AP Biology The Point is to Make ATP! ATP Making energy!

AP Biology Energy needs of life  Organisms are endergonic systems  What do we need energy for?   synthesis (biomolecules)  reproduction  active transport  movement  temperature regulation

AP Biology energy 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 + +

AP Biology Living economy  Fueling the economy  eat high energy organic molecules (food)  break them down = catabolism (digest)  capture energy in form cell can use  Need an energy currency  a way to pass energy around ATP Whoa! Hot stuff!

AP Biology ATP  Adenosine Triphosphate  modified nucleotide  adenine + ribose + P i  AMP  AMP + P i  ADP  ADP + P i  ATP an RNA nucleotide How efficient! Build once, use many ways

AP Biology Why does ATP store energy? P O–O– O–O– O –O–O P O–O– O–O– O –O–O P O–O– O–O– O –O–O P O–O– O–O– O –O–O P O–O– O–O– O –O–O P O–O– O–O– O –O–O P O–O– O–O– O –O–O P O–O– O–O– O –O–O  Each P i group more difficult to add  a lot of stored energy in each bond  most stored in 3rd P i  ∆G = -7.3 kcal/mole  Close packing of negative P i groups I think he’s a bit unstable… don’t you?  spring-loaded instability of its P bonds makes ATP an excellent energy donor

AP Biology How does ATP transfer energy? P O–O– O–O– O –O–O P O–O– O–O– O –O–O P O–O– O–O– O –O–O energy P O–O– O–O– O –O–O +  Phosphorylation  when ATP does work, it transfers its 3rd P i to other molecules  ATP  ADP  releases energy  ∆G = -7.3 kcal/mole  it destabilizes the other molecule Why is 3rd phosphate like a baaad boyfriend?

AP Biology it’s never that simple! An example of Phosphorylation…  Building polymers from monomers  need ATP for energy & to take the water out C H OH H OHOH C C H O H C + H2OH2O kcal/mol C H OH + C H P + ATPADP -7.3 kcal/mol H OHOH C C H O H C + + C H P PiPi -3.1 kcal/mol “kinase” enzyme

AP Biology glucose C-C-C-C-C-C fructose-6P P-C-C-C-C-C-C-P DHAP P-C-C-C PGAL C-C-C-P 2 ATP 2 ADP Another example of Phosphorylation…  The first steps of cellular respiration  beginning the breakdown of glucose  ATP those phosphates sure make it uncomfortable around here enzyme 1 enzyme 3enzyme 4 enzyme 5 enzyme 6 enzyme 2

AP Biology ATP / ADP cycle A working muscle recycles over 10 million ATPs per second Whoa! Pass me the glucose & oxygen! Can’t store ATP  too reactive  transfers P i too easily  only short term energy storage  carbs & fats are long term energy storage

AP Biology What’s the point?  Cells spend a lot of time making ATP! “The point is to make ATP!” I didn’t HEAR you! Make ATP! That’s all I do all day. And no one even notices!

AP Biology Any Questions??