Photosynthesis Photosynthesis Overview Takes place in the chloroplast

Photosynthesis

Photosynthesis Overview Takes place in the chloroplast of a plant cell. Utilizes light energy from the sun. Purpose is to create food (glucose, sugar, C 6 H 12 O 6). Overall equation: 6 CO 2 Carbon Dioxide + 6 H 20 + light C 6 H 12 O 6 + 6 O 2 Water Energy Glucose (sugar) Oxygen

Why are plants green? Let’s talk about the Electromagnetic Spectrum

Why are plants green? Clear light contains all wavelengths (colors) of light. Pigment molecules absorb energy from light. Chlorophyll is a pigment that ABSORBS all colors of light EXCEPT green. Green light is reflected to our eye, which is why it appears green. Chlorophyll is important because it absorbs energy from the sun needed for photosynthesis.

The Chloroplast Three major parts Thylakoids: round discs that contain chlorophyll and other pigments. Granum: a stack of thylakoids. Stroma: fluid inside the chloroplast that surrounds the thylakoids.

2 Parts of Photosynthesis Light-Dependent Reactions Takes place in the thylakoids Reactants: Products: light, H 2 O energy-carrying molecules, O 2 Light-Independent Reactions (Calvin Cycle) Takes place in the stroma Reactants: Products: energy-carrying molecules, CO 2 C 6 H 12 O 6

Light Dependent Reactions 1. Water molecule is split. 2. Oxygen is released as waste. 3. The hydrogens and light energy are used to create energy carrying molecules. 4. These energy carrying molecules move to the Calvin Cycle.

Light-Independent Reactions (Calvin Cycle) 1. Carbon dioxide enters the cycle 2. Energy-carrying molecules modify the molecule many times. 3. 4. Glucose is produced. The cycle continues as long as carbon dioxide is available.

Chemosynthesis Organisms that live deep in the ocean do not receive light. Instead of photosynthesis, they utilize chemosynthesis. In chemosynthesis, glucose (sugars) are created by inorganic molecules/chemicals.

Photosynthesis Summary 6 CO 2 + 6 H 20 + light C 6 H 12 O 6 + 6 O 2 Carbon Dioxide Water Energy Glucose (sugar) Oxygen