Use your dominant hand Open and close the pin (with your thumb and forefinger) as many times as you can for 20 seconds while holding the other fingers straight out! Repeat for 5 more continuous trials! Repeat for the non-dominant hand What happened as time went on? How did you hands feel at the end? Was there a difference in dom and non- dom hands? Why will your muscles recover in about 10 min? The total amount of energy in the universe is constant! Energy cannot be created or destroyed but only converted to one form into another! Activation Energy Amount of E required to break chemical bonds Entropy = Randomness and Chaos Universe favours Entropy think of how messy your room gets! In all Rxns Energy and Entropy are needed! Spontaneous Human Combustion? Energy of products more than reactants Photosynthesis Light energy converted to stored chemical energy C 6 H 12 O 6 Every molecule of glucose contains 2870kJ Photosynthesis Energy of products is less than reactants Free energy is released! Cellular respiration The energy from glucose is released and harnessed into ATP at a controlled rate! Cellular Respiration The Goal of C.R. is to create ATP from Glucose! See handout! Four main parts... 1) Glycolysis 2) Pyruvate Oxidation 3) Krebs Cycle (Citric Acid Cycle) 4) Electron Transport Chain Redox Reactions Substrate Level Phosphorylation Oxidative Phosphorylation These rxns occur frequently throughout the cellular respiration pathways! Energy metabolism in cells involves oxidation reactions. Oxidation involves the transfer of an electron from a molecule, which is said to be oxidized, to another molecule, which is said to be reduced. An oxidation cannot occur without a corresponding reduction. They are PAIRED reactions. Many important redox reactions in cells require the presence of coenzymes. The redox reactions of cellular respiration commonly involve the following coenzymes: 1) NAD: Nicotinamide adenine dinucleotide NAD e H + NADH + H + *the second H+ dissolves into cytosol * 2) FAD: Flavin adenine dinucleotide FAD + 2e H + FADH 2 LEO the lion says GER L ose E lectrons O xidized! SAYS... G ain E lectrons R educed! Reduced means that the overall positive charge of the molecule has decreased (due to accepting the electons!) A mechanism forming ATP directly in an enzyme-catalyzed reaction ATPase ADP + P i + 31 kJ/mole ATP This is called Phosphorylation... The opposites is called Dephosphorylation A single muscle cell uses 600 million ATP per minute The body consumes its own mass in ATP per day via constant recycling! ATP formed in-directly Uses redox rxns (see previous slides) NADH FADH 2 These molecules harvest energy and transfer it to ATP by the end of Cellular Resp. A glucose is broken down into 2 Pyruvate molecules Brief overview... hill.com/sites/ /student_view0/ chapter25/animation__how_glycolysis_w orks.htmlhill.com/sites/ /student_view0/ chapter25/animation__how_glycolysis_w orks.html Occurs in the cytoplasm Anaerobic (doesnt need oxygen!) See handout!! Glycolysis cont. Recall that there are 2 GAP per glucose. Balance sheet for ~P bonds of ATP: How many ATP ~P bonds expended? ________ How many ~P bonds of ATP produced? (Remember there are two 3C fragments from glucose.) ________ Net production of ~P bonds of ATP per glucose: ________ 2 4 2 Glucose + 2 ADP + 2 P i + 2 NAD + 2 Pyruvate + 2 ATP + 2 (NADH + H + ) 2.2% of E from glucose is transferred to ATP via Glycolysis. This might be good enough for some micro-organisms but not larger species like ourselves! A much more detailed look...W4b29rg&feature=related Page 115 #1-7 Occurs in the Matrix See P 100 for a great diagram General Equation... CoA = coenzyme A 2 Pyruvate + 2 NAD CoA 2 acetylCoA + 2 NADH + 2H + +2CO 2 Acetyl CoA then enters the Kreb Cycle!! In mitochondrion Mostly on inner membrane Many enzymes, coenzymes and other molecules are in an organize pattern on the inner membrane. Brief Overview...hill.com/sites/ /student_view0/ chapter25/animation__how_the_krebs_c ycle_works__quiz_1_.html More depth! jTM1qnPMjTM1qnPM Note where H 2 O is used and CO 2 is released! By the end of the Krebs Cycle (thru Steps 1- 3) the entire glucose molecule is consumed. 