Photosynthesis chap 2.9

RXN

Least useful ligth- Green light

reflected

PHOTOSYNTHESIS- overview

Thylakoid- contains chlorophyll

Light energy- trapped by chlorophyll

photosynthetic chemical

PHOTOLYSIS-Water- affected by an enzyme which splits water

hydrogen

When light energy hits chlorophyll- triggers release of electrons

Further split- H+ and an electron

Oxygen

Waste

Electrons as passed through the elctron chain- supplied by water, when split

build up of H+ (protons) in the thylo- High conc

NADP combines with a proton, and accepts an electron

forms NADPH

The H+ protons move out through a protein and help ADP combine w P to form ATP

CALVIN CYCLE CARBON FIXING

CO2 to C6H12O6

in the presence of NADPH (hydrogen dono)

And CO2

LIGHT INDEPENDANT

LIGHT DEP- Intermembranial space of thylo

LIGHT INDEP- strom

Ligth dep rxn

  1. 2 Photosystems- PS2 main PS1- backup
  1. Ligth excites chlorplasts
  1. 2electrons move down the chain

NADP+ + H+ + electron= NADPH

  1. Photolysis-To replace electrons- water splitting enz splits water into oxy and hydro- HYDRO- PROTON and ELECTRON

high proton gradient

click to edit

Chromatography- pigments in the chromatogram of spinach are identified.

Checking Rf Value

checking distance travelled by solvent

colour analysis- spectrophotometer

Rf= Dist moved by pig/dist moved by solvent

click to edit

a. autotrophs perform photosynthesis

b. carbon dioxide and water are the reactants/raw materials required for «photosynthesis»

c. light splits water molecules/causes photolysis

d. «photolysis» releases oxygen as a «waste» product

e. light energy is converted into chemical energy

f. «photosynthesis» produces organic compounds/glucose/carbohydrates

g. photosynthesis occurs in chloroplasts

h. chlorophyll «photosynthetic pigment» absorbs light

i. different pigments absorb different wavelengths «of light»

j. chlorophyll absorbs red and blue light/ends of the spectrum

k. carbon dioxide concentration/temperature/light intensity are limiting factors

PHOTOLYSIS

water is split/breaks

b. using energy from light

c. electrons «from photolysis» pass to photosystem II

d. oxygen is a «waste» product

e. hydrogen ions/protons are produced