1/28/14 kin 270 class notes- Energy and reactionso Finished off with thiso Energy liberating exergonico Energy consuming Take energy to happen – endergonic- The breakdown of glucoseo Exergonic reactiono Take glucose molecule – breaking that downo Lots of stepso Extract energyo Little bit left in glucose moleculeo Metabolized the whole thing to carbon dioxide and water- Coupled reactiono Exergonic reaction, going from reactions to productso Coupled to adjacent gear o Product from reactants- Exergonic reactionso Occur spontaneouslyo Put ATP into water, left on desktop, break down into ADP and phosphateo Occurs spontaneously- Oxidation-reduction: electron transfer (a coupled reaction)o Transfer of an electrono Release of energyo Gain of energyo Oxidation (“offer”) Loss of electrons Molecule donates electrons to another molecule- Not free e-, often with H+- Oxygen not required (unlike the name implies)- Oxygen is a really strong acceptor of electronso Reduction (“receive”) Gain of electrons Molecule accepts electrons (typically with a H+)- Oxidation and reduction reactions are coupleso Compound A has 2 electrons with it Reducing agento Meets with oxidized compound Bo Electrons transfer from A to Bo In process, A is oxidized (losing electrons)o B is reduced (gaining electrons)o Terms can be confusing…o At the end of the reaction: oxidized compoundo Opposite true of Bo Gained electrons, reduced compound- A Key Electron Carriero Nicotinamide Adenine Dinucleotide (vit B3)o Lot of reactions, this serves as electron carrier Reduced compound, NAD serves as oxidizing agent Compound becomes oxidized NAD becomes reducedo NAD+H+ is a shuttle to next compound (Y) Y gains electrons and protons NAD becomes reduced againo Recyclingo Can do process all over again- Enzymeso Catalysts that regulate the speed of reactionso Reactions would happen very slowly without themo Muscle contraction can happen in mso Lower the activation energy requiredo Factors the regulate enzyme activity Temperature- Optimum temp- Above or below and it will slow down pH- optimum range- most of ours are around neutral (7)o interact with specific substrateso increase metabolism by changing temperature cold water?o Learning structure of enzymes is important Windows into disease Some things that drive cell growth are small enzymes Drug companies:- Find drugs to inhibit enzymes based on shape- Stop tumors/metastasis/etco Enzymes are so specific for substrates- Enzymes lower the energy of activationo Free energy on y axiso Course of reaction on x axiso ATP in jar of water – sit on desk Hydralyzes Amount of energy required would be very high (take a long time)o Start with ATP & Pi, get a certain amount of energy out of those, doesn’t matter if enzyme is there or not- Simplest enzymatic reactiono Many dif reactions enzymes will catalyzeo Stick with ATP analogyo Compounds bindo Substrate with specific shape, reciprocal image to match thato Magic happens!o Enzymes allows products to be generatedo Enzyme changes shape, lower affinity for substrate, releases them- More complex reactiono A& B bind to enzymeo Somehow, it breaks down/synthesizes new products = creates C & D- Nomenclature of enzymeso “ase” suffixo Oxidoreductases Redox reactions (e.g. LDH)o Transferases Transfer elements, P (e.g. PFK)o ATPases Hydrolyze ATP (e.g. myosin)- Bioenergeticso Process of providing energy for all cell functions including movementso Conversion of food (fats, proteins, CHO) into energyo Energy is converted in usable forms: ATP Electrical, mechanical, chemical, potentialo Myosin particularly neat Uses chemical, changes it into mechanical work (movement) Most of that energy is lost as heat- Fuels for human movementso CHO’s 4 kcals/gram glucose; stored as glycogen in muscle and liver, available in bloodo Fats fatty acids; stored as triglycerides in muscle and fat cells; 9 kcals/g subcutaneous; visible to us- abdominal, legs, triceps, etco Proteins Not a primary energy source during exercise, but can be used ifneeded; 4 kcal/gram Largely don’t use them during exercise Progressing toward starvation or at the end of a long exercise session (ex. a 4 hour run – after hour 3 will use protein most likely) Protein can go to krebs cycle and be used for energy- Not an efficient way of doing things- Don’t really want to use it- ATP: cellular energy currencyo Adenine, (tri)phosphate, riboseo 3 phosphates are important breaking of bonds is what gives us energyo measure change in ATP at UMass; muscle fatigue study put leg in magnetic resonance device ATP content of muscles Spectrum Points – concentration of ATP, corresponds to phosphate groups- Hydrolyze ATPo Triphosphate  diphosphateo Then… hydrolysis reaction, release inorganic phosphate molecule In doing so, release tension in molecule, release energy Decent enzyme, harness the energy Muscles; means to cause movement/generate force- ATP-coupled reactionso Many processes use ATPo Intermediate between thingso Energy producing reactions Go through when we talk about glycolysis/KREBs/ETCo Foods coupled to formation of ATPo ATP is formed, floats around cell, harnesses energy in cello Pump calcium around cello Build proteinso Replicate DNAo Harness energy of ATPo Energy for a lot of dif reactions- Three pathways to generate ATPo ATP + Water  (atpases) = ADP + Pio 1st way creatine kinase reaction start exercising, breaking down ATP that will find way to phosphocreatine PCr  Cr (give to ADP) ADP  ATP Reaction tapped into almost immediately Low store in the muscles… ATP/CP only lasts for 5 seconds-10 seconds- Sprints, quick activitieso 2nd way glycolysis- use of glucose- oxidative or nonoxidativeo 3rd way oxidative phosphorylation- much more complex way of making ATP- more efficient- more ATP out of this reactiono Keep in mind Creatine kinase & glycolysis in cytosol Oxidative phosphorylation in the mitochondria- CK reaction basis of Cr supplementationo Premise: increase pool of phospho creatine will allow high intensity workout for longer periods of timeo No definite answer… lots of controversy/disagreement- Bioenergetics: formation of ATPo Anaerobic pathways; (without O2) Creatine kinase reaction PCr Glycolysis (glucose) Occur