B3 - B

  • Created by: zoolouise
  • Created on: 02-06-15 17:55
View mindmap
  • Proteins and mutations
    • Grouping organisms
      • All proteins are made of long chains of amino acids
      • Proteins have different functions.
        • Structural proteins are used to build cells and tissues e.g collagen
        • Enzymes
        • Hormones which carry messages to control a reaction e.g insulin
        • Carrier proteins e.g haemoglobin
      • Each protein has its own number and order of amino acid.
        • This gives each type of protein molecule a different shape and function.
    • Enzymes
      • Enzymes speed up reactions in the body and are therefore called biological catalysts.
      • They catalyses chemical reactions occurring in respiration, photosynthesis and protein synthesis in living cells.
      • The subtract molecule fits into the enzyme active site like a key fitting into a lock, hence the'lock and key mechanism'
        • This explains why each enzyme can only work on a certain substrate. It's called specificity and happens as the substrate has to be the right shape.
      • Enzymes all work best at a certain pH and temperature, this is called the optimum and any change away from it slows down the reaction.
        • At low temperatures molecules are moving more slowly and the enzyme and substrate are less likely to collid.
          • At very high or low pH's or very high temperatures the enzyme active site starts to denature and therefore the substrate cannot fit and it can't react as quickly.
      • Calculating the Q10 works out how temperature alters rate of reaction.
    • Mutations
      • Mutations may occur spontaneously but can be made to occur by chemicals and radiation
      • When they occur they can give an individual an advantage, be harmful but with no effect, produce a different protein
      • Every cell has the same genes but doesnt mean the same proteins are made. Different genes are switched off in diff cells, allows diff cells to perform diff functions.
      • Mutations alter or prevent production of protein thats normally made, they change the base code of DNA and therefore the order of amino acids im proteins.


No comments have yet been made

Similar Science resources:

See all Science resources »See all Biology resources »