(a)[4]
Describe the functions of the mitochondrial membranes in respiration.
(b(i))[2]
Suggest reasons for mitochondrial fission.
(b(ii))[1]
Guanosine triphosphate (GTP) is a molecule used as an energy source in some reactions instead of ATP. Guanosine consists of a purine, similar to adenine, and ribose. Suggest why GTP is a suitable energy source in some reactions.
(c)[2]
Old or damaged mitochondria lower the ability of a cell to carry out aerobic respiration and make the ATP required for the cell's metabolic activities. Suggest what happens to these mitochondria so the cell can keep the same overall rate of respiration and ATP production.