AP Biology 11/23/2015 The Point is to Make ATP! ATP Making energy!

AP Biology 11/23/2015 Energy needs of life  Organisms are endergonic systems  What do we need energy for?   synthesis (biomolecules)  reproduction  active transport  movement  temperature regulation

AP Biology Transformations between kinetic and potential energy More potential energy. Potential energy converted to kinetic energy. Kinetic Energy Converted to Potential Energy Less potential energy

AP Biology 11/23/2015 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 The two laws of thermodynamics (a) First law of thermodynamics: Energy can be transferred or transformed but neither created nor destroyed. Second law of thermodynamics: Every energy transfer or transformation increases the disorder (entropy) of the universe. (b) Chemical energy Heat co 2 H2OH2O +

AP Biology H / 2 O 2 2 H 1 / 2 O 2 (from food via NADH) 2 H e – 2 H + 2 e – H2OH2O 1 / 2 O 2 Controlled release of energy for synthesis of ATP ATP Electron transport chain Free energy, G (b) Cellular respiration (a) Uncontrolled reaction Free energy, G H2OH2O Explosive release of heat and light energy + How Food Becomes Energy

AP Biology 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 + + digestion synthesis

AP Biology 11/23/2015 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 11/23/2015 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 11/23/2015 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 11/23/2015 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 11/23/2015 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 11/23/2015 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 11/23/2015 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 11/23/2015 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 11/23/2015 Any Questions??