Respiration

Oxygen Debt

the amount of oxygen required after physical exercise to remove accumulated lactic acid.

In order to neutralise lactic acid production, we breathe heavily to take in extra oxygen. Describe this process

- The extra oxygen is called the oxygen debt - The heart continues to pump faster - The breathing rate remains high - This delivers the extra oxygen to the muscles - This pays back the oxygen debt

What is the energy that is released during respiration used for?

- To build up larger molecules using smaller ones - In animals, to enable muscles to contract - In mammals and birds, to maintain a steady body temperature in colder surroundings - In plants, to build up sugars, nitrates and other nutrients into amino acids which are then built up into proteins

Heart rate increases during exercise because....

... more oxygen and glucose is needed in the muscles for respiration. These are carried in the blood. Carbon dioxide also needs to be removed from the tissues which is carried in the blood plasma.

Respiration

A chemical reaction that takes place in all living things that breaks down fuel molecules to release energy.

Glycogen

A complex carbohydrate molecule used to store glucose in the cell.

Mitochondria

A rod shaped organelle where respiration takes place in most plant and animal cells. These have a folded inner membrane to increase their surface area.

Muscle Fatigue

Caused by a lack of oxygen reaching the muscles and the resulting build up of lactic acid. The lactic acid stops the calcium from activating the muscles

Aerobic Respiration

Glucose + oxygen → Carbon dioxide and water

Anaerobic Respiration

Glucose→Lactic acid (Humans)

What is the difference between aerobic respiration and anaerobic respiration?

aerobic respiration uses oxygen and anaerobic respiration does not use oxygen

What are the disadvantages of anaerobic respiration?

anaerobic respiration produces lactic acid which is poisonous - We can only tolerate small amounts of lactic acid in our body - If muscles are subjected to long periods of vigorous activity they become fatigued, i.e. they stop contracting efficiently - One cause of muscle fatigue is the build up of lactic acid in the muscles - Blood flowing through the muscles removes the lactic acid - During and after exercise, we breathe heavily to take in extra oxygen to oxidise the lactic acid

When is anaerobic respiration used?

when insufficient oxygen is reaching the muscles