Cellular Respiration and Fermentation
How do plants and animals obtain the glucose they need? Plants: Animals:
Cellular Respiration the process that releases energy from food in the presence of oxygen Oxygen must be available for use
Cellular Respiration Equation 6O 2 + C H O 6 12 6 6 CO 2 + 6 H O + ATP 2
Match each part of the Cellular Respiration equation Carbon Dioxide 1st Reactant Glucose 2nd Reactant Water 1st Product ATP 2nd Product Oxygen 3rd Product
Remember! We are not producing energy in cellular respiration Instead, releasing it from organic molecules
Cellular Respiration Requirements Requires Oxygen and Glucose Release CO2 and H2O gradually Must be gradual of energy lost in form of light and heat There is a whole lot of energy!!! http://www.youtube.com/watch?v=johdzsqxw7i
Stages of Cellular Respiration Glycolysis Krebs Cycle Electron Transport Chain
Step 1: Glycolysis Glucose is broken down in the cytoplasm Formed from each glucose 2 molecules ATP 2 molecules NADH 2 pyruvate molecules
What is the yield of ATP for glycolysis? Answer:
Step 2: Krebs Cycle (citric acid cycle) Pyruvate broken down into carbon dioxide during Krebs cycle Ultimate goal to make NADH and FADH2 for step 3 (electron transport chain)
Step 2: Krebs Cycle (citric acid cycle) Prior to the Krebs cycle pyruvate reacts with coenzyme A (CoA) to form Acetyl CoA Releases CO2 and NADH Acetyl CoA then moves to mitochondrial matrix
Step 2: Krebs Cycle (citric acid cycle) Krebs cycle begins with acetyl CoA combining with a 4-carbon compound to make 6-carbon citric acid
Step 2: Krebs Cycle (citric acid cycle) Citric acid is broken down Releases 2 CO2 Generates: 1 ATP 3 NADH 1 FADH2
Step 2: Krebs Cycle (citric acid cycle) Remember: 2 molecules of pyruvate are formed Krebs turns twice! For each glucose molecule the net yield is: 6 CO2 2 ATP 8 NADH Needed for Next Step 2 FADH2
Step 3: Electron Transport Step where most ATP is produced Electrons move along the mitochondrial membrane from one protein to another
Step 3: Electron Transport As NADH and FADH2 release electrons, the H+ ions are released into mitochondrial matrix H+ ions are pumped across membrane Guess what it will be used for?
Step 3: Electron Transport ATP synthase is back again! Makes ATP when H+ diffuses down concentration gradient
Step 3: Electron Transport Electron transport chain produces: 24 ATP In eukaryotes one molecules of glucose yields 36 ATP
Fill in the following blanks for cellular respiration. 2. 1. 2. 3.
Amoeba Sister s Cellular Respiration https://www.youtube.com/watch?v=4eo7jtra7lg
What if there isn t enough oxygen!?
Anaerobic Respiration Occurs in low oxygen environments Some prokaryotes grow and reproduce without oxygen so they always do this!
Anaerobic Respiration - Fermentation Occurs in the cytoplasm and regenerates the cell s supply of NAD+ while producing a small amount of ATP 2 types: Lactic acid fermentation Alcohol fermentation
Lactic Acid Fermentation Enzymes convert pyruvate from glycolysis to lactic acid Skeletal muscles do this during strenuous exercise when oxygen supply is low
Alcohol Fermentation Occurs in yeast and some bacteria Pyruvate converted to ethyl alcohol and CO2
Amoeba Sister s Fermentation https://www.youtube.com/watch?v=ybdkbcu20_m