B1

• STAR WIRE GITORIKES BREWTON

  mRNA and DNA
• Transcription


  1. DNA unzips

  2. One DNA strand acts as template

  3. Complementary bases attach

  4. mRNA strand formed
• Translation


  1. mRNA attaches to ribosome

  2. Ribosome reads nucleotide sequence

  3. Amino acids join in chain

  4. Protein formed
• The order of nucleotides in DNA and mRNA is called a triplet code
• The sequence of amino acids determines how the protein will fold
• Many types of proteins are produced, including enzymes and hormones
• Metabolic rate


  The speed at which chemical reactions transfer energy from food
• The higher your metabolic rate, the more food you need to eat
• Investigating enzymes


  1. Mix different temperature starch solutions with amylase

  2. Test for presence of starch using iodine

  3. Observe reaction over time
• Carbohydrates


  Polymers made from smaller carbohydrate molecules like sugars
• Carbohydrase enzymes

  Break down carbohydrates
• Proteins


  Polymers formed from amino acids
• Protease enzymes


  Break down proteins into amino acids
• Lipids


  Fats and oils, used for energy storage, insulation and buoyancy
• Lipase enzymes


  Break down lipids into fatty acids and glycerol
• Digested food molecules are absorbed into the bloodstream and travel to cells that need them
• Aerobic respiration


  Series of chemical reactions that transfer energy from glucose to ATP
• Aerobic respiration produces carbon dioxide and water as products
• Uses of ATP

  • Synthesise larger molecules
  • Provide energy for movement
  • Generate heat to maintain body temperature
• Mitochondria


  Subcellular components where aerobic respiration occurs
• Respiration is an exothermic reaction, transferring energy to the surroundings as heat
• Aerobic respiration has three main stages, which occur within the mitochondria
• Anaerobic respiration occurs when oxygen demand exceeds supply, producing lactic acid
• Aerobic respiration


  1. Enzyme-controlled reactions

  2. Three main stages
• Products of respiration with their chemical formulae need to be stated
• Athlete suffering from cramp

  Lactic acid builds up
• Anaerobic respiration


  1. Glucose

  2. Lactic acid
• Anaerobic respiration

  Series of chemical reactions that do not need oxygen
• Anaerobic respiration produces lactic acid
• Aerobic respiration


  • Produces more ATP molecules per glucose molecule than anaerobic respiration
  • Glucose molecule is fully broken down
• Lactic acid builds up in muscle cells

  Causes pain and muscles stop contracting (fatigue)
• After strenuous exercise


  Breathing heavily to inhale extra oxygen to react with lactic acid (oxygen debt)
• Other animals, plants and microorganisms use anaerobic respiration when they need to transfer a lot of energy quickly
• Fermentation


  1. Glucose

  2. Ethanol + Carbon dioxide
• Fermentation is another example of anaerobic respiration
• Raw materials needed for photosynthesis

  • Carbon dioxide
  • Water
• Photosynthesis produces glucose and oxygen
• Photosynthesis


  Series of chemical reactions that use light energy to convert carbon dioxide and water into glucose and oxygen
• Photosynthesis is an endothermic reaction
• Phototropism

  Growing towards the light