Life Processes long 1

Question 1

What is Anaerobic respiration?

Answer 1

To provide energy for life processes the first step is the break-down of glucose, a six-carbon molecule, into a three-carbon molecule called pyruvate taking place in the cytoplasm. The pyruvate may be converted into ethanol and carbon dioxide. This process takes place in yeast. Since this process takes place in the absence of oxygen it is called anaerobic respiration.

Question 2

What is aerobic respiration?

Answer 2

Breakdown of pyruvate using oxygen takes place in the mitochondria. This breaks up the three-carbon pyruvate molecule to give three molecules of carbon dioxide. This takes place in the presence of oxygen it is called aerobic respiration. The release of energy in this is a lot greater than in the anaerobic process.

Question 3

What happens when there is a lack of oxygen in our muscle cells during aerobic respiration ?

Answer 3

When there is a lack of oxygen in our muscle cells, another pathway for the break-down of pyruvate is taken. Here the pyruvate is converted into lactic acid which is also a three-carbon molecule.