User interface language: English | Español

Date November 2017 Marks available 2 Reference code 17N.2.SL.TZ0.05
Level Standard level Paper Paper 2 Time zone TZ0 / no time zone
Command term State Question number 05 Adapted from N/A

Question

State one disaccharide and the two monomers from which it can be synthesized.

Disaccharide:

 1:

Monomers:

1:

and 2:

 

 

[2]
a.

Discuss the roles of the enzymes secreted by the pancreas during digestion.

[3]
b.

Compare and contrast cis-fatty acids and trans-fatty acids.

[2]
c.

Markscheme

a. disaccharide name

    eg: lactose, glucose and galactose

b. both monomers that make up mpa

    eg: maltose, glucose and glucose

    eg: sucrose, glucose and fructose

a.

a. amylase breaks down/catalyzes/hydrolyses starch to maltose

b. lipase breaks down/catalyzes/hydrolyses fats to fatty acids and glycerol

c. proteases/peptidases break down/catalyze/hydrolyze proteins into smaller
polypeptides/dipeptides/amino acids

Award [2] if all three enzymes and substrates named correctly and one further mark for all three products named
correctly.

Allow specific enzymes

b.

a. both are unsaturated fatty acids

    OR

    both have two carbon atoms joined by a double bond

b. in cis-fatty acids the two H atoms are on the same side while in trans-fatty acids they are on opposite sides

    OR

    cis-fatty acids are healthier than trans-fatty acids

    OR

    cis-fatty acids have a lower boiling/melting point than trans

    OR

    cis-fatty acids have a kink «in the chain» but trans do not

Accept answer in an annotated diagram

c.

Examiners report

[N/A]
a.
[N/A]
b.
[N/A]
c.

Syllabus sections

Core » Topic 2: Molecular biology » 2.1 Molecules to metabolism
Show 36 related questions
Core » Topic 2: Molecular biology
Core

View options