AQA A-LEVEL BIOLOGY PAPER1
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 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 in the boxes at the top of this page. 4
• Answer all questions. 5
• You must answer the questions in 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 of
this book. Write the question number against your answer(s). 8
• Show all your working. 9
• Do all rough work in this book. Cross through any work you do not want
10
to be marked.
TOTAL
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 91.
*JUN217402101*
IB/H/Jun21/E14 7402/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Describe the induced-fit model of enzyme action and how an enzyme acts as a
catalyst.
[3 marks]
0 1 . 2 Scientists investigated the action of the enzyme ATP synthase. They made reaction
mixtures each containing:
• ATP synthase
• buffer (to control pH)
• substrates.
One of the substrates required in these reaction mixtures is inorganic phosphate (Pi).
Tick () one box to show which other substrate the scientists must add to the reaction
mixtures to produce ATP.
[1 mark]
Adenine
Adenosine diphosphate
Glucose
Ribose
*02*
IB/H/Jun21/7402/1
, 3
Do not write
outside the
0 1 . 3 The scientists investigated the effect of concentration of inorganic phosphate (Pi) on box
ATP synthase activity.
After 2 minutes, they stopped each reaction and then measured the concentration of
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 in ATP concentration with increasing inorganic phosphate
concentration.
[2 marks]
8
Turn over ►
*03*
IB/H/Jun21/7402/1
, 4
Do not write
outside the
0 2 . 1 Explain the advantage for larger animals of having a specialised system that box
facilitates oxygen uptake.
[2 marks]
*04*
IB/H/Jun21/7402/1
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 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 in the boxes at the top of this page. 4
• Answer all questions. 5
• You must answer the questions in 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 of
this book. Write the question number against your answer(s). 8
• Show all your working. 9
• Do all rough work in this book. Cross through any work you do not want
10
to be marked.
TOTAL
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 91.
*JUN217402101*
IB/H/Jun21/E14 7402/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Describe the induced-fit model of enzyme action and how an enzyme acts as a
catalyst.
[3 marks]
0 1 . 2 Scientists investigated the action of the enzyme ATP synthase. They made reaction
mixtures each containing:
• ATP synthase
• buffer (to control pH)
• substrates.
One of the substrates required in these reaction mixtures is inorganic phosphate (Pi).
Tick () one box to show which other substrate the scientists must add to the reaction
mixtures to produce ATP.
[1 mark]
Adenine
Adenosine diphosphate
Glucose
Ribose
*02*
IB/H/Jun21/7402/1
, 3
Do not write
outside the
0 1 . 3 The scientists investigated the effect of concentration of inorganic phosphate (Pi) on box
ATP synthase activity.
After 2 minutes, they stopped each reaction and then measured the concentration of
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 in ATP concentration with increasing inorganic phosphate
concentration.
[2 marks]
8
Turn over ►
*03*
IB/H/Jun21/7402/1
, 4
Do not write
outside the
0 2 . 1 Explain the advantage for larger animals of having a specialised system that box
facilitates oxygen uptake.
[2 marks]
*04*
IB/H/Jun21/7402/1
