Biology 9700 · AS & A Level · Testing for biological molecules
Testing for biological molecules — practice question
In mammals, adipocytes are cells located in adipose tissue. They take up glycerol and fatty acids and combine them to form triglycerides for long-term storage. Fig. 4.1a shows one glycerol molecule together with three fatty acids. Fig. 4.1b shows the triglyceride molecule produced from these parts.
(a(i))[1]
State the name given to the bonds that form between glycerol and fatty acids.
(a(ii))[1]
When a bond is formed between glycerol and a fatty acid, water appears among the products. State the name used for this type of reaction.
(a(iii))[3]
Describe how the fatty acids X, Y and Z in Fig. 4.1a differ from one another.
(b(i))[2]
State the reasons that triglycerides are described as hydrophobic.
(b(ii))[2]
Explain why triglycerides are unsuitable as a component of cell surface membranes.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “ester bond” …