Cambridge O Level Biology · Syllabus 5090 · Biotechnology and Genetic Modification
Biological washing powder
What is Biological washing powder?
A washing powder containing enzymes that break down the substances in stains. Proteases hydrolyse the large insoluble protein molecules in stains such as blood, egg and grass into small soluble amino acids; lipases hydrolyse the fats and oils in greasy stains into fatty acids and glycerol. Because the products are small and soluble they dissolve in the wash water and are carried away, so the stain is removed. The enzymes work effectively at moderate temperatures, so a lower wash temperature can be used and less energy is needed for heating; at very high temperatures the enzymes denature and the powder loses its effect. The powder contains isolated enzymes, not living microorganisms, and the enzymes catalyse reactions rather than eating anything.
This definition is part of the Biotechnology and Genetic Modification chapter in Cambridge O Level Biology.
Biological washing powder in context
Biotechnology is the use of living organisms, cells or enzymes to make useful products. Yeast respires anaerobically, converting glucose to ethanol and carbon dioxide: the carbon dioxide raises bread dough, and the ethanol is the product collected in ethanol manufacture. Bacteria are chosen for industrial production because they reproduce rapidly, can make complex molecules, contain plasmids that can receive selected genes, and raise fewer ethical concerns than using animals. They are grown in fermenters, in which temperature, pH, oxygen, nutrient supply and waste products are all controlled. Isolated enzymes do industrial jobs of their own — proteases and lipases in biological washing powders, pectinase in fruit juice, lactase in lactose-free milk. Genetic modification is changing an organism's genetic material by removing, changing or inserting individual genes; inserting the human insulin gene into bacterial DNA lets bacteria make human insulin, and inserting genes into crops can give herbicide resistance, insect-pest resistance or increased vitamin content — each with benefits and risks that have to be weighed rather than declared.
Questions students ask about Biological washing powder
What do the enzymes in biological washing powder do?
Proteases hydrolyse the protein in stains such as blood, egg and grass into amino acids. Lipases hydrolyse fats and oils into fatty acids and glycerol. The products are small and soluble, so they dissolve in the wash water and are carried away. The enzymes work at moderate temperatures, so less energy is needed for heating; at very high temperatures they denature.