Photosynthesis What You Need to Know

What Is It? Photosynthesis: A series of reactions that use light energy from the sun to synthesize (to make) large, energy rich molecules from smaller ones. Energy + 6(CO2) + 6(H20)  C6H12O6 + 6(O2)

Who Does Photosynthesis? Plants Algae Some Bacteria

Where Does This Happen? All phases of photosynthesis occur in the chloroplast A plant cell can have multiple chloroplast Not all plant cells have chloroplast (i.e. roots cells) http://sps.k12.ar.us/massengale/images/chloroplast.jpg

How Does It Really Work? Photosynthesis occurs in two phases 1. Chlorophyll absorbs light energy and converts it to chemical energy (ATP) ATP is short term energy storage 2. ATP is used to reorganize CO2 and H2O into carbohydrates. Carbohydrates are long term energy storage

What Happens After Photosynthesis? Plant cells use the carbohydrates from photosynthesis for energy to Continue cell functions Grow new cells Reproduce All other functions requiring energy

Amino Acid (building block of proteins) H C H O N H O Water Glucose Amino Acid (building block of proteins) H C O Glycerol + 3 Fatty Acids = Lipid (fat)

Cellular Respiration What You Need to Know

What Is It? Cellular Respiration: The process by which enzymes convert the energy in macromolecules (like carbohydrates) into usable ATP. Example: C6H12O6 + 6(O2) Energy + 6(CO2) + 6(H20)

All Living Organisms Use Cellular Respiration?

Where Does This Happen? Most of cellular respiration occurs in the mitochondrion Some cells have multiple mitochondrion http://microscopy.fsu.edu/cells/mitochondria/images/mitochondriafigure1.jpg

How Does It Really Work? Cellular Respiration occurs in three phases 1. Glycolysis 2. Krebs Cycle 3. Electron Transport System/ chain (ETC)

Glycolysis Glycolysis: Splits glucose into two smaller molecules Releases a little ATP Remaining molecules still have lots of “stored” energy

Krebs Cycle Enzymes break down the two molecules from glycolosis into CO2. This produces several more ATP Attaches hydrogen atoms to “carrier” molecules called NADH

Electron Transport Each hydrogen atom is separated into one electron and proton Electrons travel along transport chain Each electron transport releases 3 ATP That’s a lot of ATP http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/metabolism/photosyn/images/u4fg44.jpg

Is This the Only Way? NO There are other pathways to release energy in human cells for short periods of time There are also other pathways for certain organisms that are completely different