ATP

1. ATP Why do we use it for Energy?

2. ATP: Adenosine Triphosphate • Consists of Adensosine + 3 Phosphates • Highly unstable molecule • 3 phosphates each highly negative repel each other (like the wrong end of a magnet) • Hence a phosphate group is removed through hydrolysis energy is released (-7.3 kcal/mole) and breaks down into the more stable molecule ADP.

3. ATP: Pictures Where does the Negativity come from? Oxygen I thinkhe’s a bitunstable…don’t you? Oxygen

4. How does ATP store energy? Each negative PO4 more difficult to add a lot of stored energy in each bond most energy stored in 3rd Pi = releases energy ∆G = -7.3 kcal/mole 3rd Pi is hardest group to keep bonded to molecule Bonding of negative Pi groups is unstable spring-loaded Pi groups “pop” off easily & release energy O– O– O– O– O– O– O– O– P P P P P P P P –O –O –O O– O– O– –O –O –O O– O– O– –O –O O– O– O O O O O O O O ADP AMP ATP Instability of its P bonds makes ATP an excellent energy donor

5. ATP / ADP cycle + Pi ATP • Can’t store ATP • good energy donor, not good energy storage • too reactive • transfers Pi too easily • only short term energy storage • carbohydrates & fats are long term energy storage cellularrespiration 7.3 kcal/mole ADP A working muscle recycles over 10 million ATPs per second Whoa!Pass methe glucose (and O2)!

6. Completely off Topic • A Reminder: How can you remember what happens in Oxidation or Reduction? • OIL RIG • Oxidation is Loss of Electrons (or H) • Reduction is Gain of Electrons (or H) • PS. Making ATP is phosphorylation not Oxidation or reduction.

7. CELLULAR RESPIRATIONC6H12O6 + O2→ CO2 + H2O + energy

8. What questions should you be able to answer at the end of the unit? • Why do you breath in oxygen? • What do you breath out and why? • How do mitochondria work? • What is the difference between aerobic and anaerobic respiration? • What are the steps of Glycolysis? • What are the steps of Aerobic and Anaerobic Respiration?

9. CELLULAR RESPIRATION • The complex process in which cells make ATP by breaking down organic compounds is known as cellular respiration.

10. 2 2 NADH + 2H+ pyruvic acid 36

11. ANAEROBIC RESPIRATION • When O2 is absent, respiration is anaerobic and includes glycolysis and fermentation.

12. GLYCOLYSIS • Glycolysis is a pathway in which one molecule of glucose is oxidized to produce two molecules of pyruvic acid. • Takes place in the cytosol of the cell. • Fig 9.8 in your book!

13. Glycolysis Continued • The endproducts are 2 NADH, and 4 ATP • First 3 steps of Glycolysis are endothermic, require energy in the form of 2 ATP. Subsequent steps are exothermic. • What is the Net ATP produced by Glycolysis? Overview of Glycolysis

14. 2 ATP • + • 4 ATP • 2 ATP per molecule of glucose.

15. What happens if you have too much ATP? Allosteric Enzyme • Allosteric Inhibition • PFK (Phosphofructokinase): Enzyme used in step 3 of glycolysis to create the 6 carbon sugar that breaks apart into P-C-C-C C-C-C-P • Too much energy? ATP binds to the PFK halting the steps of gycolysis. • PS this is not in your book from what I’ve seen, but it’s in all the cheat manuals. So you may need to know it!

16. FERMENTATION (9.5, pg 177) • When there is no oxygen available, the products of glycolysis enter fermentation where no further ATP is yielded however NAD is regenerated and is available for glycolysis again.

17. Figure 9.18 Pg. 178 Figure 9.18 Fermentation, Pg. 178

18. Figure 9.18 Fermentation, Pg. 178

19. ENERGY YIELD

20. Who uses Anaerobic Respiration? • You do with Aerobic Respiration • Some bacteria survive on it (Botulinum & Tetnus) and can not survive in the presence of O2. They are Obligate anaerobes. • Facultative anaerobes can tolerate oxygen: Staph, E.Coli • Anaerobic R. began Millions of years ago when earths atm. Had no O2.

21. AEROBIC RESPIRATION • If oxygen is available, pyruvic acid enters the pathways of aerobic respiration: the Krebs cycle and the electron transport chain. Figure 9.11 Pg. 170-172

22. OVERVIEW OF AEROBICRESPIRATION • In the Krebs cycle, the oxidation of glucose that began with glycolysis is completed and NAD is reduced to NADH. • In the electron transport chain, NADH is used to make ATP. • Prokaryotes: Cytosol • Eukaryotes: Mitochondrial Matrix The Mitochondria At Work

23. When pyruvic acid reacts with a molecule called coenzyme A to form acetyl coenzyme A. Making Vinegar

24. The Krebs Cycle/Citric Acid Cycle • Cyclic process that produces the following products: CO2, ATP, NADH + H+, and FADH2. • CO2 is released. • NADH + H+, and FADH2 go to the electron transport chain. Krebs Cycle At the Bottom

26. ELECTRON TRANSPORTCHAIN Figure 9.13 Pg. 173 • In prokaryotes, the electron transport chain lines the cell membrane. • ATP is produced by the electron transport chain when NADH and FADH2 release hydrogen atoms, regenerating NAD and FAD. E.T.C. revisited Electron Transport Chain

27. Virtual Cell ETC

28. ATP synthase Enzyme channel in mitochondrial membrane permeable to H+ H+ flow down concentration gradient flow like water over water wheel flowing H+ cause change in shape of ATP synthase enzyme powers bonding of Pi to ADP:ADP + Pi ATP Virtual Cell H+ H+ H+ H+ H+ H+ H+ H+ rotor rod + P catalytic head H+ ADP ATP But… How is the proton (H+) gradient formed?

29. Oxidative Phosphorylation Occurs during chemiosmosis 90% of ATP produced in the ETC. Substrate-level phosphorylation When the enzyme kinase transfers a phosphate from a substrate directly to ADP. In Glycolysis and Krebs cycle. Fig 9.7 Two types of phosphorylation Turn your flashcard paper over to Table 5.1 to review ATP allotments.

30. Why Do We Study Glycolysis? • New Research • And… HHMI Cancer Research Importance Of Studying Glycolysis

31. New Research to find the Cure for Cancer. • P53: Using Viruses • Stopping Glycolysis • Cancer cells do not use Citric Acid Cycle or Electron Transport chain-due to Hypoxic (No/Low Oxygen) Conditions it creates • Hypoxia good for Cancer,bad for body cells • Cancer Cells glycolysis becomes ultra efficient P53