon dioxide and water are produced as wastes.

A common overall word equation:

Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP)

3. Main stages during cellular respiration

Even in a “quick scoop,” it helps to know the three core stages.

  1. Glycolysis
    • Happens in the cytoplasm.
    • Glucose is split into two molecules of pyruvate, with a small amount of ATP produced.
  1. Krebs (citric acid) cycle
    • Happens in the mitochondrial matrix.
    • Pyruvate is broken down further, releasing carbon dioxide and loading up high‑energy carriers (NADH, FADH₂).
  1. Electron transport chain (oxidative phosphorylation)
    • Happens on the inner mitochondrial membrane.
    • High‑energy electrons move through protein complexes, pumping protons and driving ATP production; oxygen is the final electron acceptor and forms water.

4. Aerobic vs anaerobic respiration (very short view)

  • Aerobic respiration: uses oxygen, makes a lot of ATP, produces CO₂ and water.
  • Anaerobic respiration: occurs when oxygen is low, makes much less ATP and produces things like lactic acid (in muscles) or alcohol and CO₂ (in yeast).

5. Why respiration matters to you

During respiration, your body:

  • Supplies cells with oxygen needed to release energy.
  • Produces ATP so muscles, brain, and organs can work.
  • Removes carbon dioxide to help keep blood pH and internal conditions stable (homeostasis).

Respiration is happening in your cells every moment of your life, turning food and oxygen into the energy that keeps you alive and active.

Information gathered from public forums or data available on the internet and portrayed here.