Biology 9700 · AS & A Level · Transport mechanisms

Transport mechanisms — practice question

Fig. 1.1 presents a diagram of the fluid mosaic model showing the cell surface membrane structure.
(a)[3]

Name the structures indicated by A, B and C in Fig. 1.1.

(b)[2]

Draw an arrow on Fig. 1.1 to indicate the movement of a molecule across the membrane into the cell by facilitated diffusion.

(c)[3]

Explain how the fluidity of the membrane would alter if the proportion of unsaturated fatty acids in the phospholipid bilayer increased.

(d)[1]

The R-groups of amino acids give them different properties. Suggest how the properties of the R-groups of the amino acids at position 1 of P may differ from the R-groups of the amino acids at position 2.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: A is a glycolipid

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