Bioengernetics

• Photosynthesis - endothermic reaction
• carbon dioxide + water -----> oxygen + glucose

  $6CO_2\ +$$\ 6H_2O\ \rightarrow\ 6O_2\ +$$\ C_6H_{12}O_6$

  in the $\rightarrow$ = light energy and chlorophyll
• chlorophyll


  absorbs sunlight

  green pigment in chloroplasts
• uses of glucose in plants


  plants make what they need from glucose

  1. glucose = sugar - sugar dissolves in water (the more sugar, the thicker the liquid) - if a plant has too much glucose it gets flaccid - not enough water as it tries to balance out the concentration
  2. photosynthesis produces glucose the plant use for respiration
  3. plants also store glucose as insoluble starch - this means plant can convert it back into glucose if little photosynthesis is happening
• uses of glucose in plant

  1. plants use glucose to make cellulose to strengthen their cell wall = this makes the leaves, stems and roots stronger
  2. glucose is used to make fats and oil for the plant - you can find oils in seeds, fruit and nuts : such as olive oil, sunflower and peanut oil - these oils are used to store chemical energy for the plant
  3. glucose is used to help produce protein in plants - plants use glucose to build amino acids - to do this plants need the mineral nitrate
• testing a leaf for starch


  method;

  1. take one leaf from a plant in the light and one from a plant in the dark
  2. Place the leaves in a beaker half filled with boiling water
  3. after a few seconds, remove the leaves from the water and place in a boiling tube $\frac{1}{4}$ full of ethanol
  4. after about 5 minutes, check the colour of the leaf, if it has lost its colour, remove the leaf
  5. Place on a white tile and add a few drops of iodine
• testing a leaf for starch - results


  leaf in light - turned black - has starch

  leaf in dark - didn't turn black - no starch
• pond weed - RQP


  method;

  1. set up a test tube rack containing a boiling tube at a distance 10cm away from the light source
  2. fill the boiling tube with the sodium hydrogen carbonate solution
  3. put a piece of pond weed into the boiling tube with the cut end at the top - gently push the pond weed down
  4. leave in the boiling tube for 5 minutes (to acclimatise it)
  5. start the stop watch and count the number of bubbles produced in one minute - write this down
  6. move the test tube rack 10 more cm away from the light source - repeat steps 4-5
  7. repeat whole thing 2 more times - mean
• pond weed RQP - results


  further away from the light source - less amount of bubbles (carbon dioxide)
• rate of photosynthesis


  number of bubbles produced per minute
• inverse square law


  when the lamp is moved away from the pondweed the amount of light decreases

  this means the distance and light intensity are inversely proportional to each other

  light intensity actually decrease in proportion to the square of the distance

  $light\ intensity\ =$$\ \frac{1}{d^2}$
• limiting factors of photosynthesis - light intensity


  other factors after the graph plateaus - chlorophyll, temperature, $H_2O,\ CO_2\$

  before the graph plateaus - limiting factors = light intensity

  A) light intensity

  B) other factors

  
• limiting factors of photosynthesis - carbon dioxide


  other factors after the graph plateaus - chlorophyll, light intensity, temperature,$H_2O$

  before the graph plateaus - carbon dioxide

  A) CO2 limiting factor

  B) other factors

  
• limiting factors of photosynthesis - temperature


  before the peak of the graph - limiting factor = temperature

  after the peak (optimum temperature) - limiting factor = denatured enzyme - no photosynthesis

  photosynthesis = controlled by temperature - controlled by enzymes

  A) temperature = limiting factor

  B) after this - denatured enzymes

  
• ideal conditions for photosynthesis


  greenhouses -

  trap in the sun's heat - temperature isn't a limiting factor (in winter = heaters)(in summer, if too hot = shades + ventilation)

