Bellwork Add these to your prefix/suffix sheet: photo—light an—without aero—air synthesis—to put together

9.1 Section Objectives – page 221

Energy in a Cell All organisms require energy for: Active transportActive transport Cell divisionCell division MovementMovement Production of proteinsProduction of proteins

Photosynthesis

Photosynthesis = building glucose (chemical energy) by using the sun’s energy (electromagnetic energy) Occurs in the chloroplast – means “green container” Uses sunlight, water, & CO2 Makes glucose (chemical energy=food for the plant) & oxygen (waste product) Carried out by green plants and some bacteria

Thylakoids – green disks in the chloroplast, contain chlorophyll. Site of the light reaction. Stroma – watery space surrounding the thylakoid. Site of the DARK reaction. Granum – stack of thylakoids

Thylakoids are green because they contain chlorophyll Chlorophyll—green pigment in plants that absorbs light energy Pigment—light absorbing compound

Photosynthesis Equation REACTANTS PRODUCTS 6 CO H sunlight  C 6 H 12 O O 2 carbon dioxide + water + light energy  glucose + oxygen (chemical energy)

Composed of 2 main reactions Light Dependent Reaction Light Independent Reaction Calvin Cycle Dark Reaction

Light-Dependent Reaction 1. Light-Dependent Reaction –The light phase –Occurs in the Thylakoid membrane within in the Chloroplast –First –First step of photosynthesis that traps sunlight and makes electrons and ATP to run the dark reaction –What gets used: H 2 O (water – split into H 2 and O) & sunlight –What gets made: ATP (energy), NADPH (energy carrier) Oxygen is released as waste

Light-Independent Reaction 2. Light-Independent Reaction –Also know an the Calvin Cycle or Dark Reaction –The “synthesis” phase –Occurs in the Stroma within in the Chloroplast –What gets used: CO2, ATP, NADPH –What gets made: Glucose (C 6 H 12 O 6 )

Thylakoids H2OH2O e H 2 \ O NADP + H2 C 6 H 12 O 6 CO 2 Stroma Chloroplast

Energy in a Cell ATP Energy is stored in the ATP molecule ATP: adenosine triphosphate 3Made up of adenosine + 3 phosphate groups

Energy in a Cell Adenosine Phosphate High-energy bond: Stores a lot of energy *This energy is released when the bond is broken* ATP Adenosine Phosphate Energy ADP

Energy in a Cell ADP: Adenosine diphosphate recycleATPCells recycle the ADP to make new ATP to store more energy for future use energyMany proteins have spots where ATP attaches to provide energy for the protein to do its job, then the ADP is released for recycling

Factors Affecting Photosynthesis Light Intensity –As light intensity increases, photosynthesis increases, to a certain point. Carbon Dioxide –As CO 2 increases, photosynthesis increases, to a certain point. Temperature –All chemical reactions are dependent on temperature

Light Intensity CO2 Levels Temperature Rate of photo.

2 Concerns for plants Getting water & keeping water.Getting water & keeping water. Plants developed roots in order to get water and they developed a cuticle to keep water in the leaves.Plants developed roots in order to get water and they developed a cuticle to keep water in the leaves. –Cuticle: waxy covering that surrounds the leaf and reduces transpiration (water loss by plants).

Stomata Solved the problem!Solved the problem! A stomata is a hole on the underside of a leaf that allows gas exchange. It is surrounded by guard cells. Reduces transpiration (water loss by leaves)A stomata is a hole on the underside of a leaf that allows gas exchange. It is surrounded by guard cells. Reduces transpiration (water loss by leaves)

Plants need water for 2 reasons: For photosynthesis and plumps guard cells – open up and allow for gas exchange.For photosynthesis and plumps guard cells – open up and allow for gas exchange. Low water, guard cells may keep stomata closed.Low water, guard cells may keep stomata closed. Stomata are open during the day when photosynthesis is happening.Stomata are open during the day when photosynthesis is happening. Stomata are closed at night when photosynthesis is not happening (& to reduce transpiration.)Stomata are closed at night when photosynthesis is not happening (& to reduce transpiration.)

FROOT LOOP KEY WINDOW SIDE PURPLE: OXYGEN GREEN: HYDROGEN RED: CARBON DOOR SIDE ORANGE: OXYGEN GREEN: HYDROGEN YELLOW: CARBON