Photosynthesis intro and light dependent Reactions

  • 10% of energy is avalible to to consumers from the last group goin up the pyrmaid

  • Leaves preform mosth of Photo sythesis

  • Leaves increase surface area to absorbe more sunlight and make photosythiesis more effcient

  • Chloroplast have 3 Membranes:

    • Outer, inner, thylakoid membrane
    • Chlorophyll is what makes them green and is embededd in the thylakoid membrane

  • Chlorophyll absorbs light and refects green

    • Chlorophyll is the first molecule to break down when leaves die which is why they turn brown in the fall
    • different forms of chlorophyll absorb differnt colors

  • A photosytem is a custer of pigment molecules bpund to prtiens along wwith a primare electron acceptor.

    • Photosytem II absorbs light at a wavelength of 680nm
    • Absorbs the energy in a photon exciting an electron to a hight energy level
    • Now One electron short
    • Replaced by Photolysis- the splittting of water using light
    • O2 is realsed
    • Excited elcetron travels down the electron transport chain

  • the elctron transport chain is made of increasingly electron negative cytochromes

  • This creates a conectration gradent of protons

    • Photosystem I absorbs ligh at 700nm
    • absorbes lightenergy exciting Its electrons to a higher energy level
    • the electrons lost is replaced by the the elect tron from PhotosystemII
    • The excited elecron from Photosystem I travels down another ETC losing energy
    • Reduces NADP+ to NADPH (an electron cariere)