Standard 4- Metabolism: (Photosynthesis)

You will be able to: Identify the products and reactants in photosynthesis and cellular respiration. Illustrate how photosynthesis and cellular respiration form a cycle (one process uses the products of the other) Differentiate between aerobic and anaerobic respiration

Photosynthesis Carbon Dioxide

Photosynthesis Equation You will need to know that some things are needed for the reaction to occur- reactants, and some things are products of the reaction, the outcome. 6 CO2 + 6 H20 -----> C6H12O6 + 6 O2 Reactants Products

Pigments In addition to water, carbon dioxide, and light energy, photosynthesis requires Pigments Chlorophyll is the primary light-absorbing pigment in autotrophs Chlorophyll is found inside chloroplasts

Inside A Chloroplast

Structure of the Chloroplast Chloroplast is an organelle in plant cells that have double membranes The outer membrane is smooth The inner membrane forms stacks of connected sacs called thylakoids A thylakoid stack is called the granum (grana-plural) Gel-like material around grana is called stroma

Photosynthesis Inside the Chloroplast

First Step: Light Dependent Reactions Chloroplasts absorb light energy to make temporary energy molecules: NADPH and ATP Occurs in the chlorophyll in the thylakoid membranes Uses light energy Produces Oxygen from water Converts ADP to ATP (energy!) Also adds electrons to an energy carrier to make NADPH

Light Dependent Reaction

Light Dependent Reaction

Light Dependent Reaction Summary Reactants (what we used): H2O (Water) Light Energy (Sun) Products (what we gained): ATP (energy) NADPH (electron carrier) 02 (Oxygen) (We are halfway through the Photosynthesis Cycle.)

Light Independent Reaction (AKA:The Calvin Cycle orThe Dark Reaction) ATP & NADPH from the light reaction is used to give energy to this reaction. It powers the process that takes C02 from the air to make glucose. This reaction occurs in the stroma.

Light Independent Reaction (Calvin Cycle) Summary Reactants (What we used): ATP and NADPH (forms of energy) C02 (Carbon Dioxide) Products (What we gained): Sugars (glucose) (We have now completed a full cycle of Photosynthesis!)

The overall photosynthesis process: CO2 + H2O + light energy ---> C6H12O6 + O2 Reactants (what we used): H2O (Water) Light Energy (Sun) Products (what we gained): ATP (energy) NADPH (electron carrier) 02 (Oxygen) Reactants (What we used): ATP and NADPH (forms of energy) C02 (Carbon Dioxide) Products (What we gained): Sugars (glucose)

Factors Affecting the Rate of Photosynthesis How do you think these factors would affect how fast or slow photosynthesis occurs? Amount of available water Temperature Amount of available light energy

Let’s Review! What are two reactions during photosynthesis? What are the reactants and products in each one? Where do they occur? What are the factors that affect the rate of photosynthesis?