B2 - Biology Notes (CGP GCSE Biology Book)

Inside Living Cells:

Respiration:

- Process of breaking down glucose to release energy. Occurs in every cell in your body.

- All living things respire.

- Energy is used to build larger molecules (proteins etc), contract muscles and maintain body temp.

- Aerobic respiration needs oxygen. Most efficient type of respiration.

- Glucose + Oxygen -> Carbon Dioxide + Water (+ energy).

- Circulatory system carried glucose, oxygen and CO2 around the body in the blood.

- Glucose for respiration comes from breaking down food (digestive system).

- Oxygen comes from lungs. CO2 is breathed out.

- Smallest blood vessels are capillaries. All cells have them nearby to supply them with glucose and oxygen.

- Move from capillaries by diffusion (movement from an area of high concentration to low concentration to reach equilibrium).

- Cells use up oxygen and glucose in respiration. Low concentration in cell, so they diffuse out of capillaries into the cells.

- Cells produce CO2 in respiration.  High concentration in cell, so they diffuse out of cells into capillaries.

Respiration and Exercise:

- When you exercise you respire more.

- Muscles need more energy from respiration to contract.

- Increases respiration accelerates heart rate to get more oxygen and remove more CO2.

- In vigourous exercise you can't get enough oxygen…