CELLULAR RESPIRATION Chapter 5 Section 3
Cellular Respiration Occurs in all organisms when Oxygen is available. Converts Food Energy ATP Two types of Cellular Respiration Aerobic = with O 2 Anaerobic = without O 2 C 6 H 12 O 6 + 6O 2 6 H 2 O + 6 CO 2 + ATP
Stages of Cellular Respiration 1. Glycolysis 2. Transition Step 3. Krebs Cycle (Citric Acid Cycle) 4. Electron Transport Chain
1. Glycolysis: biochemical pathway that occurs in Cytoplasm 2 ATP 2 ADP + P 4 ATP 4 ADP + 4 P 2 NAD + 2 NADH
2. Transition Step: biochemical pathway in Mitochondria Both Pyruvates are converted to Acetyl-CoA CO 2 and NADH are released
3. Krebs Cycle
3. Krebs Cycle: outer membrane of Mitochondria 2ATP 2ADP + 2P
4. Electron Transport Chain: Inner membrane of Mitochondria Proton Pumps ATP Synthetase
4. Electron Transport Chain: Inner membrane of Mitochondria Proton Pumps ATP Synthetase ATP ADP + P
4. Electron Transport Chain: Inner membrane of Mitochondria
NADH & FADH 2 drop off high energy e - /H high energy e - /H power proton pumps in mitochondria Creates concentration gradient ATP “used up” e - /H combines with O 2 H 2 O
Anaerobic Respiration: Fermentation Occurs when your cells are burning sugar faster than you can bring in the O 2. 2 types of fermentation Lactic Acid (animals) Alcoholic (fungus/yeasts)
Fermentation and the Electron Transport Chain:
Fermentation and the Krebs Cycle 2ATP 2ADP + 2P
Fermentation and the Transition Step Both Pyruvates are converted to Acetyl-CoA CO 2 and NADH are released
Why do we need Fermentation? If your cells can’t recycle the NAD + then… ETC shuts down Krebs Cycle Shuts down Stuck with pyruvate = death
Then what happens next? Fermentation recycles NADH NAD + Converts pyruvate to a new product (lactic acid) and allows NAD + to keep Glycolysis going = We Stay ALIVE!!!
Anaerobic Respiration: Lactic Acid Fermentation ATP ADP NAD + NADH
Anaerobic Respiration: Alcoholic Fermentation ATP ADP NAD + NADH
Cellular Respiration Overview Anaerobic (without O 2 ) Aerobic (with O 2 ) 2 ATP 34 ATP