Photosynthesis

CLICK HERE to and scroll to watch Photosynthesis Video

Photosynthesis

The process where light energy is converted into chemical energy

Photosynthesis• Autotrophs change light

energy into chemical energy in the process of photosynthesis.

• Plants use light energy to convert water and carbon dioxide into oxygen and carbohydrates (sugars and starches)

Process of Photosynthesis• Photosynthesis is a

process used by green plants

• The is a type of autotrophic nutrition.

• Photosynthesis is carried out by chloroplasts, which contain chlorophyll

• In the chloroplasts, CO2 and H2O are used to form C6H12O6 and O2

Process of PhotosynthesisLABEL the reactants & products

below

6 CO2 + 6 H2O C6H12O6 + 6 O2

= light energy trapped in the chloroplast makes this process happen

Photosynthesis Equation

6CO2 + 6H2O C6H12O6 + 6O2

carbon water light energy sugar oxygen

dioxide (glucose)

Photosynthesis Equation

• Requirements:– 6CO2 – carbon dioxide

is absorbed from the environment

– 6H2O – water absorbed from the environment

– Energy – energy from the sun is trapped by the chlorophyll in the chloroplasts

• Products/Wastes:– C6H12O6 – organic sugar

(glucose) is stored in the plant

– 6O2 – oxygen is released as a waste product

6CO2 + 6H2O C6H12O6 + 6O2

carbon water light energy sugar oxygen

dioxide (glucose)

or water

Factors Affecting Photosynthesis

• Water or Carbon dioxide (wax prevent water loss)

• Temperature (0-35°C for enzymes)• Light intensity (min and max)

Light and Pigments

• Energy from the sun travels to Earth in the form of light of different wavelengths of the visible spectrum as different colors

• Plants gather the sun’s energy with light-absorbing molecules called pigments.

Chloroplasts• Chlorophyll in the chloroplast is

the green pigment that captures light energy to carry out photosynthesis.

• Oxygen is released through the leaves

• Organic sugars made are used by the autotroph to grow/develop or stored as carbohydrates or lipids.

CLICK HERE to scroll and watch Light Reactions

Inside Chloroplasts• Photosynthesis takes place

inside chloroplasts

• Thylakoids = saclike photosynthetic membranes containing chlorophyll and other pigments

• Grana = stacks of thylakoids

• Stroma = region (space) outside thylakoids

Light vs. Dark Reactions• Light-dependent

reactions take place within the thylakoid membranes.

• Light-independent reactions, or the Calvin cycle, take place in the stroma.

NADPH• High-energy electrons are transported

from the chlorophyll by carrier molecules• NADP+ is one carrier molecule that carries

two high-energy electrons with a hydrogen ion (H+) converting it into NADPH

• The NADPH carries the electrons produced by light absorption in chlorophyll to chemical reactions throughout the cell.

CLICK HERE to scroll and watch Glycolysis

Light-dependent Reactions

• Require LIGHT!• Use energy from

light to produce oxygen and convert ADP & NADP+ into the energy carriers ATP & NADPH

Light-independent ReactionsThe Calvin Cycle

• The Calvin cycle uses the energy from ATP & NADPH to make high-energy compounds that can store the energy longer (sugars)

• Light independent reaction = does NOT require light