An enzyme is a protein that acts as a biological catalyst - it speeds up biological reactions without being changed or used up. Enzymes are folded into complex shapes that allow smaller molecules (substrates) to fit into their active site.
Immobilised enzymes are enzymes that are attached to an inert, insoluble material (eg. calcium alginate). Immobilised enzymes can be used to make lactose intolerant/cat milk through catalysing the breakdown of lactose to glucose and galactose.
- can catalyse the same reaction many times
- binding makes enzymes more stable and less likely to denature
- purification is not necessary
- requires extra time, equipment and work
- may be reduction in reaction time
- cannot be used if one of the substrates is insoluble
Enzymes in the Home
Biological detergents (eg. washing powder) may contain protease and lipase to help break down stains such as blood and egg (protease) and oil and grease (lipase). Biological detergents are more effective at low temperatures than other types of detergents.
However, some people might not use biological detergents, as they can cause allergic reactions.
Enzymes in Industry
Proteases - break down proteins. They are used to 'pre-digest' solid food and break down milk proteins into amino acids in baby food. They are also used to break down allergenic proteins in hypoallergenic food.
Carbohydrases - break down carbohydrates. They are used to convert cheaper starch syrup into more valuable glucose syrup. Lactase, another carbohydrase is used to break down lactose into simple sugars for lactose intolerant people.
Isomerase - breaks down glucose. It is used to convert glucose syrup into fructose syrup. Fructose is much sweeter than glucose and can therefore be used in smaller quantities in slimming foods.