2. CELLULAR RESPIRATION

3. OVERVIEW C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy (36 ATP) Opposite of photosynthesis Energy being released from food in the presence of oxygen 3 stages of cellular respiration 1.Glycolysis  No oxygen needed 2.Krebs cycle  Oxygen needed 3.Electron transport chain (ETC)  Oxygen needed

4. PRESENCE OF OXYGEN If reaction takes place using oxygen, it is said to be aerobic (Krebs and ETC)aerobic If reaction takes place without oxygen, it is said to be anaerobic (Glycolysis)anaerobic

5. ENERGY IN FOOD

6. GLYCOLYSIS (SPLITTING OF SUGAR) 1 st step in cellular respiration Glucose (6C) splits into 2 pyruvic acids (3C) Occurs in the cytoplasm Does NOT require oxygen Steps of glycolysis 1.2 ATP  2 ADP energy released is used to split glucose 2.Transfer of electrons (H + ions) to 2 NAD + to make 2 NADH 3.4 ADP  4 ATP

8. SUMMARY 2 ATP  2 ADP, 2 NAD+  2 NADH, 4 ADP  4 ATP, 1 glucose  2 pyruvic acids Overall products 2 pyruvic acids, 2 NADH, 2 ATP Advantages of glycolysis Occurs very quickly Does not require oxygen

9. KREBS CYCLE 2 nd step of cellular respiration Takes place in the matrix of the mitochondriamatrix Requires oxygen

10. KREBS CYCLE CONT. Steps 1.2 pyruvic acids break down into 2 acetic acids. 2 CO 2 are released 2 NAD +  2 NADH 2.Acetic acid joins with Coenzyme A  acetyl-CoA 3.Acetyl group is transferred to a 4C molecule to make Citric acid (6C)  starts Krebs cycle (AKA citric acid cycle) 4.6C molecule gradually breaks down into a 4C molecule a)2 CO 2 is released b)Electrons are transferred to 4 NADH c)Electrons are transferred to 1 FADH 2 d)1 ATP is formed To ETC

12. SUMMARY OF KREBS 1.8 NADH 2.2 ATP 3.2 FADH 2 4.6 CO 2 released Glycolysis & Krebs a)10 NADH b)2 FADH 2 c)4 ATP

13. ELECTRON TRANSPORT CHAIN 3 rd and final step of cellular respiration Takes place in the inner membrane of mitochondria in eukaryotes and in the cell membrane of prokaryotes. Requires oxygen

14. ETC CONT. High energy electrons from glycolysis & Krebs are transported to the ETC by NADH &FADH 2 Electrons pass from carriers through the ETC to oxygen to form water As e - pass through ETC they lose energy Energy lost from e-, is used to pump H+ across the membrane With a high conc. of H+ outside of the membrane and a low conc. Inside the membrane H+ pass through ATP synthase ATP synthase rotates and adds a phosphate group to ADP to make ATP.

15. ELECTRON TRANSPORT CHAIN

16. ATP FORMATION For every 2 electrons that pass through the ETC, enough energy is released to produce 3 molecules of ATP. 32 ATP are produced by ETC Cellular respiration summary of ATP Glycolysis + Krebs + ETC 2 + 2 + 32 = 36 ATP / glucose C 6 H 12 O 6 + 6 O 2  36 ATP + 6 CO 2 + 6 H 2 O

17. FERMENTATION Produces ATP from food without the use of oxygen Glycolysis produces ATP and NADH, but it can’t continue if there is no NAD + Fermentation returns NADH to NAD + Glycolysis and fermentation are called anaerobic respiration 2 forms of fermentation 1.Alcoholic fermentation 2.Lactic acid fermentation

18. ALCOHOLIC FERMENTATION Yeast and other microorganisms Produce ethyl alcohol and CO2 Pyruvic acid + NADH  ethyl alcohol + CO 2 + NAD + Used to make alcoholic beverages and to make bread rise

19. LACTIC ACID FERMENTATION Most organisms Pyruvic acid + NADH  Lactic acid + NAD + Used to produce food  Gives sour taste Cheese, yogurt, buttermilk, sour cream, pickles, sauerkraut Humans are lactic acid fermenters Muscle cells are best adapted for lactic acid fermentation

20. TYPES OF FERMENTATION

21. ENERGY SUPPLY Three sources of ATP 1.ATP already in the muscles 2.ATP make through lactic acid fermentation 3.ATP made from cellular respiration

22. SHORT TERM ENERGY Muscles only contain enough ATP for a few seconds of intense activity After that ATP is produced by lactic acid fermentation Makes enough ATP for about 90 seconds of activity Lactic acid builds up in muscles and takes excess oxygen to get rid of acid In quick bursts of energy, the body uses ATP already in the body along with ATP made through lactic acid fermentation.

23. LONG TERM ENERGY For activity lasting longer than 90 seconds, cellular respiration is the only way to continue producing ATP Glycogen in the muscles supplies energy for 15 – 20 minutes. After that other stored molecules (such as fats) are broken down.