Page 9 - Q & A STPM 2022 Biology

Biology STPM Chapter 3 Membrane Structure and Transport
Answer : A
Some proteins and phospholipids conjugate with oligosaccharides to form
glycoproteins and glycolipids on the outer surface. These are important for
cell recognition.
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Question 6 Semester
Which of the following statements is not true about the cell membrane?
A Membrane allows phagocytosis and pinocytosis to occur.
B Membrane components consist of hydrophilic and hydrophobic molecules. 1
C Fatty acid in the membrane only consists of unsaturated fatty acids.
D The transportation of soluble substances through membrane occurs by
diffusion or active transport.

Answer : C
The phospholipid molecules in the membrane have both saturated and
unsaturated fatty acids. However, unsaturated fatty acids have double bonds
that form kinks that keep the molecules from packing together, increasing
membrane fluidity.

Question 7
The table below shows the components of a cell membrane and its functions.
Components of a cell Functions
membrane
P Lecithin (i) Maintains the fluid characteristic of the
membrane.
Q Oligosaccharide (ii) As an indicator for cell recognition.
(iii) Acts as a receptor to a certain molecule
R Cholesterol such as hormone.
(iv) Gives the semipermeable and selective
S Protein characteristics to the membrane.

Which of the following is the correct match for the components of a cell
membrane and their functions?
P Q R S
A (iv) (ii) (i) (iii)
B (ii) (iii) (i) (iv)
C (iv) (i) (iii) (ii)
D (iv) (iii) (ii) (i)

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