Site author Richard Steane
The BioTopics website gives access to interactive resource material, developed to support the learning and teaching of Biology at a variety of levels.

Examples of enzymes and their action

  • substrate(s) -enzyme- product(s)

Carbohydrases (enzymes acting on carbohydrates)

  • starch (+ water) -amylase- maltose
  • maltose (+ water) -maltase- glucose + glucose
  • sucrose (+ water) -sucrase (invertase)- glucose + fructose

  • lactose (+ water) -lactase (beta-galactosidase)- glucose + galactose
  • Lactase may also be known as beta-galactosidase

Proteases (enzymes acting on proteins)

  • proteins (+ water) -pepsin- polypeptides
  • liquid milk proteins (+ water) -rennin- coagulated milk solids

Lipases (enzymes acting on lipids)

  • fats/oils (+ water) -lipase- fatty acids + glycerol

Other (non-digestive) enzymes

  • hydrogen peroxide -catalase- water + oxygen

Have you found what you are looking for?

Do you need more examples of enzymes, not just digestive ones?
Or more details about these?
Enzymes in metabolic pathways?
Enzymes in industry?
Enzymes in cell processes?
Enzymes in plants?
Or examples from each of the 6 categories:
1 Oxidoreductases: catalyse oxidation/reduction reactions
2 Transferases: transfer a functional group (e.g. a methyl or phosphate group)
3 Hydrolases: catalyse the hydrolysis of various bonds
4 Lyases: cleave various bonds by means other than hydrolysis and oxidation
5 Isomerases: catalyse isomerization changes within a single molecule
6 Ligases: join two molecules with covalent bonds.

If you need more help, get in touch using the 'Contact via form' option at the foot of this page.

Measuring rate of reaction of enzyme-controlled reactions

    This may be achieved by directly measuring
  • appearance of product over time
  • disappearance of substrate over time.

From these measurements rate of reaction may be directly calculated.

Alternatively, using the time T taken for the reaction to reach a certain stage:
Rate of reaction prop to 1/T ( rate is inversely proportional to T)

Actually it may be easier to use 100/T or 1000/T (just to avoid excess decimal places).
Make sure you are measuring T in a consistent manner (e.g. all in seconds, or minutes [convert min:sec to decimal minutes so 2:30 becomes 2.5 min])

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