Enzymes and Respiration
- respiration is NOT breathing, it releases energy that the cell needs to function
- respiration involves many reactions that are catalysed by enzymes
- Respiration is the process of releasing energy from glucose which goes on in every cell.
- AEROBIC respiration: - uses oxygen, the most efficient way to release energy from glucose. - goes on all the time in plants and animals. - most reactions happen inside mitochondria, word equation: Glucose + Oxygen ----> Carbon Dioxide + Water + ENERGY
- Respiration releases energy for many different things: the energy released by aerobic respiration is used for:
- to build up larger molecules from smaller ones, like proteins from amino acids
- in animals - allowing the muscle to conract
- in mammals and birds - energy keep body temperature steady
- in plants - builds up sugars, nitrates and other nutrients in amino acids that are built up to proteins.
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Uses of Enzymes
- Used in biological detergents:
- enzymes are "biological" ingredients in detergents and washing powders. They are mainly protein-digesting enzymes (protease) and fat-digesting enzymes (lipases). as enzymes break down animal and plant matter, they are good for removing stains like food or blood. Biological detergents are more effective at working at low temperatures
- Enzymes are used to change foods:
- the proteins in baby food are pre-digested using protein-digesting enzymes (protease) so they become easier to digest. Carbohydrate-digesting enzymes (carbohydrase) can be used to turn starch syrup into sugar syrup. Glucose syrup can be turned into fructose syrup using isomerase, fructose is sweeter so less is needed.
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Enzymes in Industry
- really useful in industry as they speed up reactgions without high temperatures and pressures
- they're specific so only cataylse the reaction you want them to, also, they work for a long time so after the initial cost, they are continually in use.
- use lower temperatures and pressures = lower cost and saves energy
- biodegradable and cause less environmental pollution.
- some people develop allergies to the enzyme
- enzymes can be denatured by a small increase in temperature, they are susceptible to poisons and changes in pH = the conditions need to be tightly controlled
- enzymes can be expensive to produce
- contamination of enzymes with other substances can affect the reaction
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