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 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 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 REACTIONS Convert 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 REACTIONS O2 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 CYCLE Calvin 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 CYCLE What are the end products? - 3-carbon sugar G3P  used by plant cells to produce more complex carbohydrates - glucose - ______________________ - cellulose

CALVIN CYCLE Where 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 _________