The plasma membrane of a cell
A - VCE - SSCE Biology - Question 3 - 2005 - Paper 1
Question 3
The plasma membrane of a cell
A. is inflexible due to the presence of protein molecules.
B. allows substances to pass through only by active transport.
C. contain... show full transcript
Worked Solution & Example Answer:The plasma membrane of a cell
A - VCE - SSCE Biology - Question 3 - 2005 - Paper 1
Step 1
A. is inflexible due to the presence of protein molecules.
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Answer
This statement is incorrect. The plasma membrane is actually flexible due to its fluid mosaic model, which allows proteins to move and drift within the lipid bilayer.
Step 2
B. allows substances to pass through only by active transport.
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Answer
This statement is also incorrect. While the plasma membrane does allow for active transport, it also facilitates passive transport mechanisms like diffusion and osmosis.
Step 3
C. contains cholesterol molecules which can act as cell receptors.
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Answer
This statement is correct. The cholesterol in the membrane helps to stabilize its structure and fluidity, and while cholesterol itself isn't a receptor, it aids in the function of other proteins that can act as receptors.
Step 4
D. is relatively impermeable to large water-soluble molecules due to the presence of the bilipid layer.
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Answer
This statement is true. The bilipid layer of the plasma membrane creates a barrier to large, water-soluble molecules, requiring specific transport mechanisms for their movement.
