PHOTOSYNTHESIS USES LIGHT ENERGY TO MAKE FOOD

PHOTOSYNTHESIS

Process that converts light energy to _________________

Occurs in _________________ of green plants

CHLOROPLASTS

Most are located in leaves— major site of photosynthesis

Contain pigment called __________________________

Gives chloroplasts their green color

CHLOROPLAST STRUCTURE

Enclosed by two membranes

Inner membrane encloses a thick fluid called stroma

Disk-shaped sacs called thylakoids are suspended in stroma

___________________: stack of thylakoids

CHLOROPLAST STRUCTURE

PHOTOSYNTHESIS EQUATION

sunlight

6 CO2 + 6 H2O C6H12O6 + 6 O2 sunlight

6 carbon dioxide + 6 water glucose + 6 oxygen

Occurs in two main stages:

1. light reactions

2. __________________________

CHLOROPLAST STRUCTURE ORGANIZES PHOTOSYNTHESIS

Reactions take place in different areas of chloroplast:

Light reactions occur in thylakoid membranes

Calvin cycle occurs in the stroma

PHOTOSYNTHESIS and CELLULAR RESPIRATION

Photosynthesis Equation: sunlight

6CO2 + 6 H2O C6H12O6 + 6 O2

sunlight

6 Carbon Dioxide + 6 Water Glucose + 6 Oxygen

Cellular Respiration Equation: C6H12O6 + 6 O2 6 CO2 + 6 H2O + ATP

Glucose + 6 Oxygen 6 Carbon Dioxide + 6 Water

LIGHT REACTIONSConvert energy in sunlight to chemical energy in steps

Chlorophyll molecules capture light energy (units called photons)

Captured energy is used to split water molecules photolysis

H2O O2 and H+ ions produced

LIGHT REACTIONSO2 escapes from leaf as _____________________________

H+ bonds to NADP+ (electron carrier molecule) forming NADPH

NADPH moves to stroma

ATP is produced by light energy

THE CALVIN CYCLE

____________ from light reactions provides energy to make glucose

THE CALVIN CYCLECalvin cycle reactions are also called the light-independent or dark reactions (can occur without direct light)

Cannot continue indefinitely without two inputs supplied by light reactions:

1. ATP

2. NADPH

THE LIGHT REACTIONS

CONVERT LIGHT ENERGY TO

CHEMICAL ENERGY

LIGHT ENERGY & PIGMENTS

________________________: part of the electromagnetic spectrum our eyes detect as different colors

ROY G BIV

Pigments: chemicals that absorb, transmit, or reflect different wavelengths of light

What you need to know about the light reactions

Occur on thylakoid membranes

Get energy from photons of light

Reactants: H2O, light

End products: O2, NADPH, ATP

What you need to know about the light reactions

Destination of end products:

ATP and NADPH go to stroma (Calvin cycle)

O2 leaves as waste product

THE CALVIN CYCLE (Light Independent)

MAKES SUGAR FROM CARBON DIOXIDE

What you need to know about the Calvin cycle

What are the reactants?

1. RuBP

2. NADPH

3. ATP

4. ____________

CALVIN CYCLEWhat are the end products?

- 3-carbon sugar G3P used by

plant cells to produce more

complex carbohydrates

- glucose

- ______________________

- cellulose

CALVIN CYCLEWhere does energy for Calvin cycle come from?

- ATP produced in light reactions

Where does the Calvin cycle occur?

- stroma of chloroplast

SUMMARY OF PHOTOSYNTHESIS

SUMMARY OF PHOTOSYNTHESIS

6 CO2 + 6 H2O C6H12O6 + 6 O2

LIGHT REACTIONS:

Occur on thylakoid membranes

Convert light energy to chemical energy of ATP

Use reactant H2O from the equation and releases product O2

SUMMARY OF PHOTOSYNTHESIS

CALVIN CYCLE:

Occurs in stroma of chloroplast

Uses ATP and NADPH from light reactions

Uses the reactant CO2 from the equation and produces _________