Biology 9700 · AS & A Level · Testing for biological molecules
Testing for biological molecules — practice question
Triglycerides and phospholipids are both lipid types. Fig. 2.1 shows the structure of a phospholipid called phosphatidylcholine. F1 and F2 are fatty acid residues.
(a)[2]
Phospholipase is an enzyme that can hydrolyse phospholipids. It is present in the venom of some insects, including bees. Bee venom can destroy red blood cells, a process called haemolysis. Suggest how bee venom destroys red blood cells.
(b)[4]
Compare, stating similarities and differences, the structure of the phosphatidylcholine shown in Fig. 2.1 with a triglyceride molecule.
(c)[3]
Name and describe the cell structure where triglyceride and other lipid synthesis occurs.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The cell surface (plasma) membrane/phospholipid bilayer is damaged by phospholipase” …