PHOTOSYNTHESIS Chapter 8 ENERGY LIFE ENERGY The ability

PHOTOSYNTHESIS Chapter 8

ENERGY &LIFE

ENERGY The ability to do work. Can be stored in chemical bonds. Cells need energy to do things like active transport, dividing, moving, and producing and storing proteins. http: //www. youtube. com/watch? v=qyb. UFn Y 7 Y 8 w https: //www. youtube. com/watch? v=YWk 9 N 92 -wvg

AUTOTROPHS VS. HETEROTROPHS Autotrophs Heterotrophs Organisms that make their own food. AKA: Ex: producers plants that obtain energy from the food that they eat. AKA: consumers or decomposers Ex: sheep, wolves, mushrooms

ATP (ADENOSINE TRIPHOSPHATE) The main energy storage compound for living things.

ADP (ADENOSINE DIPHOSPHATE) When a cell has extra energy, it stores it by adding a phosphate group to ADP, making ATP. To release the energy, the bond is broken, converting ATP back to ADP.

PHOTOSYNTHESIS: AN OVERVIEW

LIGHT & PIGMENT White light is actually a mixture of different wavelengths of light. (from sun) Pigments: light absorbing molecules that gather the sun’s energy. � The plant’s principle pigment is chlorophyll. (remember any others? ) Energy absorbed by chlorophyll is transferred directly to electrons in the chlorophyll molecule. These electrons help photosynthesis work.

SO WHY ARE LEAVES GREEN? • Look at the wavelengths of light that chlorophyll absorbs & uses in photosynthesis • The colors that are left are reflected back and that is what you see. (green)

PHOTOSYNTHESIS: AN OVERVIEW ● THE PROCESS THAT CAPTURES LIGHT ENERGY AND USES IT TO MAKE CARBOHYDRATES (GLUCOSE). sunlight 6 H 2 O + 6 CO 2 -----> C 6 H 12 O 6+ 6 O 2 Water: Comes in through the roots Carbon Dioxide: Comes in from the air Glucose: Stored as chemical energy Oxygen: leaves back to the air

WHERE DOES IT TAKE PLACE? In the chloroplasts. (where are these? )

THE FACTORS AFFECTING PHOTOSYNTHESIS

FACTORS AFFECTING PHOTOSYNTHESIS AND ENVIRONMENTAL SCIENCE Temperature (Impacts? ) � Best between 0 & 35˚C Light intensity (Impacts? ) �A higher intensity increases the rate of photosynthesis until a maximum rate is reached. Water (Impacts? ) �A shortage can stop photosynthesis. CO 2 (Impacts? ) �A higher intensity increases the rate of photosynthesis until a maximum rate is reached. http: //www. youtube. com/watch? v=Lg. YPee. ABo. Us

CELLULAR RESPIRATION & FERMENTATION Chapter 9

CELLULAR RESPIRATION Releases energy (ATP) by breaking down food in the presence of oxygen. C 6 H 12 O 6 + 6 O 2 -----> 6 H 2 O + 6 CO 2 Glucose: Plants - have it stored from photosynthesis; Animals- get it from food Oxygen: taken in from the air Water: released as waste Carbon Dioxide: released into the air

CALORIE The amount of energy needed to raise 1 g of H 2 O 1˚C. �When burned, 1 g of glucose releases 3811 calories of heat energy. Food labels show Calories (= 1000 calories). (kcal)

THE PROCESS OF CELLULAR RESPIRATION Three Parts: � Glycolysis � Kreb’s Cycle � Electron Transport Chain

GLYCOLYSIS Where? (The cytoplasm)

KREB’S CYCLE Where? The mitochondria

ELECTRON TRANSPORT CHAIN Where? The mitochondria

FERMENTATION

AEROBIC VS. ANAEROBIC When O 2 is present & all of cellular respiration occurs, 36 ATPs are made from 1 C 6 H 12 O 6. � Aerobic: reactions that require oxygen When there is no O 2, only glycolysis occurs and less energy comes from 1 C 6 H 12 O 6. � Anaerobic: reactions that do not need oxygen (glycolysis). Uses back up stored energy but will run out. Then comes Fermentation.

FERMENTATION Allows glycolysis to continue by converting energy to a usable form. (NADH into NAD+) Anaerobic Two types: � Alcoholic fermentation (happens in fruit, ethanol, bread, some fish) � Pyruvic acid + NADH -> alcohol + CO 2 + NAD+ Lactic Acid fermentation (exercise) Pyruvic acid + NADH -> lactic acid + NAD+