Photosynthesis

Comparing Photosynthesis & Respiration PhotosynthesisCellular Respiration FunctionEnergy StorageEnergy Release LocationChloroplastsMitochondria ReactantsCO 2 and H 2 OC 6 H 12 O 6 and O 2 ProductsC 6 H 12 O 6 and O 2 CO 2 and H 2 O Equation6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2 C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O

Mitochondrion and Chloroplast structure

Photosynthesis overview Process of storing energy in sugar molecules from the energy initially in the sun (radiant energy) 1 st step: Capture radiant energy and use it to generate our “energy currency” 2nd step: Use “energy currency” to convert CO 2 to glucose Oxygen is released as a byproduct Happens in the chloroplast

WHY ARE PLANTS GREEN? It has to do with sunlight! Sunlight is a form of electromagnetic energy, which travels in waves.

Different wavelengths of visible light are seen by the human eye as different colors. WHY ARE PLANTS GREEN? Gamma rays X-raysUVInfrared Micro- waves Radio waves Visible light Wavelength (nm)

Sunlight minus absorbed wavelengths or colors equals the apparent color of an object. The feathers of male cardinals are loaded with carotenoid pigments. These pigments absorb some wavelengths of light and reflect others. Reflected light

Chloroplasts contain several pigments Chloroplast Pigments Pigments are materials that absorb particular wavelengths of light and reflect others  Chlorophyll a: absorbs mainly violet and red light the best  Chlorophyll b: absorbs blue and orange light the best  Carotenoids: absorbs blue and green best * When chlorophyll absorbs light, energy is transferred to electrons and “boosts” them to a higher state. Figure 7.7

Different pigments absorb light differently

Photosystems: Clusters of pigments in thylakoid membrane Photosystem II -Traps light energy and transfers the light-excited electrons to an electron transport chain. -Those excited electrons are replaced by splitting a molecule of water, which releases oxygen. -The electron transport chain releases energy, which is used to make ATP Photosystem I -Produces NADPH by transferring excited electrons and hydrogen ions to NADP+.

Light Reactions Photosystem I and Photosystem II In the light reactions, electron transport chains generate ATP, NADPH, & O 2SUMMARY: In the light reactions, electron transport chains generate ATP, NADPH, & O 2 –Two connected photosystems collect photons of light and transfer the energy to chlorophyll electrons –The excited electrons are passed from the primary electron acceptor to electron transport chains –The light reactions convert light energy to the chemical energy of ATP and NADPH

The Light Dependent Reactions

The production of ATP in photosynthesis Thylakoid compartment (high H + ) Thylakoid membrane Stroma (low H + ) Light Antenna molecules Light ELECTRON TRANSPORT CHAIN PHOTOSYSTEM IIPHOTOSYSTEM IATP SYNTHASE

Calvin Cycle Called a cycle because the starting material, RuBP, is regenerated. Uses carbon from carbon dioxide, the energy from ATP, and high energy electrons and hydrogen ions from NADPH to make a small sugar named G3P. The plant uses G3P to make glucose and other organic molecules. Overall input: CO 2, ATP, NADPH Overall output: Glucose

Review: Photosynthesis uses light energy to make food molecules Light Chloroplast Photosystem II Electron transport chains Photosystem I CALVIN CYCLE Stroma Electrons LIGHT REACTIONSCALVIN CYCLE Cellular respiration Cellulose Starch Other organic compounds Light reactions use water and produce oxygen. The Calvin Cycle uses ATP and NADPH created in the the light reactions to convert carbon dioxide to glucose.

Fill out the following chart to compare Photosynthesis and Cellular Respiration PhotosynthesisCellular Respiration Function Location Reactants Products Equation

Photosynthesis – Cellular Respiration comparison PhotosynthesisCellular Respiration FunctionEnergy captureEnergy release LocationChloroplastsMitochondria ReactantsCO 2 and H 2 OC 6 H 12 O 6 and O 2 ProductsC 6 H 12 O 6 and O 2 CO 2 and H 2 O Equation 6CO 2 + 6H 2 O light > C 6 H 12 O 6 + 6O 2 6O 2 + C 6 H 12 O 6  6CO 2 +6H 2 O + energy