Question 20N.2.SL.TZ0.a
| Date | November 2020 | Marks available | [Maximum mark: 2] | Reference code | 20N.2.SL.TZ0.a |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Outline | Question number | a | Adapted from | N/A |
Outline how the amphipathic properties of phospholipids play a role in membrane structure.
[2]
a. part hydrophobic/not attracted to water/non-polar AND part hydrophilic/attracted to water/polar; Both needed.
b. bilayer formed (formed naturally by phospholipids in water);
c. hydrophilic heads/parts face outwards AND hydrophobic tails/parts face inwards;
Do not allow water loving/hating in mpa or mpc.
Knowledge of amphipathic properties in part a was good. In b, most could state that the diagram shows a synapse. A variety of spelling is usually allowed, but in this case ‘synapsis’ was not allowed in English as this refers to the pairing of homologous chromosomes. There were some G2 comments that the X could be taken as the structure. However X clearly points to an arrow, not a structure. Most were able to gain some marks by describing the events, but some lost marks by not clearly indicating that it is the vesicle containing the neurotransmitter that moves.
