This document provides an overview of photosynthesis. It discusses: 1) Photosynthesis is the process by which plants capture light energy and convert it to chemical energy stored in carbohydrates. 2) The light dependent reaction uses photons of light to drive the splitting of water and production of ATP and NADPH in the chloroplast. 3) Chlorophyll and other pigments absorb different wavelengths of light, with chlorophyll a primarily absorbing red and violet light.

1. Chap. 6Chap. 6
LecLec
(Photo=light &(Photo=light & SynthesisSynthesis = put= put together)together)

2. I.I. Energy Formation:Energy Formation:
A. Autotroph v. Heterotroph
1. examples:
B. Photosynthesis is a process of
capturing & transforming light energy
into chemical energy in the form of
carbohydrates.
1. main pathway for carbon &
energy

3. 2. Energy stored in ATP molecules.
light energy
12 H2O + 6CO2 6O2 + C6H12O6 + 6H2O

4. II. Photosynthesis Part 1
A. Light dependent reaction
1.Photons: packets of energy
travel in wavelengths
2. Wavelengths: distance traveled
a. short : high energy (violet)
b. long: low energy (red)

5. B. Electromagnetic Spectrum: represents
full range of light energies & wavelengths.
ROYGBIV
1. sunlight: mixture of all visible
wavelengths. All colors reflected evenly.

6. Electromagnetic Spectrum:

7. 2. Reflection v. Absorption
a. photons not absorbed are reflected.
example:
Black object:
absorbs: ROYGBIV
reflects: none
White object:
absorbs: none
reflects: ROYGBIV

8. Absorption Spectrum for chlorophyll
a and b

9. C. Photosynthetic Pigments:
1. Pigment: photosynthetic substance
that absorbs photons.
a. chlorophyllchlorophyll=main pigment
appears green

10. 2. Pigment types:
main
a. Chlorophyll a: green
absorbs mainly red & violet
accessory pigments
b. Chlorophyll b: green-yellow
c. Carotenes: brown-orange-yellow
d. Xanthophylls: yellow-brown-purple-blue
e. Phycobilins: red-blue-green
f. Anthocyanin: red-purple

11. III. Photosynthesis in the Chloroplast:
A. Significance of plants/Photosynthesis
1. Basis of food chain
2. Clothing/Cosmetics/Industrial
3. Prevention of CO2 from
entering atmosphere.
4. Lead to evolution of larger
organisms.
5. Biodiversity