Enzymes

• Organisms need enzymes as they are biological catalysts that speed up chemical reactions
• A catalyst is a substance that increases the speed of a chemical reaction without being used up in the reaction
• An enzyme is a special type of catalyst that is made by a living organism
• Active site is where an enzyme binds to a substrate
• An enzyme-substrate complex is formed when an enzyme binds to a substrate
• A substrate must be complementary to the active site of an enzyme.
• Temperature and pH are the main factors effecting enzyme activity.
• Starch is the main carbohydrate that we eat
• Starch is a polymer made of glucose
• Amylase breaks down starch into maltose molecules
• Salivary glands, pancreas and small intestine produce amylase.
• Maltose is broken down by maltase into 2 glucose molecules.
• A protein is a polymer made of amino acids
• Proteins are broken down by proteases into amino acids.
• Pepsin is an example of a protease.
• Stomach, pancreas and small intestine produce protease
• lipids are broken down by lipase enzymes into glycerol and fatty acids
• Small intestine and pancreas produce lipase enzymes
• Bile is a yellow/green liquid produced by the liver and stored in the gallbladder.
• Bile emulsifies fats and neutralises stomach acid.