Date | November 2021 | Marks available | 1 | Reference code | 21N.1.SL.TZ0.9 |
Level | Standard level | Paper | Paper 1 | Time zone | TZ0 / no time zone |
Command term | Question number | 9 | Adapted from | N/A |
Question
Lactose can be removed from milk by passing the milk through a column of alginate beads to which immobilized lactase is bound. What is an advantage of immobilizing the enzyme?
A. It creates more active sites.
B. The alginate beads act as a coenzyme.
C. It lowers the activation energy of the reaction.
D. It allows the product to be separated easily from the enzyme.
Markscheme
D
Examiners report
Two thirds of candidates gave the expected answer, which was that enzyme immobilization makes separation of product from enzyme easier. One of the distractors was lowering of activation energy by immobilization. This has been shown to occur in some examples of immobilization, but ease of separation was thought by the assessment team to be the most significant advantage. Candidates should be encouraged to choose the best answer if more than one seems at least partially correct.