B4 - The Processes of Life

B4 - The Processes of Life

1. Enzymes

   • PROTEINS that SPEED UP a chemical reaction
     • instructions for making enzymes are found in a cells gene
   • chemical reactions - either split apart or join together
     • substrate is a molecule changed in a reaction
       • every enzyme has an active site - substrate joins to enzyme
         • enzymes only speed up one reaction
           • substrate has to be correct shape to fit into active site
             • called LOCK AND KEY method
   • need the right temperature and pH
     • specific constant temp to work at OPTIMUM
       • high temp increases rate at first
         • too hot = bonds break // enzymes change shape of active site // substrate doesn't fit // enzyme doesn't work // = DENATURED

2. Respiration

   • RESPIRATION is series of chemical reactions that RELEASES ENERGY by breaking down FOOD MOLECULES.
     • movement - muscle contraction
     • active transport - move substances in or out of cells
     • synthesis of large molecules
       • glucose joined to make starch and cellulose in plant cells
       • animal & plant cells glucose and nitrogen joined to make amino acids - joined together to make proteins
     • there are two types
       • Aerobic - WITH OXYGEN
         • Releases more energy per glucose molecule
           • takes place in animal and plant cells and microorganisms
             • Glucose + Oxygen = Carbon Dioxide + Water (+ Energy Released)
               • C6 H12 O6 + 6O2 = 6CO2 + 6H2O
       • Anaerobic - WITHOUT OXYGEN
         • Humans Cells // Vigorous exercise, body can't supply enough oxygen to muscle cells for aerobic respiration
           • Plant Cells // Soil becomes waterlogged, no oxygen available for roots
             • Bacterial Cells // Under skin through puncture skin, little oxygen.
               • Animal & Plant Cells can produce lactic acid // Glucose = Lactic Acid (+Energy Released)
         • Plant Cells and Microorganisms produce ehtanol and carbon dioxide - Glucose = Ethanol + Carbon Dioxide (+ Energy Released)
         • Fermentation - microorganisms break down sugars
           • Biogas
             • ferment plant&animal waste - contains carbs
               • gas produced mainly methane and carbon dioxide
           • Bread
             • made using YEAST
               • ferment carbs in flour & release CO2 - bread rise
           • Alcohol
             • YEAST ferment SUGAR to form ALCOHOL

3. photosynthesis

   • series of chemical reactions that USES ENERGY from SUNLIGHT to PRODUCE FOOD
     • happens in green parts of plants & some microorganisms
       • chlorophyll is needed
         • green substance absorb sunlight, allows energy to convert CO2 and H20 into glucose (C6H12O6)
           • Carbon Dioxide + Water = Glucose + Oxygen
             • 6CO2 + 6H2O = C6H12O6 = 6O2
     • glucose
       • respiration
       • chemicals for growth
       • stored as starch

4. Rate of Photosynthesis

   • amount of light
   • amount of CO2
   • temperature

5. Investigating Photosyntheis

   • transect
   • light meter
   • quadrat
   • identification key

6. Diffusion

   • the passive overall movement of particles from a region of their HIGHER CONCENTRATION to a region of their LOWER CONCENTRATION

7. Osmosis

   • overall movement of water from a dilute to a MORE CONCENTRATED solution through a partially permeable membrane

8. Active Transport

   • overall movement of chemicals across a cell membrane from a region of LOWER CONCENTRATION to a region of HIGHER CONCENTRATION using ENERGY released by respiration