bioenergetics

• Give 5 ways plants can use the glucose they produce 


  1)cellular Respiration-break down the glucose to release energy

  2)make cellulose-which is used to make strong cell walls

  3)make starch-which is used to store glucose for a later time

  4)make amino acids-which are used to make proteins

  5)make lipids-these store energy as fats or oils, for later use
• Which substance is responsible for absorbing the light energy for photosynthesis

  Chlorophyll
• In which organelle (sub-cellular structure) does photosynthesis take place

  Chloroplast
• Give 3 feature of starch that make is a useful long-term storage molecule


  1)It is insoluble in water

  2)It is compact

  3)It can easily be broken down when needed
• Is photosynthesis exothermic Or endothermic

  Photosynthesis is an endothermic process, because it requires energy (from sun)
• How do plants get the water required for photosynthesis

  It diffuses from the soil Into the root hair cells, via osmosis
• in which organ does most photosynthesis take place 


  Leaf
• How do plants get the carbon dioxide required for photosynthesis

  It diffuses from the air into their leaves, via stomata
• What is the word equation for photosynthesis

  Carbon dioxide + water —light— glucose + oxygen
• Where does the energy for photosynthesis come from 


  From the sun, in the form of sunlight
• What is the symbol equation for photosynthesis

  6CO2+6H2O→C6H12O6+6O2
• Describe and explain how the rate of photosynthesis varies with temperature


  The rate initially increases with temperature because the particles have more energy and move faster, do they react more frequently

  The highest rate occurs at the optimum temperature for the enzymes

  At higher temperatures, the rate decreases as bonds holding the enzymes together begin to break, so the enzymes change shape, meaning they are no longer as complementary to the substances

  The rate falls to zero as the enzymes denature
• What is the formula that links light intensity and distance 


  Light intensity = 1 divided by distance squared (m)
• With reference to photosynthesis, what is a limiting factor 


  a limiting factor is anything that constrains (limits) the rate of reaction
• What are paraffin heaters, and why are they used in greenhouses 


  Paraffin heaters burn a fossil fuel called paraffin

  This produces carbon dioxide and heat energy, both of which help plants to grow
• What are the 3 environmental factors that affect the rate of photosynthesis 


  1)Temperature

  2)Light intensity

  3)Carbon dioxide concentration
• Why do farmers use greenhouses 


  1)Greenhouses help trap the heat energy from sunlight, and so increase the temperature

  2)They keep out pests which could otherwise damage the plants

  3)They make it easier to control the conditions, such as levels of carbon dioxide, fertiliser and water
• Give 5 examples of how cells use the energy from respiration 


  1)To combine small molecules to make larger molecules

  2)To break large molecules into smaller molecules

  3)For muscle contraction

  4)To maintain body temperature

  5)To move substances around the cell
• What is metabolism 


  The combination of all chemical reactions in an organism
• What is the word equation for anaerobic respiration in animals


  Glucose—lactic acid
• Which type of respiration releases the most energy and why 


  Aerobic respiration releases the most energy

  Anaerobic respiration doesn't break down the glucose molecule completely, so doesn't release as much energy
• Which is the symbol equation for aerobic respiration 


  C6H12O6 + 6O2 — 6CO2 + 6H2O

  all the numbers after a letter is a small number
• How is anaerobic respiration used in baking bread 


  1)When baking bread we add yeast (unicellular fungi) to the mixture

  2)As there is limited oxygen in the bread mixture, they will respire anaerobically

  3)This produces carbon dioxide which forms little bubble of gas

  4)These pockets of gas make the bread light and fluffy
• Why don’t animals always carry out aerobic respiration

  It requires oxygen, and during intense exercise there may not be enough oxygen
• What can the ethanol produced by anaerobic respiration be used for

  Making alcoholic drinks
• Is respiration an exothermic Or endothermic reaction

  Respiration is an exothermic Reaction because it involves the release Of energy
• What is respiration 


  Respiration is a chemical process that release the energy from sugar molecules such as glucose
• What is the word equation for anaerobic respiration in plants and fungi

  Glucose — ethanol + carbon dioxide
• What is the word equation for aerobic respiration

  Glucose + oxygen — carbon dioxide + water
• What is oxygen debt 


  During exercise, we often carry out some anaerobic respiration, which produces harmful lactic acid

  An oxygen debt is the amount of oxygen require to remove the latie acid and replace the body’s reserves of oxygen
• Explain how and why exercise affects the body 


  1)Exercise requires us to contract and relax our muscles

  2)Muscle contraction requires energy, which has to be released by cellular respiration

  3)Our cells prefer to carry out aerobic respiration, which requires oxygen

  4)This means that we have to pump oxygen to our muscles faster when we exercise

  5)As a result we have to increase our breathing Rate to get more oxygen into our bodies (and remove carbon dioxide), and increase our heart rate to transport that oxygen around the body
• which organ is responsible for removing lactic acid from the bloodstream

  The liver is responsible for removing lactic acid from the bloodstream
• How would you measure a persons heart rate


  Feel their pulse, and count how many beats there are in 1 minute. Pulse in neck or wrist
• How would you measure a persons breathing rate

  Watch their chest, and count how many times their chest rises and falls in 1 minute