Q.Q. 10/18/18
D ATP ADP Releases energy
Unit 2 Photosynthesis: An Overview *Add definition of Photosynthesis at the top of your notes!! Photosynthesis: the conversion of light energy to chemical energy (glucose)
Amoeba Sisters - Photosynthesis and the Teeny Tiny Pigment Pancakes
Chlorophyll & Chloroplast Chlorophyll: is a molecule in chloroplasts that absorbs light energy in the thylakoid, but reflects green light Chloroplast: are organelles in plants where photosynthesis occurs They are made up of thylakoids needed for photosynthesis
Thylakoids—tiny disk-like structures in chloroplast that contain chlorophyll Are interconnected and arranged in stacks of pancakes (granum) Chlorophyll pigments are located in thylakoid membranes Stroma- fluid-filled region outside the thylakoids
Chloroplast
Overview of Photosynthesis Photosynthesis—light energy from the sun is used to convert water and carbon dioxide (reactants) into high energy sugars and oxygen (products) Photosynthesis Reaction Light Energy
Photosynthesis has 4 main steps: Steps 1 and 2 are light-dependent reactions Steps 3 and 4 are light-independent reactions also called the Calvin Cycle (Dark Reactions)
Light-Dependent Reaction Require the presence of light & light absorbing pigments These reactions take place within the thylakoid membranes
Light-Dependent Reaction (Continued) Step 1: Chlorophyll captures sun’s energy Water (H2O) is broken down Oxygen is released Step 2: Energy carried along thylakoid membranes to molecules that carry energy to the light independent reactions.
Light-Independent Reactions or Calvin Cycle Does not require direct involvement of light These reactions use energy from light-dependent reactions to synthesize sugars The Calvin Cycle takes place in stroma of chloroplasts Step 3: CO2 is added to create larger molecules Step 4: A molecule of glucose is created Light & dark reaction animation
Factors Affecting Photosynthesis The most important factors that affect photosynthesis are: Temperature Light intensity Availability of water