Milk contains lactose which some people can digest but some cannot.

State what type of sugar lactose is.

Milk contains lactose which some people can digest but some cannot.

State a function of lactose.

Milk contains lactose which some people can digest but some cannot.

Explain the production of lactose-free milk.

disaccharide.

provide energy (for young mammals)
Do not accept energy storage.

a. lactase added to milk / lactase immobilised;
b. lactose hydrolysed/broken down into glucose and galactose;
c. for people who are lactose intolerant/lack lactase;
d. increases sweetness/solubility/smooth texture (in processed foods);

Most candidates got this one right. Wrong answers included answers like polysaccharide, sucrose, monosaccharide and ribose.

Too many missed the idea of "function" here. Even after getting the answer to part (a) right, some candidates confused lactose with lactase citing that it as an enzyme, or suggesting that it digests. Others gave a nutrient value of milk rather than recognizing that lactose is a component of milk with a singular function.

This question could be interpreted as asking for the steps in a procedure (an acceptable expectation from Topic 3 AS 3.6.5) or it could be seen as asking the purpose of production of lactose-free milk (as found in the teacher's notes). Marking points were given for both possibilities. Most candidates earned one mark for statements about how lactose free milk is made and one mark for a reason for making it.
The old lactose/lactase/lactate confusion arose for weaker candidates. There was quite a bit of evidence for strict memorization here.
Many creative incorrect answers such as genetic modification of cows so they don’t produced lactose or lactose is an enzyme that makes digestion difficult so lactose must be denatured.