Photosynthesis Intro & Chloroplast Structure

Photosynthesis: transforms light energy (from the sun) into chemical energy (glucose & other organic molecules)

  • Energy cannot be created or destroyed, only transformed

Photosynthesis Equation: 6CO2 + 12H2O —> (light/chlorophyll) C6H12O6 + 6O2 + 6H2O

Autotrophs: organisms that can produce their own chemical energy (organic compounds)

  • AKA producers

  • they supply chemical energy to the entire ecosystem

Photoautotrophs: use light energy to do so (photosynthesis)

  • Heterotrophs: cannot make their own chem. energy

  • Chemoautotrophs: use chemical energy to make their energy

  • EX: of Photosynthetic Organisms:

    • Plants

    • Algae

    • Cyanobacteria (blue/green algae, but not really algae)

  • Photosynthesis occurs in LEAVES —> specifically mesophyll cells

    • have large # of chloroplasts

Chloroplast Structure:

  • double membrane was formed during Endosymbiosis (prokaryotic cell engulfs another prokaryote)

    • outer/inner membrane

Thykaloid: flattened, membrane-bound sacs —> high SA: V ratio

  • surrounded by thylakoid membrane

Thylakoid membrane: surrounds thylakoids

Thylakoid space: inner region of the thylakoid

  • light-dependent reaction

Stroma: fluid-filled space between the inner membrane & the thylakoid membrane

  • function: location where the Calvin Cycle occurs —> contains enzymes & materials for the Calvin Cycle

  • light-independent reaction

3 Spaces w/in a Chloroplast:

  • Intermembrane Space: between outer & inner membrane

  • Stroma: between inner membrane & thylakoid membrane

  • Thylakoid Space: w/in the thylakoid membrane

    • lamellae connect the grana together to make the thylakoid space continuous