Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
A-level
BIOLOGY
Paper 1
Thursday 6 June 2019 Morning Time allowed: 2 hours
Materials
For Examiner’s Use
For this paper you must have:
• a ruler with millimetre measurements Questio Mark
• a scientific calculator. n
1
Instructions 2
• Use black ink or black ball-point pen.
3
• Fill in the boxes at the top of this page.
• Answer all questions. 4
• You must answer the questions in the spaces provided. Do 5
not write outside the box around each page or on blank
pages. 6
• Show all your working. 7
• Do all rough work in this book. Cross through any work you do 8
not want to be marked.
9
Information 10
• The marks for the questions are shown in brackets.
TOTAL
• The maximum mark for this paper is 91.
*JUN197402101* IB/M/Jun19/E16 7402/1
,2
Answer all questions in the spaces box
provided.
0 1 .1 Describe how a non-competitive inhibitor can reduce the
rate of an enzyme-controlled reaction.
[3 marks]
*02* IB/M/
Jun19/7402/1
, 3
Do not write
outside the
Pectin is a substance found in some fruit and vegetables. box
A scientist investigated the effect of pectin on the hydrolysis of lipids
by a lipase enzyme.
His results are shown in Figure 1.
Figure 1
0 1 .2 The scientist concluded that pectin is a non-competitive inhibitor of the
lipase enzyme. Use Figure 1 to explain why the scientist concluded that
pectin is a non-competitive
inhibitor.
[1 mark]
Question 1 continues on the next page
*03* IB/M/
Jun19/7402/1
, 4
Do not write
outside the
Turn over ►
*03* IB/M/
Jun19/7402/1
Centre number Candidate number
Surname
Forename(s)
Candidate signature
A-level
BIOLOGY
Paper 1
Thursday 6 June 2019 Morning Time allowed: 2 hours
Materials
For Examiner’s Use
For this paper you must have:
• a ruler with millimetre measurements Questio Mark
• a scientific calculator. n
1
Instructions 2
• Use black ink or black ball-point pen.
3
• Fill in the boxes at the top of this page.
• Answer all questions. 4
• You must answer the questions in the spaces provided. Do 5
not write outside the box around each page or on blank
pages. 6
• Show all your working. 7
• Do all rough work in this book. Cross through any work you do 8
not want to be marked.
9
Information 10
• The marks for the questions are shown in brackets.
TOTAL
• The maximum mark for this paper is 91.
*JUN197402101* IB/M/Jun19/E16 7402/1
,2
Answer all questions in the spaces box
provided.
0 1 .1 Describe how a non-competitive inhibitor can reduce the
rate of an enzyme-controlled reaction.
[3 marks]
*02* IB/M/
Jun19/7402/1
, 3
Do not write
outside the
Pectin is a substance found in some fruit and vegetables. box
A scientist investigated the effect of pectin on the hydrolysis of lipids
by a lipase enzyme.
His results are shown in Figure 1.
Figure 1
0 1 .2 The scientist concluded that pectin is a non-competitive inhibitor of the
lipase enzyme. Use Figure 1 to explain why the scientist concluded that
pectin is a non-competitive
inhibitor.
[1 mark]
Question 1 continues on the next page
*03* IB/M/
Jun19/7402/1
, 4
Do not write
outside the
Turn over ►
*03* IB/M/
Jun19/7402/1