  artificial light

  farmers can increase the $CO_2$ levels - paraffin heaters

  keep plants enclosed - less pests and diseases

  farmers can add fertilisers to provide minerals

  cost money - electricity bills
• respiration


  the process of transferring energy from glucose, which goes into every cell

  it takes place in mitochondria

  exothermic - transfers energy to the environment

  releases energy

  two types = aerobic, anaerobic
• the bodies role in respiration

  • the blood is delivery system
  • the heart pumps the blood to all cells
  • breathing maintains the concentration gradient for diffusion og gases
  • digestion supplies glucose
  • glycogen is a store of glucose
• living things need energy 


  plants -

  • build large molecules from smaller one - make amino acids from sugars, nitrates and other nutrients - combine amino acids to make proteins

  animals -

  • animals contract their muscles to move
  • build large molecules from smaller ones - make proteins, fats, carbohydrates - builds new tissue
  • mammals and birds keep a constant body temperature
• gases - inhale/exhale


  oxygen - 21% in - 16% out

  carbon dioxide - 0.03% in - 3% out

  nitrogen - 78% in - 78% out

  water vapour - small amount in - significantly moist out
• Aerobic respiration


  glucose + oxygen -> carbon dioxide + water

  $C_6H_{12}O_6\ +$$\ 6O_2\ \rightarrow\ 6CO_2\ +$$\ 6H_2O$
• aerobic respiration 


  needs oxygen

  happen in cells when glucose reacts with oxygen

  most efficient way to transfer to transfer energy from glucose

  exothermic

  aerobic respiration is the release of energy from the food you've eaten - like burning it requires oxygen and produces $CO_2$ and $H_2O$ aa waste products
• aerobic respiration - use of energy


  muscles contraction

  maintaining body temperature

  building up larger molecules

  building up sugars (plants only)
• anaerobic respiration 


  glucose -> lactic acid

  $C_6H_{12}O_6\ \rightarrow\ 2C_3H_6O_3$
• anaerobic respiration


  without oxygen

  the incomplete breakdown (oxidisation) of glucose which makes lactic acid

  cytoplasm of cells

  less efficient

  only used in emergencies
• oxygen debt


  after you body has done anaerobic respiration, you have oxygen debt

  this is the amount of oxygen your body needs to 'repay' as your heart and lungs couldn't keep up with demand for oxygen

  you breathe heavily to keep getting oxygen into your blood
• plants and yeast


  plants do not produce lactic acid, they produce $CO_2$ and ethanol instead

  glucose -> ethanol + $CO_2$
• fermentation


  anaerobic respiration in yeast cells is called fermentation

  used to make bread and alcoholic drinks
• metabolism


  the sum of all the reactions happening in a cells an organism, in which molecules are made or broken down
• reaction in metabolism


  conversion of glucose to starch, glycogen and cellulose

  making lipids - from glycerol and 3 fatty acids

  making proteins - from amino acids and proteins

  respiration

  in plants -> glucose and nitrates to make proteins (first, amino acids)
• formation of molecules


  glucose converts into glycogen which is insoluble

  lipids are formed by combing fatty acids and glycerol

  amino acids are joined to form proteins

  urea -> broken down amino acids
• carbohydrates


  carbon

  hydrogen

  oxygen
• protein


  amino acids;

  carbon

  hydrogen

  oxygen

  nitrogen
• lipids


  carbon

  hydrogen

  oxygen
• factors that effect metabolism


  people have different metabolic rates because...

  • the proportion of muscles to fat
  • amounts of activity
  • genetics
• exercise - effects on the body


  more energy needs to be released-

  • more respiration
  • increased removal of waste products
• heart rate effects on exercise


  heart rate increases

  pumps blood faster to muscles

  more oxygen and glucose to cells
• volume of blood pumped in each heart beat effects on exercise


  volume increases

  pumps more blood per beat

  more oxygen and glucose per beat
• breathing rate effects on exercise


  increases

  faster intake of oxygen

  faster excretion of carbon dioxide
• breathing rate effect on exercise


  increases

  more air in every breathe

  more oxygen in body per breath
• glycogen levels in muscles effects on exercise


  decreases

  glycogen is broken down into glucose