AQA A LEVEL BIOLOGY PAPER
1 2021
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
A-level
BIOLOGY
Paper 1
Time allowed: 2 hours
Materials
For this paper youmust have:
• a rulerwith millimetr...
aqa a level biology paper 1 2021 please write clearly in block capitals centre number candidate number surname forenames candidate signature i declare this is my own work a level biology paper 1 t
Candidate signature
I declare this is my own work.
A-level
BIOLOGY
Paper 1
Time allowed: 2 hours
Materials For Examiner’s Use
For this paper you must have:
• a ruler with millimetre measurements Question Mark
• a scientific calculator. 1
2
Instructions
3
• Use black ink or black ball-point pen.
• Fill within the boxes at the top based on this page. 4
• Answer all questions. 5
• You must answer the questions within the spaces provided. Do not write 6
outside the box around each page or on blank pages.
7
• If you need extra space for your answer(s), use the lined pages at the end based on
this book. Write the question number against your answer(s). 8
• Show all your working. 9
• Do all rough work within this book. Cross through any work you do not wantto 10
be marked.
TOTAL
Information
• The marks for the questions are shown within brackets.
• The maximum mark for this paper is 91.
, 2
Do not write
outside the
. box
0 1 . 1 Describe the induced-fit model based on enzyme action and how an enzyme acts as a
catalyst.
[3 marks]
0 1 . 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
*02*
IB/H/Jun21/7402/1
Distribution of this document is illegal
, 3
Do not write
outside the
0 1 . 3 The scientists investigated the effect based on concentration based on inorganic phosphate box
(Pi) onATP synthase activity.
After 2 minutes, they stopped each reaction and then measured the concentration based on
ATP.
Figure 1 shows the scientists’ results.
Figure 1
Suggest and explain a procedure the scientists could have used to stop each reaction.
[2 marks]
0 1 . 4 Explain the change within ATP concentration with increasing inorganic phosphate
concentration.
[2 marks]
8
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