KA4

• the shape of the active site is complementary to the shape of the substrate
• there is 2 types of reactions in enzymes called degradation and synthesis
• synthesis is the joining of 2 or more smaller substrates to produce a larger product
• the substance produced at the end of the reaction is called the product
• The shape and function of proteins is determined by the orders of the chain of amino acids.
• Functions of proteins include receptors, enzymes, structural proteins, antibodies and hormones
• Structural proteins function: Gives strength and supports the cells structures
• Enzymes Function: acts as a biological catalysts to speed up chemical reaction in cells
• Hormones function: carries specific messages in the bloodstream of living organisms
• Antibodies Functions: provides specific defence against foreign invaders such as pathogenic bacteria and viruses
• Receptors Function: allows cells to recognise specific substrates
• Structural Proteins Example: membrane proteins give membranes their shape and strength
• Enzymes Example: amylase speeds up the breakdown of starch molecules in animals digestive systems
• Hormones Example: Insulin signals to the mammal liver to store excess glucose
• antibodies example: immunoglobulins give specific defence against invading influenza viruses
• Receptors Example: liver cells have receptors for insulin
• The shape of an enzymes active site is specific where a specific substrates attaches to the enzymes activity site
• The reaction of substrates attaching to the enzymes active site can either be degradation or synthesis.
• The 1st step of degradation: substrates collides with active site of enzymes and becomes attached
• The 2nd stage of degradation: Enzyme degradates substrate
• The 3rd stage of degradation: products released from active site
• In degradation the enzyme molecule is uncharged and can be reused
• Synthesis reaction: uses the same steps as degradation but the substrates combine to form 1 product
• enzymes function relies on speed of reaction. If the reaction speed of the enzyme is too slow or fast cell will become the denatured, causing it to die.
• PH and temperature are factors that affect the enzymes speed which can cause the reaction to be larger/faster or smaller/slower. If the enzyme goes past its optimum rate e.g. The temperature keeps increasing, the active site of the enzyme change shape and the active site no longer fits the substrate
• Starch—>maltose

  —-> = amylase
• hydrogen peroxide——> oxygen+water

  —-> = catalase
• 1 glucose 1 Phosphate —-> starch

  —->phosphorylase