Question 18M.3.sl.TZ1.8
| Date | May 2018 | Marks available | [Maximum mark: 3] | Reference code | 18M.3.sl.TZ1.8 |
| Level | sl | Paper | 3 | Time zone | TZ1 |
| Command term | Explain, State | Question number | 8 | Adapted from | N/A |
Polymers of α-glucose include the disaccharide maltose and the polysaccharide amylose, a type of starch. The cyclic structure of α-glucose is shown in section 34 of the data booklet.
State the specific type of linkage formed between α-glucose fragments in both maltose and amylose.
[1]
«α-1,4-»glycosidic
Accept «α-1,4-»glycoside.
Accept “ether”.
[1 mark]
A person with diabetes suffering very low blood sugar (hypoglycaemia) may be advised to consume glucose immediately and then eat a small amount of starchy food such as a sandwich. Explain this advice in terms of the properties of glucose and starch.
[2]
Glucose:
readily passes through intestine wall/dissolves in blood
OR
is immediately available for energy/respiration
OR
transported rapidly around body
Starch:
must be hydrolysed/broken down «into smaller molecules» first
[2 marks]