Page 34 - Q & A STPM 2022 Biology

Biology STPM Chapter 7 Gaseous Exchange
Exam Tips
Exam Tips
• The more the dissociation curve of a pigment shifts to the right, the slower the
oxygen binds to the pigment but released easily.
• The more dissociation curve of a pigment shifts to the left, the faster the pigment
binds to the oxygen but released slowly.
Penerbitan Pelangi Sdn Bhd. All Rights Reserved.

Question 3

P

Semester
2

(a) With reference to the above diagram,
(i) name P and state its function. (2 marks)
(ii) as blood passes through capillaries in the lungs, it becomes
oxygenated.
Explain how the structure of haemoglobin helps in the uptake of in
the lungs. (2 marks)
The graph below shows the oxygen dissociation curves for myoglobin, M and
haemoglobin, H.

Saturation
of pigment 100 M
with oxygen
(%) 80
H
60
40

20
0
2 4 6 8 10 12 14
Partial pressure of oxygen/ kPa

159

Chapter 7.indd 159 11/2/21 9:27 AM