Respiration

IGCSE Biology

1. Respiration

2. LO: State the uses of energy in the body of humans : muscle contraction, protein synthesis, cell division, active transport, growth , the passage of nerve impulses and the maintenance of a constant body temperature State that respiration involves the action of enzymes in cells

3. LO: Define aerobic respiration as the chemical reactions in cells that use oxygen to break down nutrient molecules to release energy State the balanced chemical equation for aerobic respiration as C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O Investigate the uptake of oxygen by respiring organisms , such as arthropods and germinating seeds Investigate the effect of temperature on the rate of respiration of germinating seeds

4. LO: Define anaerobic respiration as the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen State the balanced chemical equation for anaerobic respiration in the microorganism yeast as C 6 H 12 O 6 → 2C 2 H 5 OH + 2CO 2 State that anaerobic respiration releases much less energy per glucose molecule than aerobic respiration

5. LO: State that lactic acid builds up in muscles and blood during vigorous exercise causing an oxygen debt Outline how the oxygen debt is removed during recovery

6. LO: define the term respiration Respiration the set of chemical reactions that break down nutrient molecules in living cells to release energy Definition: respiration is the release of energy from food substances, and goes on in all living cells respiration involves the action of enzymes in cells

7. Energy = capacity for doing work Needed for life Source of energy = sun Energy conversions : First conversion = photosynthesis Second conversion = respiration

8. LO: State the uses of energy in the body of humans The use of energy Growth (proteosynthesis) – protein synthesis Maintenance of a constant body temperature Active transport Cell division Movement – muscle contraction The passage of nerve impulses

9. LO: Know the form of energy found in human body ATP Adenosine triphosphate Small packet of energy which can drive the reactions in a cell Short-term store of energy

10. LO: Define aerobic respiration ;State the balanced chemical equation for aerobic respiration Aerobic respiration the release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of oxygen chemical reactions in cells that use oxygen to break down nutrient molecules to release energy Takes place in mitochondria Some energy is lost as heat

11. LO: Define anaerobic respiration; state the word equation Anaerobic respiration the release of a relatively small amount of energy by the breakdown of food substances in the absence of oxygen Word equation : in muscles during hard exercise glucose → lactic acid microorganism yeast glucose → alcohol + carbon dioxide

12. LO: State the balanced chemical equation for anaerobic respiration in the microorganism yeast as balanced chemical equation for anaerobic respiration in the microorganism yeast C 6 H 12 O 6 → 2C 2 H 5 OH + 2CO 2 Glucose alcohol and carbon dioxide

13. Anaerobic respiration releases much less energy per glucose molecule than aerobic respiration!!!

14. LO: State that lactic acid builds up in muscles and blood during vigorous exercise causing an oxygen debt Oxygen debt Lactic acid produced by muscles during anaerobic respiration is carried out of the muscles in the blood It is transported to the heart, liver and kidneys and is oxydated to pyruvate Heart , liver and kidneys need extra oxygen to get rid of the lactic acid , provided by the deep fast breathing that follows hard exercise

15. HOMEWORK : Pages 52-53 Describe the role of anaerobic respiration in yeast during brewing and bread-making.