Glucose and galactose are examples of monosaccharides. State one other example of a monosaccharide.

There are several different types of carbohydrate. State which type of carbohydrate lactose is.

State the type of chemical reaction that occurs when lactose is digested into glucose and galactose.

Simple laboratory experiments show that when the enzyme lactase is mixed with lactose, the initial rate of reaction is highest at 48°C. In food processing, lactase is used at a much lower temperature, often at 5°C. Suggest reasons for using lactase at relatively low temperatures.

fructose/ribose/ribulose/deoxyribose other monosaccharides apart from glucose and galactose

disaccharide

hydrolysis

less denaturation / enzymes last longer at lower temperatures;
lower energy costs / less energy to achieve 5°C compared to 48°C;
reduces bacterial growth / reduces (milk) spoilage;
to form products more slowly / to control the rate of reaction;

This was a question which illustrated clearly the difference between different centres. Most had obviously been well prepared and found the factual elements simple.  

This was a question which illustrated clearly the difference between different centres. Most had obviously been well prepared and found the factual elements simple.  

This was a question which illustrated clearly the difference between different centres. Most had obviously been well prepared and found the factual elements simple.  

This was better answered than part (c) with the  use of the lower temperature often being understood to relate to less denaturation of enzymes or longer lasting enzymes or less spoilage, but some considered that it changed the amount of the monosaccharides produced rather than the rate of production.