1. Light reaction Recap 2. Calvin Cycle (dark reaction) Photosynthesis 1. Light reaction Recap 2. Calvin Cycle (dark reaction)

Talk to a Neighbor… Using the following diagram, walk your partner through the 5 steps of the light-dependent reactions

What are the reactants of the light dependent reactions? Sunlight, water, chlorophyll What are the products of the light dependent reactions? Oxygen, ATP, NADPH

ATP & NADPH that are produced in the LDR are used to power the Calvin Cycle

Part 2: Calvin Cycle aka Light-Independent reaction or Dark reaction Does NOT need light because energy from sun already captured in NADPH & ATP Occurs in stroma

Energy taken from NADPH & ATP & combined w/CO2 & H+ forming C6H12O6

NADP & ADP recycled back to light reaction Glucose can be converted by cells into lipids, proteins, nucleic acids, etc.

Calvin Cycle Video

Factors that affect the rate of photosynthesis? Amount of water & CO2 (reactants) Temperature - too high or low denatures enzymes Intensity of light

Putting it Together…

Reactants Products

Review light rxn

Reactants Diagram H2O CO2 Light Chloroplast C6H12O6 Glucose O2 Word Bank H2O Glucose Light -Dependent Chloroplast Thylakoids Grana Calvin Cycle Light O2 Stroma Reactants Products H2O CO2 Light NADP+ ADP + P Light Dependent Reaction Calvin Cycle ATP NADPH Chloroplast C6H12O6 Glucose O2 Products

Summary: Light Dependent Reaction—H2O is broken down and light energy is stored temporarily in energy carriers, ATP and NADPH Calvin Cycle—energy is transferred from ATP and NADPH to the organic compound glucose

Questions??

What are the reactants for photosynthesis? What are the products?

Where in the chloroplast do light-independent reactions occur? Stroma

Where do the ATP and NADPH used in the Calvin Cycle come from? Light Reactions

What are the 3 factors that affect the rate of photosynthesis?

Where does gas exchange occur on the leaf?

What happens to the O2 produced by the light reactions?

Cornell Summary