Anaerobic Respiration: ATP Yield
- In cells, there is a much lower energy yield from respiration in anaerobic conditions than in aerobic conditions
- There can be different ways in which oxygen becomes unavailable
- When oxygen supply can't keep up with demand in heavily respiring cells
- But a short supply of ATP is still required eg. vigorous exercise requiring a lot of muscle contraction
- In conditions where oxygen cannot reach the organisms eg. in waterlogged soil
- When oxygen supply can't keep up with demand in heavily respiring cells
- In anaerobic respiration, glucose is only partially oxidised meaning only a small part of its chemical energy is released and transferred to ATP
- The only ATP-producing reaction that continues is the first stage of respiration (around 2 ATP molecules per molecule of glucose)
- As there is no oxygen, none of the remaining reactions (of aerobic respiration) can take place
- This means that around 36 ATP molecules are not produced anaerobically that would otherwise have been produced in the presence of oxygen
- 2 ATP molecules is better than zero ATP molecules, so anaerobic respiration can give a short discharge of energy when oxygen runs out
- Different types of organisms produce different products when respiring anaerobically
- Plants and yeasts produce ethanol and CO2
- Animals produce lactate
Anaerobic respiration in yeast produces different products to anaerobic respiration in animals