AQA A LEVEL BIOLOGY PAPER 1 2021

AQA A LEVEL BIOLOGY PAPER 1 2021. Describe the induced-fit model based on enzyme action and how an enzyme acts as a catalyst. [3 marks] . 2 Scientists investigated the action based on the enzyme ATP synthase. They made reaction mixtures each containing: • ATP synthase • buffer (to control pH) • substrates. One based on the substrates required within these reaction mixtures is inorganic phosphate (Pi). Tick ( ) one box to show which other substrate the scientists must add to the reactionmixtures to produce ATP. [1 mark] Adenine Adenosine diphosphate Glucose Ribose 0 1 0 1 . Downloaded by: nurse001 | Distribution of this document is illegal S - The Marketplace to Buy and Sell your Study Material 3 *03* IB/H/Jun21/7402/1 3 4 8 . The scientists investigated the effect based on concentration based on inorganic phosphate (Pi) onATP synthase activity. After 2 minutes, they stopped each reaction and then measured the concentration based on ATP. Do not write outside the box Figure 1 shows the scientists’ results. Figure 1 Suggest and explain a procedure the scientists could have used to stop each reaction. [2 marks] . Explain the change within ATP concentration with increasing inorganic phosphate concentration. [2 marks] Turn over ► 0 1 0 1 Downloaded by: nurse001 | Distribution of this document is illegal S - The Marketplace to Buy and Sell your Study Material l 4 *04* IB/H/Jun21/7402/1 . 1 Explain the advantage for larger animals based on having a specialised system that facilitates oxygen uptake. [2 marks] Do not write outside the box 0 2 Downloaded by: nurse001 | Distribution of this document is illegal S - The Marketplace to Buy and Sell your Study Material 5 *05* IB/H/Jun21/7402/1 2 Figure 2 shows two models based on oxygen uptake found within animals. Figure 2 Do not write outside the box . Suggest how the environmental conditions have resulted within adaptations based on systemsusing Model A rather than Model B.