Energy Transfer In Plants Changing the Sun’s Energy Into Useable, Stored Energy

All Life Needs Energy!!  Some life uses a process called chemosynthesis to make life possible.  Bacteria can get energy from thermal vents on the ocean floor!!!  Hydrogen sulfide chemosynthesis - CO 2 +O 2 +4{H 2 S}→CH 2 O+4{S}+3{H 2 O}  But even this depends on photosynthesis!! ( O 2 from plants )

Chloroplast Plant Cell Sunlight

Parts of the Plant Cell

Life Needs Useable Energy  Remember!! ATP is the useable form of energy in a cell!  In order for a plant to make ATP they must perform 2 processes, Photosynthesis & Cellular Respiration

BOTH Plants Do BOTH!!  Photosynthesis with Chloroplasts  And Cellular Respiration with Mitochondria

Where Does It Start?  Photosynthesis begins with Sunlight, when it hits the leaves of plants (and some protists or bacteria)

Photosynthesis has 3 stages I.Capture Light Energy II.Make Chemical Energy III.Store Energy In Carbohydrates

Photosynthesis: Stage 1  Light hits the chloroplast and is absorbed by a pigment called chlorophyll  A pigment is any light absorbing substance

Stage 1: Continued  In Stage 1, the energy from the light splits H 2 O into three parts:  Oxygen (O 2 )  Hydrogen Ions (H+)  Electrons (e-)

Photosynthesis: Stage 2  The H+ and e- are pushed through the electron transport chain to make NADPH  NADPH is like a rechargeable battery

Photosynthesis: Stage 3  This stage DOES NOT require LIGHT.  NADPH provides the energy to combine CO 2 molecules into carbohydrates such as glucose (C 6 H 12 O 6 )  This process is called the “Calvin Cycle”

Photosynthesis: The Reaction (6) CO 2 + (6) H 2 O C 6 H 12 O 6 + (6) O 2 Light Enzymes Reactants: Carbon Dioxide & Water Products: Glucose & Oxygen

What’s Next?  Some glucose is stored as starch.  The rest of it goes to the cytoplasm to begin to make ATP through Cellular Respiration!!