Biology B4

Biology B4

1. B4.3

   • Synthesis
     • Of polymers
       • Required by plant cells
         • Such as starch cellulose from glucose
     • Amino acids
       • From glucose and nitates
       • Proteins in plants
   • Respiration
     • Aerobic
       • Requires Oxygen
         • Glucose+Oxygen---> Carbon Dioxide + Water
       • Releases more energy per glucose molecule
     • Takes place in animal & plant cells
       • Sometimes microorganisms
     • Anaerobic
       • Low oxygen
         • Or none
         • Animal cells and bacteria
           • Glucose---> Lactic acid
         • Plant cells and microorganisms
           • Glucose---> Ethanol+Carbon dioxide
           • Applications of anaerobic respiration of microorganisms
             • Production of bio gas and fermentation
               • In bread making
               • In alcohol fermentation
       • Plant roots in waterlogged soil
       • Bacteria in puncture wounds
       • Human cells during vigorous excercise

2. B4.2

   • Plant cell
     • Cell Membrane
       • Allows gases and water to pass through
         • Controls passage of other molecules
     • Nucleus
       • Contains genetic code for enzymes
     • Cytoplasm
       • Enzymes used in photosynthesis are produced here
     • Mitrochondria
       • organelle
         • Respiration takes place
     • Vacoule
       • Membrane bound sac
         • Contains molecules
           • Glucose dissolved in water
     • Cell Wall
       • Rigid box made of cellulose
   • Minerals are taken up by roots
   • Diffusion
     • Movement of particles from one area of high concentration to a lower concentration
     • Movement of O2&CO2 during photosynthesis
   • Osmosis
     • Dilute to concentrated
     • Movement of water into plant roots

3. B4.1

   • Life processes
     • Movement
       • Respiartion
         • Sensitivity
           • Growth
             • Reproduce
               • Excrete
                 • Nutrition
   • Photosynthesis
     • 6CO2+6H2O-->C6H12O6+6O2
       • Carbon dioxide+water--> glucose+oxygen
         • Glucose is converted into carbohydrates
           • Cellulose
           • Starch
             • Stored in leaves
             • Can be converted back into glucose
           • Both polymers of glucose
         • Glucose molecules break down in respiration
           • Releases energy
             • Used to power chemical reactions
     • Takes place in chloroplasts which contain chlorophyll and enzymes
       • Water, light and CO2 are taken in by chlorophylls
         • Oxygen and glucose is taken out
     • Plants trap energy from sunlight and use it to make molecules for growth
     • Can be limited by
       • Temperature
       • Carbon Dioxide
       • Light Intensity
   • Enzymes
     • Are proteins
       • Speed up chemical reactions
     • Made by cells according to instructions in genes
     • Have to be at a specific temperature and PH
       • They can denature if these are too high
         • Stop working permenently
         • Reaction does increase when temperature does
       • To work at optimum
     • Active Site
       • Lock and key model
         • Molecules have to be the correct shape to fit into the active site of an enzyme
       • Overall movement of chemicals across cell membrane
       • Used in absorption of nitrates by plant root

4. Cells

   • Animal
     • Nucleus
     • Cytoplasm
     • Cell membrane
     • Mitrochondria
       • Contains enzymes for reactions in aerobic repiration
   • Yeast
     • Nucleus
     • Cytoplasm
     • Cell membrane
     • Mitrochondria
       • Contains enzymes for reactions in aerobic repiration
     • Cell wall
   • Bacteria
     • Nucleus
     • Cytoplasm
     • Cell membrane
     • Cell wall
     • Circular DNA molecule