Biology 9700 · AS & A Level · Respiration

Respiration — practice question

Every cell requires ATP for energy-demanding processes in the body. Fig. 7.1 displays the molecular structure of ATP.
(a(i))[1]

Name the base at label X.

(a(ii))[1]

Name the sugar at label Y.

(b)[3]

State three reasons why ATP serves as an energy currency in all living organisms.

(c)[3]

ATP is generated in three stages of aerobic respiration. Complete the table to show two products of each stage, apart from ATP, for: • glycolysis • Krebs cycle • oxidative phosphorylation.

(d)[2]

Carbohydrates and lipids can both act as respiratory substrates. Table 7.1 gives the energy values of carbohydrates and lipids in $\text{kJ g}^{-1}$. Explain why lipids have a greater energy value than carbohydrates.

(e(i))[2]

State how the respiratory quotient (RQ) is worked out.

(e(ii))[2]

Give the usual RQ values that arise from carbohydrate respiration and lipid respiration. carbohydrate .................... lipid ....................

(e(iii))[1]

Suggest how the RQ value changes when respiration in yeast becomes anaerobic.

Worked solution & mark scheme

This 15-mark question has a full step-by-step worked solution and mark scheme. One marking point: adenine base

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI