photosynthesis

• Photosynthesis


  Uses sunlight, water, and carbon dioxide to produce glucose and oxygen

  
• Photosynthesis


  • Converts sunlight energy into chemical energy

  
• Chloroplast


  Where photosynthesis occurs in plants

  
• Chlorophyll


  Green pigment in chloroplasts that gives plants their green colouring
• Uses of glucose produced in photosynthesis


  • Immediate source of energy
  • Stored as starch for later conversion to glucose
  • Chemical starting point for synthesis of complex compounds like cellulose and proteins

  
• Chloroplast structure


  • Double membrane structure
  • Stroma - fluid matrix used in light-independent stage
  • Thylakoid membranes - flat hollow discs containing chlorophyll used in light-dependent stage
  • Grana - stacks of thylakoid membranes
  • Thylakoid lamella - flat membrane sheets in-between each grana
• Stages of photosynthesis


  1. Light-dependent stage - occurs in thylakoid membrane, converts captured sunlight energy into chemical energy of loaded coenzymes

  2. Light-independent stage - occurs in stroma, assembles simple inorganic carbon dioxide molecules into more complex organic glucose molecules

  
• Light-dependent stage


  Inputs: Light, water (H2O), NADP+, ADP and Pi

  Outputs: Oxygen (O2), H+ protons, electrons, NADPH, ATP

  Light energy absorbed through chlorophyll splits water, produces oxygen, loads ATP and NADPH for use in light-independent stage

  
• Light-independent stage


  Inputs: Carbon dioxide, NADPH, ATP

  Outputs: Glucose, NADP+, ADP + Pi, water (H20)

  Does not require light, uses ATP and NADPH from light-dependent stage to make glucose via Calvin cycle, releases water as waste

  
• Rubisco is the main enzyme in the light-independent stage, vital for carbon fixation

  
• Water is present as the main medium for glucose production in photosynthesis

  
• LIGHT-DEPENDENT STAGE (D)

  • Inputs: Light, water (H2O), NADP+, ADP and Pi 
  • Outputs: Oxygen (O2), H+ protons, electrons, NADPH, ATP
• LIGHT-INDEPENDENT STAGE (I)

  • Inputs: Carbon dioxide, NADPH, ATP 
  • Outputs: Glucose, NADP+, ADP + Pi, water (H20) 
• location of light dependent stage = thylakoid membrane
• location of light independent stage = stroma
• Stages in Cellular respiration (Aerobic) 

  Glycolysis 

  • Cytosol 
  • Glucose is converted into pyruvate 
  • 2 ATP produced 

  Link reaction 

  • Fluid matrix of mitochondria 
  • Pyruvate is converted into acetyl through coenzyme A 
  • No ATP produced 

  Krebs cycle 

  • Fluid matrix of mitochondria 
  • Pyruvate is converted to carbon dioxide 
  • 2 ATP produced 

  Electron transport chain 

  • Cristae (Inner membrane of mitochondria) 
  • Hydrogen combines with oxygen to produce water 
  • 26-28 ATP produced 
• LACTIC ACID FERMENTATION

  • Inputs: Glucose, NAD+ (2), ADP + Pi (2) 
  • Outputs: Lactic acid, NAD+ (2), ATP (2) 

   
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  YEAST FERMENTATION - ALCHOHOLIC

  • Inputs: Glucose, NAD+ (2), ADP + Pi (2) 
  • Outputs: Ethanol, CO2, NAD+ (2), ATP (2)
• factors that affect photosynthesis = light availability, water availability, temperature, C02 concentration