Question… Where do you get all of your energy to survive? Photosynthesis – using light energy, carbon dioxide, and water to make food for the plant. (glucose) How does the plant do this? What parts of the plants help this process? How does the plant absorb light?

Energy In A Cell Chapter 9

The Need for Energy (Ch. 9, Sec. 1) All organisms need ENERGY Plants (autotrophs) obtain energy from the sun Other organisms (heterotrophs) eat plants to get the plant’s stored energy

ATP Adenosine Triphosphate = 1 adenosine molecule, 1 ribose molecule, + 3 phosphate groups Energy is stored in the bonds between the phosphates When the bond breaks, energy is released Phosphate can be reattached to ‘recharge’ the ATP molecule

Photosynthesis Ch. 9, Sec. 2

Photosynthesis = plants use sunlight energy, carbon dioxide and water to make simple sugars (glucose) 6CO2 + 6H2O  C6H12O6 + 6O2 Occurs in 2 phases Light-dependent Reactions Light-independent Reactions

Chloroplasts & Pigments Chloroplasts: where photosynthesis takes place (contains pigment: chlorophyll)

Pigments = compounds that absorb light Most common: chlorophyll, carotenoids Visible Light made up of a range of colors ROY G BIV Colors that don’t get absorbed, are reflected, and are what you see

Thylakoid Membranes contain pigments Chlorophyll pigment that gives plants their green color Carotenoids pigments in plants that become visible when plants stop producing chlorophyll

Light-Dependent Reactions 1st phase of Photosynthesis, requires light energy Energy gets captured by electrons The energized electron splits a water molecule causing Oxygen to be released and ATP to be generated

Light-Independent Reactions Calvin Cycle = 2nd part of photosynthesis, does not require light Uses CO2 and H to form sugars Takes place in the chloroplast Generation of the sugars requires ATP produced during the Light-Dependent Reactions

End result… 1 molecule of glucose (C6H12O6) and 6 molecules of oxygen (O2) waste.

Practice What are the inputs for photosynthesis? What are the outputs for photosynthesis? Is a product considered an input or output? Explain.