Chapter 8 and 9 P HOTOSYNTHESIS AND C ELLULAR R ESPIRATION

T OPICS  Big questions : - How do you make energy? -How do plants get their food?  We will discuss:  ATP  Cellular Respiration  Photosynthesis

ATP  Energy currency of the cell  Adenosine Triphosphate = Adenine and three phosphates

ATP  ATP holds energy between the phosphate bonds  How do you get the energy out of ATP?

ATP  When we take the phosphate off the molecules becomes ADP – Adenosine diphosphate ‘Di’ means 2!  How do we make ATP?

C ELLULAR R ESPIRATION -O CCURS IN ALL LIVING THINGS, ALL THE TIME

C ELLULAR R ESPIRATION  Cellular respiration is the process that cells use to make ATP, or energy  So what do we need to make energy? Food – glucose (C 6 H 12 O 6 ) Oxygen – We ALWAYS need oxygen

C ELLULAR R ESPIRATION

 Remember:  We need oxygen and food to make energy!  Inhale: Oxygen (O 2 )  Exhale: Carbon Dioxide (CO 2 )

C ELLULAR R ESPIRATION  There are two types of respiration:  Aerobic – Requires oxygen  Anaerobic – does not require oxygen  Do you think you make more energy with or without oxygen?

C ELLULAR R ESPIRATION  There are three steps to cellular (aerobic) respiration-  Glycolysis (2 ATP)  Krebs cycle (2 ATP)  Electron transport chain (32 ATP)

E NERGY MADE IN C ELLULAR RESPIRATION  Cellular Respiration makes ATP  Occurs in the mitochondria of the cell *Remember this is WITH OXYGEN

C ELLULAR R ESPIRATION  What happens when we don’t have oxygen?  Fermentation!  2 types  Makes 2 ATP

F ERMENTATION 1. Lactic Acid – happens in animal cell, produces lactic acid (sore muscles) 2. Alcoholic Fermentation – happens in yeast cells, produces ethanol and carbon dioxide (Make beer and wine)

V IDEO C LIP  Q Q

P HOTOSYNTHESIS

 Photosynthesis is the process that plants use to turn light energy into food  What do plants need?  Photosynthesis equation Light + CO 2 + H 2 O O2 + Glucose

P HOTOSYNTHESIS  Where is the plant do you think this occurs?  Leaves  Where in the leaf does this occur?  Palisade mesophyll  Where in the cell does this occur?  Chloroplast

C HLOROPHYLL  Chlorophyll is the substance in the leaf that absorbs the light?  Why is chlorophyll green?  Absorbs all colors except green  Reflects the color green

U NIT V OCABULARY  Autotroph: an organism that can make their own food  Ex/Tree, flower, plant  Heterotroph: Organism that must get food from elsewhere. Can not make their own food  Ex/ animals, people

P HOTOSYNTHESIS  Occurs during the day when the sun is out  Autotrophs use photosynthesis  Then Cellular respiration is used to break down the energy made  1% of solar energy that reaches the earth is used in photosynthesis

P HOTOSYNTHESIS S TAGES  Light reaction (light dependent)  Requires light – light helps makes ATP  In the thylakoid membrane (inside chloroplast)

P HOTOSYNTHESIS S TAGES  Dark reaction (light independent/Calvin cycle)  Does not require light  In the stoma (inside chloroplast)  ATP (from lights rxns) is used to convert CO2 to sugar

P HOTOSYNTHESIS AND R ESPIRATION  How are photosynthesis and cellular respiration connected? One’s reactants are the other’s products! Light + CO 2 + H 2 O O2 + Glucose Glucose +O2 CO 2 + H 2 O + ATP

V IDEO CLIP  Comparison:  Song: