Biology 9700 · AS & A Level · Transport mechanisms
Transport mechanisms — practice question
In 1972, Singer and Nicolson first put forward the fluid mosaic model of membrane structure. The model explains in detail how the parts of a membrane are arranged.
(a(i))[5]
Phospholipid molecules, protein molecules and cholesterol molecules are among the components of the cell surface membrane. In the box below, draw a labelled diagram of a section through a cell surface membrane to show how the above components are arranged within the membrane. Your diagram should also include other named membrane components. Label the inner and outer surfaces of the membrane.
(a(ii))[3]
Suggest why ‘fluid mosaic’ is an appropriate term for describing membrane structure.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “A phospholipid bilayer is shown with both an inner layer and an outer layer” …