Photosynthesis

Photosynthesis

• Process by which chlorophyll- bearing cells covert light energy into chemical energy

• chemical energy- contained in bonds in simple sugar

• 6CO₂ + 12H₂O + Light Energy → C₆H₁₂O₆ + 6H₂O

Chloroplast structure

• inner membrane, stroma (fluid), outer membrane, thylakoid disc , granum stack of discs

• Stomata- allows for gas exchange of water, carbon, and oxygen vapor

• Note: Chloroplasts are located in the Mesophyll cells of plants

Oxidation

• loss of electrons from molecule

• loss of energy

• loss of hydrogen atoms

• Example: C₆H₁₂O₆ →6O₂ + 6H₂O+38ATP

• arrow is cell respiration

Reduction

• Gain of electrons

• gain of energy

• gain of hydrogen atoms

Phosphorylation

• addition of a phosphate group to a molecule

• gives the molecule energy

• ADP+P; ATP

Light Energy

• Form of electromagnetic radiation from the sun

• light weights: Photons

• Plant Capture light energy in the visible light spectrum

• 380 nm- 750 nm

• Plants absorb: blue + red

• Reflect: Green + yellow

Plant Pigments

• located in the chloroplasts

• function in absorbing visible light

Types:

1. Chlorophylls

• appear green (reflect green +yellow)

• two: Chlorophyll A

• Chlorophyll B

• both absorb: blue, indigo, violet, red + orange

2. Caratenoids- reflect yellow + orange

ex: carotene- orange xanthophyll-yellow