B7.5

Aerobic respiration happens in cells. In aerobic respiration:

- oxygen is used.

- Energy is released from food chemicals such as glucose.

glucose + oxygen ----------> carbon dioxide + water ( + energy released )

The energy released in respiration is used for life process which include movement. It is the energy from respiration that enables muscles to contract.

The energy released in respiration is used to make a chemical called ATP. The energy for the contraction of muscle tissue comes directly from the breakdown of ATP. We call ATP the 'energy currency' of living things.

when you exersise, your muscle cells respire faster to provide additional energy fro movement. So, they need an increase in the rate of:

- oxygen supply                                                                                                         

- glucose supply

- carbon dioxide removal.

This is why your heart rate and breathing rate increase during exersize.

Anaerobic respiration is the type of respiration that takes place in muscle cells when they dont get enough oxygen. It is a way of releasing energy without oxygen.

glucose ---------> lactic acid ( + energy released )

Aerobic releases more energy per glucose molecule than anearobic respiration.

In anaerobic respiration, lactic acid builds up in muscles. It makes them feel sore and tired.

Oxygen is needed to break down the lactic acid and release the energy left in it. The amount of oxygen needed is called the 'oxygen dept'. However, when there is a shortage of oxygen, anaerobic is beneficial for humans and other organisms.