biology paper 1

• Sperm cells

  • They have long tails and a streamlined head to go faster
  • Lots of mitochondria in the tails
  • It also carries enzymes in its head to digest through the egg cell membrane
• Examples of metabolism in the body

  • Conversion of glucose to starch, glycogen and cellulose
  • The formation of lipid molecules from a molecule of glycerol and three molecules of fatty acids
  • The use of glucose and nitrate ions to form amino acids which in turn are used to synthesize proteins
  • Respiration
  • Breakdown of excess proteins to form urea for excretion
• Metabolism


  The sum of all reactions in a cell or body
• Oxygen debt


  The amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove it form the cells
• What happens to the lactic acid that builds up after intense activity

  Blood flowing through the muscles transports the lactic acid to the liver where it is converted back into glucose
• What happens to your muscles after long periods of intense activity

  Muscles become fatigued and stop contracting efficiently
• What does the incomplete oxidation of glucose lead to during this type of respiration

  A build up of lactic acid which creates an oxygen debt
• What happens if not enough oxygen is present in the muscles

  Anaerobic respiration takes place
• What does the body do during exercise to supply more oxygenated blood to the muscles

  Increases the heart rate, breathing rate and breath volume
• When will the body increase its demand for oxygen

  During exercise
• Fermentation


  Anaerobic respiration in plants and yeast
• Glucose -> ethanol + carbon dioxide (+energy)
• Which releases the greater amount of energy?(Aerobic and Anaerobic)

  Aerobic respiration
• Glucose -> lactic acid
• C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy
• Glucose + Oxygen → Carbon dioxide + Water
• What organisms use energy from respiration for

  • Chemical reactions to build larger molecules
  • Movement
  • Keeping warm
• Anaerobic respiration


  Respiration when oxygen is NOT present
• Aerobic respiration


  Respiration when oxygen is present
• Respiration


  An exothermic reaction which continuously occurs in living cells
• Where respiration takes place

  In cells
• Plants use nitrate ions that are absorbed from the soil to produce protein
• 5 things that plants use glucose for after it is produced during photosynthesis


  • Used for respiration
  • Converted into insoluble starch for storage
  • Used to produce fat or oil storage
  • Used to produce cellulose, which strengthens the cell wall
  • Used to produce amino acids for protein synthesis
• The intensity of light gets weaker by 1/radius squared further away from the source

  Photosynthesis does this also as the light intensity increases
• Limiting factor


  A factor which will limit the rate of photosynthesis if not continually provided
• Factors that affect the rate of photosynthesis (limiting factors)

  • Light intensity
  • Carbon dioxide concentration
  • Temperature
  • Amount of chlorophyll present in the leaf
• Photosynthesis


  Endothermic reaction in which energy is transferred from the environment to the chloroplasts (by light)
• 6CO2 + 6H2O -> C6H12O6 + 6O2
• Carbon dioxide + water → Glucose + Oxygem
• Monoclonal antibodies are not used in society as often as were predicted because they create more side effects than expected
• 4 uses of monoclonal antibodies

  • Diagnosis such as pregnancy tests
  • In labs to measure the levels of hormones in other chemicals in blood, or to detect pathogens
  • In research to locate specific molecules in cell or tissue by binding them with a fluorescent dye
  • To treat disease: for cancer the monoclonal antibody is bound to a radioactive substance(a toxic drug or chemical which stops cells growing and dividing).It delivers the substance to the cancer cells without harming other cells in the body
• A large amount of antibody can be collected and purified once the monoclonal antibodies have been produced from mouse lymphocytes
• Why single hybridoma cells being cloned help production of monoclonal antibodies

  They produce many identical cells that all produce the same antibody
• Why the hybridoma cell is important in producing monoclonal antibodies

  It can divide and make the antibody
• The cell generated by the mouse lymphocytes that have been combined with tumour cells


  A Hybridoma cell
• How scientists generate monoclonal antibodies in a lab

  They are produced by stimulating mouse lymphocytes to make a particular antibody
• Why monoclonal antibodies are different to normal ones


  They are specific to one binding site on one protein antigen and so are able to target specific chemicals or cells in the body
• Where monoclonal antibodies are produced


  From a single clone of cells
• What is a double blind trial

  Some patients are given a placebo
• Clinical trials

  Use healthy volunteers and patients (humans)