B4-Bioenergetics

• Word equation for photosynthesis?

  Carbon dioxide + Water = Glucose + Oxygen
• Symbol equation for photosynthesis

  6CO2 + 6H2O = C6H12O6 + 6O2
• What type of reaction is photosynthesis?

  Endothermic
• How do plants use glucose?

  -Respiration

  -Making cellulose

  -Making amino acids

  -Stored as oils or fats

  -Stored as starch
• What are 3 limiting factors of photosynthesis?

  Light intensity

  CO2 concentration

  Temperature
• How does little light slow down photosynthesis?

  -Light provides energy for photosynthesis

  -Rate increases with light intensity but only to a certain point

  -Will stop increasing as temperature or co2 levels are the limiting factor

  -Graph flattens out
• How does little carbon dioxide slow down photosynthesis?

  -CO2 levels increases rate of photosynthesis to a point

  -Graph flattens out as the rate no longer increases
• Why does the temperature need to be just right?

  -if it’s too low the enzymes needed for photosynthesis work slowly

  -If it’s too high the enzymes are denatured so photosynthesis can’t work
• What is the inverse square law?

  Light intensity is proportional to 1/distance squared
• What is respiration?

  The process of transferring energy from glucose which goes on in every cell
• What type of reaction is respiration?

  Exothermic
• How do organisms use energy from respiration?

  -Build up larger molecules from smaller ones

  -Used to allow muscles to contract

  -Keep their body temperature steady in colder surroundings
• What is metabolism?

  Sum of all the reactions that happen in the body
• What is aerobic respiration?

  Respiration using oxygen
• Aerobic respiration equation?

  Glucose + Oxygen = carbon dioxide + Water
• What’s the equation for anaerobic respiration in muscle cells?

  Glucose = lactic acid
• What’s the equation for anaerobic respiration in yeast and plants?

  Glucose = ethanol + carbon dioxide
• What is anaerobic respiration in yeast cells called?

  Fermentation
• What is fermentation used for?

  Make bread and alcohol
• Why do muscles need respiration?

  The energy helps muscles to contract

  When you exercise you need muscles to contract more so you need more energy
• What does increased breathing rate and breath volume mean?

  Gets more oxygen into blood

  Heart rate increases to get oxygenated blood round the body faster

  Removes carbon dioxide faster
• What happens when you do vigorous exercise?

  Body can’t supply oxygen to muscles quick enough so they respire anaerobically so lactic acid builds up in muscles
• What is an oxygen debt?

  The amount of extra oxygen the body needs to react with the build up of lactic acid and remove it from cells
• How to deal with lactic acid?

  Keep breathing hard after exercise to get more oxygen into the blood to transport to the muscle cells

  Pulse and breathing rate stay high

  Blood in the muscles transports the lactic acid to the liver where it’s converted back to glucose