21.2 - Uses of Enzymes

Industrial uses of enzymes - Pectinase and washing powders

• Enzymes can be put to work outside living things to do useful jobs in industry and in the home.
• Each enzyme breaks down one particular substance, and works quickly without needing high temperatures.
• This lets enzymes do jobs that would otherwise be slow, costly, or need harsh conditions.

Pectinase in fruit juice production

• Pectin is a carbohydrate found in the cell walls of plant cells, where it helps hold the cells together.
• Pectinase is an enzyme that breaks pectin down. It's produced naturally by some bacteria and fungi.
• Crushed fruit on its own gives up only some of its juice, because much of the liquid is held inside the cells by their walls.
• Adding pectinase breaks down the pectin in the cell walls, so the walls fall apart and the trapped juice is released.

This gives three benefits: more juice is extracted from the same amount of fruit, the juice flows out more easily, and it is usually clearer as well.

Biological washing powders

• These contain enzymes that break down the substances making up stains.
• They turn large, insoluble stain molecules into small, soluble ones that can be rinsed away.

Different enzymes deal with different kinds of stain:

• Proteases - Break down protein-based stains such as blood, sweat, and food.
• Lipases - Break down fat-based and grease stains.
• Amylases - Break down carbohydrate- and starch-based stains.

Working at low temperatures:

• Because the cleaning is done by enzymes, biological washing powders work effectively at low temperatures, around 30°C, rather than needing a hot wash.
• Washing at a lower temperature uses less energy, so it's cheaper and gentler on fabrics, while the enzymes still digest the stains.