photosynthesis

• Photosynthesis has a light dependent phase and a light independent phase (also known as the Calvin cycle)
• The light dependent phase takes place in the thylakoids of the chloroplast
• The light independent phase (Calvin cycle) takes place in the stroma of the chloroplast
• Photosynthesis equation


  Balanced equation with numbers in front of reactants and products
• Components required for photosynthesis

  • Carbon dioxide
  • Water
  • Sunlight
  • Chlorophyll
• Products of photosynthesis


  • Glucose
  • Oxygen
• Light dependent phase


  1. Sunlight absorbed by chlorophyll

  2. Water split into hydrogen and oxygen

  3. Hydrogen attached to NADP to form NADPH

  4. Electron used to phosphorylate ADP to ATP
• NADPH


  Carries hydrogen to light independent phase
• ATP


  Energy carrier used in light independent phase
• Light independent phase (Calvin cycle)

  1. RuBP (5 carbon) combines with CO2

  2. Unstable 6 carbon compound breaks down into 2 PGA (3 carbon)

  3. PGA converted to PGAL (3 carbon) using ATP and NADPH

  4. Some PGAL becomes glucose, some reforms RuBP to repeat cycle
• Oxygen is released as a byproduct of the light dependent phase
• ADP and phosphate from ATP, and NADP from NADPH, are recycled back to the light dependent phase
• Key terminology


  • Photolysis
  • Photophosphorylation
  • RuBP
  • PGA
  • PGAL
• Chloroplast


  The organelle responsible for photosynthesis
• Chloroplast


  • Has an outer membrane
  • Has an inner membrane
  • Contains thylakoids
  • Contains stroma
• Thylakoid


  Coin-like structures stacked to form a granum
• Granum


  A stack of thylakoids
• Grana


  The plural of granum
• Intergranal lamellae


  The connections between thylakoids
• Chloroplasts are structured to provide maximum surface area for photosynthetic reactions
• Photosynthesis


  1. Takes in water and carbon dioxide

  2. Uses sunlight and chlorophyll

  3. Produces glucose and oxygen
• Products of photosynthesis


  Glucose and oxygen
• Reactants of photosynthesis


  Water and carbon dioxide
• Photosynthesis


  Can be reversed by cellular respiration
• Photosynthesis occurs in two stages: the light-dependent reactions in the thylakoids, and the light-independent Calvin cycle in the stroma
• Photosynthesis and cellular respiration are complementary processes
• Bryophytes are the simplest plants
• Bryophytes


  • Do not have vascular tissue (xylem and phloem)
  • Do not have a cuticle to prevent drying out
  • Rely on water for reproduction
  • Do not have true roots, stems or leaves
• Rhizoids


  Structures that anchor bryophytes to surfaces, also found in fungi
• Alternation of generations


  Plants exist in two generations - sporophyte and gametophyte
• Meiosis


  Process of halving the chromosome number to produce gametes
• Mitosis


  Cell division to produce more of the same cells without changing the chromosome number
• Haploid


  Having half the normal chromosome number
• Diploid


  Having the full, normal chromosome number
• Bryophyte life cycle


  1. Spore released

  2. Protonema develops

  3. Gametophyte forms

  4. Male and female gametophytes produce gametes

  5. Fertilisation occurs

  6. Zygote develops into sporophyte

  7. Sporophyte produces spores
• Sporangium


  Structure where spores are produced
• Antheridium


  Male reproductive structure producing sperm
• Archegonium


  Female reproductive structure containing egg cells
• Zygote


  Cell formed by the fusion of a sperm and egg cell
• Bryophytes are unusual in that the sporophyte generation grows out of the gametophyte generation