Cellular Respiration Mr. Graham

Harvesting Energy from Food!  Cellular respiration is a chemical reaction that uses oxygen to convert the chemical energy stored in organic molecules into ATP.

ATP  Adenosine triphosphate – it is the source of energy used for most cellular work.  When we take in food, ADP is converted to ATP in the process of cellular respiration.  When our cells use this energy, ATP is converted to ADP.

What can ATP be used for?  ATP can be used for: –Moving a Muscle Protein –Building Large Molecules –Active Transport

Synthesis and Active Transport

Aerobic Cellular Respiration  Aerobic = with oxygen  Occurs in the mitochondria  The use of oxygen releases more energy per glucose molecule than anaerobic = without oxygen  Uses oxygen but releases carbon dioxide and water SUMMARY EQUATION:

Cellular Respiration  Cellular Respiration is an aerobic process, meaning that it requires oxygen.

Both plant and animal cells carry out the final stages of cellular respiration in the mitochondria. Animal Cells Plant Cells Mitochondrion Outer membrane Intermembrane space Inner membrane Matrix

Cellular Respiration  There are three parts of cellular respiration. They are glycolysis, krebs cycle, and electron tranport system.

STAGES OF CELLULAR RESPIRATION  Respiration occurs in three main stages GLYCOLYSISKREBS CYCLE ELECTRON TRANSPORT CHAIN High-energy electrons carried by NADH Mitochondrion Cytoplasmic fluid

Cellular Respiration Glycolysis 2ATP Produced Cytoplasm Krebs Cycle 2ATP Produced Mitochondria Electron Transport System 34 ATP Mitochondria

Fermentation is an anaerobic alternative to aerobic respiration  Process operates by means of chemical reactions catalyzed by enzymes in cytoplasm of cell  Primary mode of energy production for some bacteria and fungi (yeast)  use glycolysis alone to produce small amounts of ATP  Important in production of foods such as cheese, buttermilk, yogurt, alcohol, (wine/beer) and bread  2 types: 1. alcohol & 2. lactic acid

Fermentation  Some organisms can ferment glucose to make energy. This is a form of anaerobic respiration.  The products of fermentation depend upon the type of organism. Some yeast ferment sugar and make alcohol as a by product.  What is a problem with fermentation?

Lactic Acid Fermentation  When oxygen levels decrease, your muscles make energy using lactic acid fermentation. The by product of this fermentation is 2ATP and lactic acid.

How do microbes help us?  Bacteria and fungi are used to tranform milk into yogurt and cheese. The sharpness or sour flavor of yogurt is due to lactic acid.

Photosynthesis

Energy and Life  Plants and some other types of organism are able to use light energy from the sun to produce food.  Autotrophs – organisms that are able to synthesize their own food.  Heterotrophs – obtain energy by consuming other organisms.

Photosynthesis  Plants use the energy of sunlight to convert water and carbon dioxide into oxygen and high energy carbohydrates.

Structure of a Leaf  Xylem – carries water from the roots to leaves.  Phloem – carries food (glucose) from leaves to the roots.  Stomata – tiny holes in bottom of the leaf that function in gas exchange.  Guard cells – control the opening and closing of guard cells.

Light and Pigments  In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll, a molecule found in chloroplasts.  Plants gather the suns energy with light absorbing molecules called pigments (chlorophyll).

Why are leafs green?  There are two types of chlorophyll, chlorophyll a and chlorophyll b. These pigments absorb red and blue light, and reflect green.

Other Pigments  Carotenoids, which produce yellow, orange, and brown colors in such things as corn, carrots, and daffodils.  Anthocyanins, which give color to such familiar things as cranberries, red apples, concord grapes, blueberries, cherries, strawberries, and plums.  Why do leaves change colors in the autumn?  During the growing season, chlorophyll is continually being produced and broken down and leaves appear green. As night length increases in the autumn, chlorophyll production slows down and then stops and eventually all the chlorophyll is destroyed. The carotenoids and anthocyanins that are present in the leaf are then unmasked and show their colors.

Paper Chromotography  Paper chromatography is a technique for separating and identifying mixtures that are or can be colored, especially pigments found in plants.

Rate of Photosynthesis  Amount of Water available  Temperature  Light Intensity  Amount of CO 2 present.

Comparing photosynthesis and Cellular Respiration