Photosynthesis Photosynthesis Photosynthesis building glucose chemical energy by

Photosynthesis

Photosynthesis • Photosynthesis = building glucose (chemical energy) by using the sun’s energy (electromagnetic energy) • Occurs in the chloroplast – means “green container” • Uses sunlight, water, & CO 2 • Makes glucose (chemical energy) & oxygen (waste product)

Thylakoids – contain chlorophyll. Site of the light reaction. Stroma – watery space surrounding the thylakoid. Site of the DARK reaction. Granum – stack of thylakoids

Photosynthesis Equation REACTANTS PRODUCTS 6 CO 2 + 6 H 20 + sunlight C 6 H 12 O 6 + 6 O 2 carbon dioxide + water + energy glucose + oxygen

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 – 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: • CO 2, ATP, NADPH – What gets made: • Glucose (C 6 H 12 O 6)

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

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

Rate of photo. Light Intensity CO 2 Levels Temperature

2 Concerns for plants • Getting water & keeping water. • 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! • 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. • Low water, guard cells may keep stomata closed. • Stomata are open during the day when photosynthesis is happening. • 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