Date | May 2018 | Marks available | 1 | Reference code | 18M.2.SL.TZ1.2 |
Level | Standard level | Paper | Paper 2 | Time zone | Time zone 1 |
Command term | Distinguish | Question number | 2 | Adapted from | N/A |
Question
Distinguish between the structure of amylose and the structure of amylopectin.
Suggest the reason for cellulose passing undigested through the human gut.
Draw an annotated diagram to show how a peptide bond is formed.
State two structural features that differ between RNA and DNA.
Markscheme
amylose unbranched/helical while amylopectin branched / vice versa
enzymes required to digest cellulose not present in the human gut OWTTE
OR
undigested cellulose provides bulk/fibre
a. correct structure of two amino acids
b. H2O lost
c. C from COOH of one links to N of NH2/NH3+ from the other
d. correct labelling of the peptide bond
e.g.
a. number of strands
OR
(usually) only one strand in RNA/two strands in DNA
b. base composition
OR
uracil only in RNA / thymine only in DNA
c. type of pentose
OR
ribose only in RNA / deoxyribose only in DNA