B1.3 (respiration)

Cards (45)

  • what do foods rich in carbohydrates do?
    Provide you with energy to move and stay alive
  • what do protein rich foods do?
    Used for growth and repair of body tissues, you also need small amounts of vitamins and minerals to remain healthy
  • define metabolic rate
    The speed at which chemical reactions in your cells transfer energy from its chemical stores in food
  • the higher your metabolic rate the more...?
    Food you need to eat
  • what are some carbohydrates?
    Polymers
  • what are polymer carbohydrates made from?
    Smaller carbohydrate molecules such as sugars
  • name 2 types of sugars
    Sucrose and lactose
  • what is starch an example of?
    A carbohydrate polymer
  • What do plants often do to starch?
    Converts glucose into starch as starch is a chemical energy store
  • what breaks down carbohydrates?
    carbohydrase enzymes
  • what enzyme breaks down starch?
    Amylase
  • what are proteins a type of?
    polymer, also formed from amino acids
  • how many amino acids are there?
    20, the order in which they are joined determines the protein that is synthesised
  • what protease enzymes do?
    Break down proteins into amino acids
  • what are lipids?
    Fats and oils that you eat, they are used for a good store of energy and for insulation and buoyancy in some animals (seals)
  • what are lipids synthesised from?
    3 fatty acid molecules and a glycerol molecule
  • what enzymes break down lipids into fatty acids and glycerol​?
    Lipase
  • what happens once food molecules are fully digested?
    They turn into soluble glucose, amino acids, fatty acids and glycerol and are absorbed into your bloodstream to travel to cells that need them
  • what do sugar molecules normally have at the end of their name?
    -ose
  • what do enzymes normally have at the end of their name?
    -ase
  • where does your energy come from?
    Chemical stores in the food that you eat, to transfer this energy glucose reacts with oxygen in a series of chemical reactions called aerobic respiration
  • what is the equation for aerobic respiration?
    Glucose + oxygen ----> carbon dioxide + water
  • what is the symbol equation for Aerobic respiration?
    C6H12O6 + 6O2 -> 6CO2 + 6H2O
  • what does the aerobic respiration reaction transfer?
    Energy from its chemical energy store in glucose to another chemical energy store as ATP
  • what is ATP?
    An energy store used for all processes in the cell
  • what does ATP stand for?
    Adenosine Triphosphate
  • what is ATP used by?
    All living organisms
  • what is ATP produced during respiration used for?
    1, to synthesise larger molecules from smaller ones to make new cell material. plants make amino acids from sugars, nitrates and other nutrients so in turn the amino acids form proteins
    2, for movement, animals use ATP to contract muscle cells enabling the organism to move
    3, to stay warm, when an animals surroundings are colder than they are, they increase rate of respiration in order to transfer more energy by heating so they can keep their body at a constant temperature
  • where does respiration take place?
    Mitochondria, each chemical reaction that takes place in respiration is controlled by a specific enzyme
  • what does the number of mitochondria tell you?
    How active the cell is, eg muscle cells transfer lots of energy so contain large numbers of mitochondria and liver cells also have many mitochondria since they carry out many reactions
  • what type of reaction is respiration?
    Exothermic, energy is transferred to the surroundings by heating
  • what happens to muscles during exercise?
    they need to transfer more energy than normal when they contract. your heart and breathing rate increase to provide your cells with enough glucose and oxygen for respiration to increase
  • what happens during strenuous exercise?
    Your body starts to transfer energy from its chemical store in glucose by anaerobic respiration
  • what does anaerobic respiration allow?

    for your body to transfer extra energy for short periods of time
  • what reaction occurs during anaerobic respiration?
    Glucose ---> lactic acid
  • what happens during anaerobic respiration?
    glucose is not completely broken down, instead, poisonous lactic acid is produced
  • what are the 2 reasons why the body normally respires aerobically?
    1, aerobic respiration produces more ATP molecules per glucose molecule than anaerobic respiration produces. it produces much more and this is due to the glucose molecule being fully broken down
    2, the lactic acid produced from anaerobic respiration causes cramp, when lactic acid builds up in muscle cells, it causes pain and stops the muscle contracting. this is known as fatigue
  • define oxygen debt
    The extra oxygen needed for reacting with lactic acid and breaking it down
  • when else could anaerobic respiration take place?
    In plants and microorganisms when no oxygen is available, eg in the roots of plants in water logged soils
  • define fermentation
    anaerobic respiration in microorganisms and plant cells produces ethanol and carbon dioxide instead of lactic acid