Metabolism

Question 1

Factors affecting enzyme activity

Answer 1

• enzyme concentration
• substrate concentration
• rate of removal of products
• temperature
• pH level
• presence of co-factors
• presence of enzyme inhibitors

Question 2

Anaerobic Respiration

Answer 2

• occurs in the cytoplasm
• first, glycolysis: glucose –> 2 pyruvic acid molecules
• without oxygen: pyruvic acid –> lactic acid
• glycolysis of 1 molecule of glucose will suffice for the conversion of 2 x ADP –> ATP

Question 3

Oxygen debt (caused by anaerobic resp.)

Answer 3

• lactic acid is taken to the liver where it can recombine with oxygen to form glucose, and eventually glycogen
• this process requires oxygen, therefore a debt is incurred
• this is why after vigorous exercise, one continues to breathe heavily to compensate for this debt so that the lactic acid can be converted
• therefore, anaerobic respiration can produce 2 ATP molecules

Question 4

Aerobic Respiration

Answer 4

• occurs in the cytoplasm, then the mitochondria
• first, glycolysis just like anaerobic respiration
• the pyruvic acid molecules then enter the mitochondria, where the Krebs cycle and then Electron Transport System occur
• the Krebs cycle involves the 2 pyruvic acid molecules forming 2 ATP molecules
• the ETS involves another 34 ATP molecules being produced
• therefore, aerobic respiration can produce up to 38 ATP molecules