Bioenergetics

• Photosynthesis

  carbon dioxide + water —> glucose + oxygen

  6CO + H2O —> C6H12O6 + O2

  -process where plants make there own food

  -endo-thermic

  -requires light energy absorbed by chlorophyll
• Biosynthesis

  -some glucose from photosynthesis is used for respiration

  -if not used for that it’s used for cellulose, starch, proteins or lipids
• Factors on photo synthesis

  Light intensity = increase light there is more photosynthesis

  carbon dioxide = concentration increase there is more photosynthesis but at some point may become limiting

  temperature = chemical reaction is controlled by enzymes at optimum temp there is more photosynthesis but to high will denature enzyme

  chlorophyll = more will increase photosynthesis
• Aerobic respiration

  -requires oxygen to break down glucose to release energy

  -glucose and oxygen react to produce carbon dioxide water and energy
• Anaerobic respiration

  -doesn’t require oxygen

  -glucose converts into lactic acid and energy

  -plants like yeast respire anaerobically producing ethanol and carbon dioxide
• exercise

  -muscles need energy as breathing rate increases to supply more blood and heart rate increases to give muscles more oxygen

  -if not enough oxygen muscles will respire anaerobically, contract but less efficiently

  -long vigorous exercise = lactic acid build up + glycogen reserves become low as it’s used up

  -lactic acid build up causes oxygen debt as liver needs to convert lactic acid back to glucose
• Metabolism

  -all chemical reactions in an organisms body

  -controlled by enzymes
• Plant metabolism

  -glucose can become starch, cellulose, lipids, amino acids (proteins) and then used in respiration

  -can be reversed with these being broken down into glucose
• animal metabolism

  -glucose can become lipids (fatty acids + glycerol) and glycogen then used for respiration, as well as amino acids becoming proteins

  -can be inverse and amino acids removed as urea