1. Focus Question: What happens during Cell Respiration? 3.7 Cell Respiration 8.1 Cell Respiration (a little) This lesson will be posted under 3.7 Reading: 6.1-6.3 Web Activities: 9A-9C

2. Cell Respiration Defined  Cell Respiration- the controlled release of energy in the form of ATP from organic compounds in cells.

3. Mitochondria

4. Cellular Respiration:  Cellular respiration breaks up glucose in a series of steps and taps the energy carried by electrons  Respiration works by shuttling electrons through a series of energy-releasing reactions  At each step electrons start out in a molecule with more energy and end up in a molecule with less energy  The reactions release small amounts of energy and the cell stores some of the energy in ATP

5. Redox Reactions  Are the energy-releasing reactions  Redox = oxidation/reduction reaction  Oxidation- loss of electrons-oxidized when it loses one or more e -  Generally involves gaining O or losing H  Reduction- gain of electrons- reduced when it gains one or more e -  Generally involves losing O or gaining H  Hint: to follow the electrons, look at where Hydrogen goes.

6. Redox  In photosynthesis this was our reduction  NADP + + H + NADPH

7. Common Redox Reactions in Cellular Respiration:  C 4 H 6 O 5 + NAD + C 4 H 4 O 5 + NADH + H +  What is being oxidized? C4H6O5C4H6O5C4H6O5C4H6O5  What is being reduced?  NAD +

8. Types of Cellular Respiration:  Anaerobic  NO OXYGEN PRESENT  Yields a small amount of ATP  Makes lactate (lactic acid) in humans  Makes alcohol in yeasts  Occurs In the cytoplasm  Aerobic  OXYGEN PRESENT  Yields LOTS of ATP  Makes water and CO 2  Occurs in the Mitochondria

9. Step #1 for All kinds of Cell Respiration:  Glycolysis- the break down of 1 glucose (6C) into 2 pyruvate (3C), with a small yield of ATP.  Takes place in the cytoplasm  Does NOT require oxygen

10. A Deeper Look @ Glycolysis  1. Phosphorylation  2 ATP molecules are used- P added to glucose (6C)  2. Lysis  Molecule is split producing 2 triose phosphates (3C each)

11. A Deeper Look Cont…  3a. Oxidation of TP  Occurs by a reduction of  2H + + NAD + NADH  (GAINED ELECTRONS)  2 are made  3b. Phosphorylation:  Inorganic Phosphate from the cytoplasm attaches to Trios BiPhosphate  4. ATP Formation:  Each TBiP gives up a phosphate which is taken up by ADP (4 ATP’s made)  New molecule formed is PYRUVATE!! (2 Pyruvates made) TP

12. Glycolysis  Glycolysis  --occurs in the cytoplasm  --glucose (6 carbons) is broken down into two pyruvate molecules (3 carbons each) --ATP consuming phase - 2 ATP are consumed --ATP producing phase - 4 ATP are produced --NET GAIN OF 2 ATP --2 NADH are produced which can be used to make more ATP in oxidative phosphorylation --NET GAIN OF 2 NADH  Animation of Glycolysis Animation of GlycolysisAnimation of Glycolysis  *If you remember one thing about glycolysis, remember that it yields 2 pyruvate, 2 ATP, and 2 NADH

13. From Glycolysis take one of two pathways: anaerobic respiration anaerobic respiration Glycolysis -or- aerobic respiration aerobic respiration Today, we follow glycolysis into anaerobic respiration.

14. Anaerobic Respiration:  Fermentation:  Alcoholic fermentation  Lactic acid fermentation

15. Alcoholic Fermentation:  Yeasts- can survive in an environment w/out Oxygen by only doing glycolysis….but  They need a way to replenish the supply of NAD + because it is reduced  This is done by converting the pyruvic acid into CO2 and ethanol (alcohol)

16. Lactic Acid Fermentation:  Rather than alcohol being produced lactic acid is produced  No CO2 is released so lactic acid keeps all 3 carbons  This type of fermentation is used to make cheese and yogurt  Muscles also make ATP this way when oxygen is scarce