Energy and Photosynthesis

Energy Ability to do work Adenosine Triphosphate – stores and releases energy, energy carrier

ADP + P -> ATP ATP – stores energy To release energy – remove a phosphate group = ADP

Heterotrophs versus Autotrophs Heterotrophs - Must consume food to obtain energy Autotrophs - can make their own food using sunlight

Light Absorption Red, Orange, Yellow, Green, Blue, Indigo, Violet Pigments – absorb wavelengths of light Chlorophyll A and B – primarily absorb all but Green, why leaves look green

Chloroplasts

High Energy Electrons High Energy Electron Carrier = NADP+ Carrier needed to move high energy electrons across thylakoid membrane Accepts 2 high energy electrons along with a hydrogen ion Becomes NADPH NADP+ + 2 e- + H+ = NADPH Remember the energy carrier… ATP

Overview of Photosynthesis Write the chemical formula of photosynthesis 6H2O + 6CO2 + Light energy -> C6H12O6 + 6O2 Water + carbon dioxide + sun yields sugar (glucose) and oxygen Reactants: water, carbon dioxide and sunlight Products: glucose and oxygen 3 compounds made from the sugar produced in photosynthesis includes complex carbohydrates, proteins and lipids.

Light Dependent Stage of Photosynthesis Location: Thylakoid (membrane and space) Steps Light is absorbed Water is broken apart, Oxygen is produced Produces ATP and NADPH to be used in Calvin cycle

Light Independent Stage of Photosynthesis Location – Stroma Light is NOT required Steps CO2 enters the cycle ATP and NADPH use energy and high energy electrons to make a sugar Calvin cycle goes around 3 times before a sugar is formed.

Overview of Photosynthesis

Factors affecting Photosynthesis Temperature – photosynthesis likes warm temps but too hot and too cold can slow down the rate of photosynthesis Light Intensity – an increase in light intensity will increase the rate of photosynthesis until a certain point, then it will not have an effect. Water – water is a reactant, without water, photosynthesis will not occur and the plants will die.