Theory of enzymes

• The functions of enzymes

  1. Build larger molecules from small ones eg. Protein synthesis ( making proteins) bonds from anabolic reaction.
  2. Breaks down larger molecules into smaller ones
• • Enzymes is a protein that functions as a biological catalyst
• The 3 types of enzymes in GCSE

  1. Lipase
  2. Protease
  3. Carbohydrases

  ( amylase)
• 1. Carbohydrases (Amylase) - Break down carbohydrates into simple sugars
• • Protease- Breaks down proteins into amino acids
• • Lipases- Breaks down lipids (fats) into glycerol and fatty acids
• • Biological catalyst - is a substance which speeds up the rate of the chemical reaction without being used up or changed in the reaction itself
• • Proteins are polymers of amino acids. Which creat a 3D shape.
• Name the parts of the enzyme functions

  • A-Enzyme
  • B- Substrate
  • C-Enzymes substrate complex
  • D-Enzymes product complex
  • E- Products
  • Red part of the enzyme - Active site

  
• • A Substrate is a molecule that an enzyme is acting on to speed up a chemical reaction
• • The active site is the region(the area) on an enzyme that binds(attaches) to the substrate during a reaction - The shape of the active site is highly specific o the shape of one substance (they fit together to catalyse the reaction)
• The key and lock hypothesis

  • A lock and a key is the only pair , if you have a door , you can only open one door , you cannot go and unlock other people’s door
• • Catalyst - A substance that increases the rate of a chemical reaction without being used up or changed.
• Enzymes are biological catalyst (because they are made by g organism)
• • The active site is complementary to the substrates, complementary just means they are the correct shapes to fit together.

  
• • If the substrate isn’t complementary to the enzyme then the substrate won’t be catalysed.
• • Rate of reaction is how quickly or slow the reaction takes place.
• • At first we see that as the temperature increases so does the rate of reaction and this is because as the heat increases the enzymes get more kinetic energy which increases the number of collisions between the enzymes and substrates.
  • But at about 37.8 degrees is the Optimum temperature and we see a rapid decrease on the rate of reaction.

  
• Continue of Graph temperature with the rate of reaction.

  • The decrease of the rate of reaction after the optimum temperature is because high temperatures start to break apart the bonds holding the enzymes together and so the active site starts to change shape. If it changes enough then the substrate wont be able to fit into the active site and it wont get catalysed
  • At high temperatures some enzymes might even be denatured
• • Denature means irreversible damage and no longer fits the subtrate
• The Optimum temperature is the temperature at which an enzymes activity is highest