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Cells capture and release energy. Chapter 2 – Section 2 Notes. PHOTOSYNTHESIS. “Photo-” = light “-syntesis” (synthesize) = to make something Definition – a step by step process that a plant uses to make GLUCOSE (sugar) from light
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Cells capture and release energy. Chapter 2 – Section 2 Notes
PHOTOSYNTHESIS • “Photo-” = light • “-syntesis” (synthesize) = to make something • Definition – a step by step process that a plant uses to make GLUCOSE (sugar) from light • Job is done in the CHLOROPLAST – specifically in the CHLOROPHYLL (light absorbing chemical inside the choloroplasts)
PHOTOSYNTHESIS Steps • Step one Plants collect CO2 (Carbon Dioxide) from the air and H2O from their roots to go inside the Chloroplasts • Step Two Chloroplasts use sun / light and a Chemical Reaction takes place to change the molecules • Step Three The elements rearrange and form GLUCOSE (sugar) and OXYGEN (waste for the plant)
PHOTOSYNTHESIS in Action • (see page 49 in the book) “makes” 6H20 + 6CO2 + lightC6H12O6 + 6O2 Chemical Equation for Photosynthesis • It takes, 6 Carbon Dioxide molecules and 6 water molecules being exposed to light to make just one molecule of Glucose and 6 Oxygen molecules. • http://www.classzone.com/books/ml_science_comp/page_build.cfm?id=none&mod=1# • BrainPop Video
All cells make and use energy Two Types of Energy Making and Releasing Cellular Respiration Fermentation Requires Oxygen NO Oxygen Required
CELLULAR RESPIRATION • Uses Glucose = “Cell Food” • Chemical Energy is stored in bonds between the elements • It requires Oxygen in order to work and releases LOTS of usable energy
Cellular Respiration Steps • Step one All cells collect “Carbohydrate” (Glucose) and Oxygen (leftovers from Photosynthesis in plants) and starts to break apart the “Carbohydrate”. • Step Two Mitochondria takes the “carbo-chunks” and has the oxygen break them into separate elements to be rearranged. • Step Three Chemical Energy gets released, and H2O and CO2 are made from the rearranged elements.
CELLULAR RESPIRATION in Action • (see page 51 in the book) “makes” C6H12O6 + 6O2 6H20 + 6CO2 + Energy Chemical Equation for Cellular Respiration • It takes, just one molecule of Glucose and 6 Oxygen molecules to make 6 Carbon Dioxide molecules and 6 water molecules with lots of Energy released to the cell to be used.
Now Put them together…. Photosynthesis and Cellular Respiration Cycle
Not quite done…. • Fermentation • Basically the same as Cellular Respiration…just different in that NO Oxygen is needed to get the Energy • It only releases a small amount of Energy • Does NOT happen in the Mitochondria, it happens in the Cytoplasm
Two Types of Fermentation… • Alcoholic Fermentation • “Sugar” is changed into an alcohol and CO2 without Oxygen being used • Example: Bread (made with flour, milk and sugar and yeast) – They have a Chemical Reaction and the small amount of alcohol evaporates and the CO2 makes the “bubbles” in the bread
Two Types of Fermentation… Type Two 2. Lactic Acid Fermentation • “Carbohydrates” are broken apart releasing their Energy – without Oxygen- and an acid is left • Examples: Yogurt (sits only a short time), Cheese (left to sit a long time) and Sourdough bread (made with milk) or the sugar “Lactose” as the “sugar / carb”. • Human Example: Exercising for a long time / distance…you will use up your Oxygen supply in the muscle and have to do Fermentation to make a little emergencyenergy. You feel “sore / pain / burn” sensation – this is the Lactic Acid build up. See BrainPop video…