Energy Reactions In Cells

Question 1

Define cell metabolism

Answer 1

A set of processes which derive energy and raw materials from food stuffs and use them to support repair , growth and activity of tissues.

Question 2

What are the two types of metabolism ?

Answer 2

1) catabolism : break down larger molecules into smaller molecules. This releases energy which means that catabolic reactions are exergonic. Oxidative which means it releases h atoms.
2) anabolism : synthesising larger molecules from smaller ones. Use energy released from catabolism which means they are endergonic. Reductive , uses H released from catabolism.

Question 3

Describe the relationship between anabolism and catabolism

Answer 3

• the energy released from catabolism is used for anabolism.

- the H+ ions that are released during catabolism are used during anabolism.

Question 4

What are high energy signals ?

Answer 4

• ATP
• NADPH / NADH
• FADH2
• catabolic reactions

Question 5

What are low energy signals ?

Answer 5

• AMP
• ADP
• activate anabolic reactions
• NAD+
• NADP +
• FAD

Question 6

What what is the role of creatine kinase ?

Answer 6

Converts creatine in phosphocreatine

• creatine + ATP = phosphocreatine + ADP

Question 7

How can creatinine provide a useful indication of muscle mass ?

Answer 7

• : creatine and creatine phosphate breakdown during the day to make creatinine.
• creatinine excretion per 24h is proportional to muscle mass of the individual , thus provides a measure of muscle mass.
• also creatinine concentration in urine is a marker of urine dilution which can be used to estimate true urinary loss of many substances eg hormones during pregnancy.