Atp Teach Intro
- 1. ATP Making energy! The point is to make ATP !
- 2. The energy needs of life Organisms are endergonic systems What do we need energy for? synthesis building biomolecules reproduction movement active transport temperature regulation
- 3. Where do we get the energy from? Work of life is done by energy coupling use exergonic (catabolic) reactions to fuel endergonic (anabolic) reactions + + energy + energy + digestion synthesis
- 4. Living economy Fueling the body’s economy eat high energy organic molecules food = carbohydrates, lipids, proteins, nucleic acids break them down digest = catabolism capture released energy in a form the cell can use Need an energy currency a way to pass energy around need a short term energy storage molecule ATP Whoa ! Hot stuff !
- 5. ATP Adenosine TriPhosphate modified nucleotide nucleotide = adenine + ribose + P i AMP AMP + P i ADP ADP + P i ATP adding phosphates is endergonic How efficient! Build once, use many ways high energy bonds
- 6. How does ATP store energy? Each negative PO 4 more difficult to add a lot of stored energy in each bond most energy stored in 3rd P i 3rd P i is hardest group to keep bonded to molecule Bonding of negative P i groups is unstable spring-loaded P i groups “pop” off easily & release energy Instability of its P bonds makes ATP an excellent energy donor I think he’s a bit unstable… don’t you? AMP ADP ATP P O – O – O – O P O – O – O – O P O – O – O – O P O – O – O – O P O – O – O – O P O – O – O – O P O – O – O – O P O – O – O – O
- 7. How does ATP transfer energy? ATP ADP releases energy ∆ G = -7.3 kcal/mole Fuel other reactions Phosphorylation released P i can transfer to other molecules destabilizing the other molecules enzyme that phosphorylates = “ kinase ” 7.3 energy + ADP ATP P O – O – O – O P O – O – O – O P O – O – O – O P O – O – O – O
- 8. An example of Phosphorylation… Building polymers from monomers need to destabilize the monomers phosphorylate! It’s never that simple ! +4.2 kcal/mol “ kinase” enzyme -7.3 kcal/mol -3.1 kcal/mol synthesis C H OH H H O C C H O H C + H 2 O + C H OH C H P + ATP + ADP H H O C + C H O H C C H P + P i enzyme H OH C H H O C
- 9. Another example of Phosphorylation… The first steps of cellular respiration beginning the breakdown of glucose to make ATP glucose C-C-C-C-C-C fructose-1,6bP P- C-C-C-C-C-C -P DHAP P- C-C-C G3P C-C-C -P Those phosphates sure make it uncomfortable around here ! activation energy hexo kinase phosphofructo kinase C H P C P C ATP 2 ADP 2
- 10. ATP / ADP cycle Can’t store ATP good energy donor, not good energy storage too reactive transfers P i too easily only short term energy storage carbohydrates & fats are long term energy storage A working muscle recycles over 10 million ATPs per second Whoa ! Pass me the glucose (and O 2 ) ! ATP ADP 7.3 kcal/mole cellular respiration P i +
- 11. Cells spend a lot of time making ATP ! What’s the point? The point is to make ATP !
- 12. 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 P i to ADP: ADP + P i ATP ATP But… How is the proton (H + ) gradient formed? ADP H + catalytic head rod rotor H + H + H + H + H + H + H + H + P +
- 13. That’s the rest of my story ! Any Questions?
Editor's Notes
- #3: Which is to say… if you don’t eat, you die… because you run out of energy. The 2nd Law of Thermodynamics takes over!
- #6: Marvel at the efficiency of biological systems! Build once = re-use over and over again. Start with a nucleotide and add phosphates to it to make this high energy molecule that drives the work of life. Let’s look at this molecule closer. Think about putting that Pi on the adenosine-ribose ==> EXERGONIC or ENDERGONIC ?
- #7: Not a happy molecule Add 1 st Pi Kerplunk! Big negatively charged functional group Add 2 nd Pi EASY or DIFFICULT to add? DIFFICULT takes energy to add = same charges repel Is it STABLE or UNSTABLE? UNSTABLE = 2 negatively charged functional groups not strongly bonded to each other So if it releases Pi releases ENERGY Add 3 rd Pi MORE or LESS UNSTABLE? MORE = like an unstable currency • Hot stuff! • Doesn’t stick around • Can’t store it up • Dangerous to store = wants to give its Pi to anything
- #8: How does ATP transfer energy? By phosphorylating Think of the 3rd Pi as the bad boyfriend ATP tries to dump off on someone else = phosphorylating How does phosphorylating provide energy? Pi is very electronegative. Got lots of OXYGEN!! OXYGEN is very electronegative. Steals e’s from other atoms in the molecule it is bonded to. As e’s fall to electronegative atom, they release energy. Makes the other molecule “unhappy” = unstable. Starts looking for a better partner to bond to. Pi is again the bad boyfriend you want to dump. You’ve got to find someone else to give him away to. You give him away and then bond with someone new that makes you happier (monomers get together). Eventually the bad boyfriend gets dumped and goes off alone into the cytoplasm as a free agent = free Pi.
- #9: Monomers polymers Not that simple! H 2 O doesn’t just come off on its own You have to pull it off by phosphorylating monomers. Polymerization reactions (dehydration synthesis) involve a phosphorylation step! Where does the P i come from? ATP
- #10: These are the very first steps in respiration — making ATP from glucose. Fructose-1,6-bisphosphate (F1,6bP) Dihydroxyacetone phosphate (DHAP) Glyceraldehyde-3-phosphate (G3P) 1st ATP used is like a match to light a fire… initiation energy / activation energy. The Pi makes destabilizes the glucose & gets it ready to split.