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Proteins,Catalysts and enzymes

• -Protein molecules are made up of long chains of Amino acids.Break down large molecules into smaller ones,for example, all the digestive enzymes can do this-The shape of a protein depends on its function:
• -structural components of tissues,such as muscle -hormones-antibodies-catalysts
• Chemical reactions in cells are caused by proteins called enzymes,which are biological catalysts.
• The substrate in a reaction can either be connected to another molecule or broken down.Enzymes can:Build starch from glucose molecules by breaking them down to make starch moleculeschange one molecule into another,for example, changing one type of sugar into another.

Factors affecting enzyme action

• r-Reactions take place faster when it is warmer.At high temp the molecules move around more quickly and collide more often and with more energy.
• -Denatured means that if an enzyme gets to hot and stops working it is because the active site changes shape.-Some enzymes work in acidic conditions ,for example, the stomach but some enzymes work better in neutral or alkaline conditions.
• -If the pH becomes too acidic or too alkaline for an enzyme,then the active site could change shape. Then the enzyme becomes denatured.

Enzymes in digestion

• Digestion involves the breakdown of insoluble molecules into soluble molecules.
• Specific enzymes
• -Amylase is produced by the salivery glands, the pancreas and the small intestine.
• -Protease is produced by the stomach, the pancreas and the small intestine.
• -Lipase is produced by the pancreas and the small intestine. Lipase catalyses the breakdown of lipids to fatty acids and glycerol

Speeding up digestion

• -Protease enzymes work better in acidic conditions.Glands in the stomach produce hydrochloric acid to create very acidic conditions
• -Amylase and lipase work in the small intestine.They work best when the conditions are slightly alkaline.
• -The liver produce bile that is stored in the gall bladder.the alkaline bile is squirted into the small intestine and neutralises the stomach acid.Bile make the conditions in the intestine slightly alkaline.

Making use of enzymes

• -Biological detergents contain proteases and lipases that digest food stains.They work at lower temps.This saves energy and money spent on electricity.
• -Isomerase is used to convert glucose syrup into fructose syrup.
• -Carbohydrases are used to convert starch into sugar syrup for use in foods.
• -Traditional chemical processes require expensive equpment and a lot of energy to produce high temps and pressures.

High tech enzymes

• Advantages of using enzymes:
• -In industry, costs of equipment and energy can be reduced
• -Some enzymes are used in medicine to diagnose, control or even cure disease.
• - Bio washing powders can be used at low temp.This saves energy and reduces costs.
• Disadvantages of using enzymes:
• -Enzymes may enter water ways via the sewage system.
• -Industrial enzymes can be costly to produce.
• - Some fabrics such as wool will be digested by proteases.