STARTER  Read 7.3 and 8.1  Look for the relationship between ATP and ADP  Look for the reactants and products of photosynthesis  Look for the relationship between the two reactions of photosynthesis 1.What are the reactants for photosynthesis? 2.What are the products of photosynthesis? 3.Name the two main stages of photosynthesis. How are the two stages related?

Starter Draw and label the chloroplast to the right. Tell me what happens in the thylakoids. What is the input and output of this reaction? Tell me what happens in the stroma. What is the input and output of this reaction?

Energy  Potential – a capacity to do work  Kinetic – energy of motion  Heat or thermal energy  Chemical – potential energy of molecules  ATP – adenosine triphosphate  ADP – adenosine diphosphate

Adenosine triphosphate (ATP)

Cellular Energy  Create as much ATP as possible  ADP + P = ATP

Photosynthesis The beginning of energy transfer.

Equation  12 H 2 O + 6CO 2  6O 2 + C 6 H 12 O 6 + 6H 2 O  Light dependent  Light independent (Calvin Cycle)

Parts of Photosynthesis  Light Reactions  Takes place in the Thylakoid Membrane  Use – Light, Water  Produce – Oxygen, NADPH, ATP  Calvin Cycle (Dark Reactions)  Takes place in the Stroma  Use – CO 2, NADPH, ATP  Produce - Sugar

Where?  Chloroplasts  Thylakoid membranes  Light dependent  Stroma  Light independent  Chlorophylls  Main pigment of photosynthesis  Absorbs all wavelengths of light except very little of yellow- green and green ones  Reflected  Carotenoids, chlorophyll a, chlorophyll b

Light-Dependent Reactions  Photosystem II  Chlorophyll traps energy from light  That energy splits water molecules into hydrogen, oxygen and electrons  e- go to the electron transfer chain  Oxygen diffuses out

Electron Transfer Chains  Membrane Proteins  Carry electrons  High energy at the beginning  NADP + - no e-  NADPH – picked up an e

Electron transfer chain  e- down the staircase  Drives ATP formation

Light-Dependent Reactions  Photosystem I  Electrons gain more energy from the sun  NADP + e-  NADPH  ADP + P  ATP  ATP & NADPH  Calvin Cycle

The Calvin Cycle  In the Stroma  Do not require direct light  Use - CO 2, NADPH, ATP  Produce – Sugar NADP+ and ADP  Cycle - continuous

The Calvin Cycle  Steps  Carbon Fixation  CO 2 goes into the cycle and is “fixed” to become sugar by Rubisco  Most important enzyme on earth  Reduction  ATP and NADPH go into cycle  Sugar is produced  Regeneration  Rubisco is regenerated to accept more CO 2