PROCESSES NECESSARY FOR PLANT SURVIVAL 4/25/16

I. PHOTOSYNTHESIS ❖ Photo: light (sun) ❖ Synthesis: to make or synthesize ❖ Plants make simple sugar (food) for themselves ❖ Chloroplasts – found in the cells of leaves, contain chlorophyll which absorbs light energy ❖ Plants use carbon dioxide and water to make food ❖ CO2 is taken in through openings in the leaves called stomata ❖ Oxygen is released into the air through the stomata

Chloroplast: Organelle where photosynthesis occurs Chlorophyll: pigment that absorbs light energy

Photosynthesis Equation Reactants: e- (energy from sunlight) + water + CO2 Products: O2 + sugar (food)

What is the function of a guard cell? Stoma vs. guard cell?

II. Respiration ❖ Respiration (the act of breathing) ❖ To obtain energy from the food a plant produces, it must break down the sugar in the cells throughout the plant. This called respiration. ❖ Oxygen from the air combines with the sugar, which is then broken down into carbon dioxide and water. ❖ Energy is released during this process which the plant can use to perform life functions. ❖ The carbon dioxide and water that are formed are then given off through the stomata in the leaves.

Respiration Equation Reactants: O2 + sugar (food) Products: e- (energy from sunlight) + water + CO2

III. Transpiration ❖ Plants lose most of the water they absorb through their leaves. This is called transpiration. ❖ Plants can control transpiration by opening and closing their stomata. ❖ When the stomata are closed, water cannot escape. ❖ Guard cells on the underside of the leaf, open and close the stomata. ❖ Without a way to control this process, plants would wither up and die.