6C get converted to 6 CO 2 along the way! HARNESSED ENERGY (NET)! 4 ATP (2 Glycolysis, 2 Krebs) 12 reduced coenzymes: 2 NADH (Glycolysis) 2 NADH (Pyruvate Oxidation stage) 6 NADH (Krebs) 2FADH 2 (Krebs) Occurs on the inner membrane of mito Transports electrons (from NADH and FADH 2 ) thru a series of redox rxns that release free energy. This free energy is used to pump H+ protons into the inner membrane space of the mitochondria This creates an electro-chemical gradient that is a source of free energy which is used to create ATP! Overheads Visuals... hill.com/sites/ /student_view0/ chapter25/animation__electron_transpor t_system_and_atp_synthesis__quiz_1_.ht mlhill.com/sites/ /student_view0/ chapter25/animation__electron_transpor t_system_and_atp_synthesis__quiz_1_.ht ml WbKOW0u8&feature=relatedWbKOW0u8&feature=related Oxygen is the final acceptor of electrons that pass thru the ETC!! Its high electronegativity pulls the electrons through the ETC Electrons fall (like a skydiver)...this energy pumps H+ ions into the inner membrane space so they can fall back into the matrix and make ATP! Protons move through a Proton Channel and ATP synthase to produce ATP molecules Oxidative Phosphorylation!! Electrochemical Gradient must be maintained (by eating!) or ATP production stops! NADH diffuses thru the inner membrane via the glycerol-phosphate shuttle (P105) NADH passes electrons to FAD to make FADH 2 NADH can also pass electrons to NAD+ in the matix via the aspartate shuttle (less common!) In simplified terms NADH pumps 3 H+ ions across...therefore creating 3 ATP molecules! FADH 2 enters the ETC at Q...therefore only pumping 2 H+ ions across and making 2 ATP molecules! Theoretical and Actual Yields Actual...depends on environment (ie temp) Theoretical 36 ATP Actual yield is less...heat loss, H+ ions leaking...Approx 30 ATP?? Aerobic C.R. Is approx 32% efficient See page 110 and page 114 To review all 4 Steps...See these interactive animations... ents/Biology/Bio231/ents/Biology/Bio231/ Page #8-18 An organisms Metabolic rate is the amount of energy consumed at a given time and a measure of the overall rate of C.R. Rxns! Phosphofructokinase (catalyzes step 3 of Glycolysis) controls C.R. It is activated by ADP and inhibited by ATP NADH inhibits pyruvate decarboxylase and prevents Acetyl-CoA from forming An organisms Metabolic Rate is the amount of energy consumed by an organism in a given time. PROs Broken down into individual A.A.s in the body. First stage of this is deamination (removal of amino group as ammonia NH 3 ), a waste. The remaining parts of the A.A.s are converted into components of glycolysis or Krebs cycle Triglycerides are digested into glycerol and fatty acids Glycerol can be converted into glucose by gluconeogenesis or into DHAP Fatty Acids are transported to the matrix, undergo beta-oxidation (conversion into acetyl CoA...enters the Kreb cycle) Occurs during vigorous exercise when O 2 is in short supply. Very inefficientbut quick! After glycolysis, the pyruvic acid is converted into lactic acid. L.A. is toxic and must be removed by delivering O 2 to the cellsthis is why you suck wind after a sprint!!! Elite athletes can tolerate higher L.A. levels in their blood. Eg. Lance Armstrong 4x the normal threshold! This process is also used to make cheese and yogurtbacteria do the work! Can be increased by training A measure of aerobic fitness Maximum volume of oxygen (mL) that the cells can remove from the bloodstream in one minute per kg of body weight. 35 mL/kg/min is average A very painful test....run/bike faster and faster! Can be improved with training Genetics! Decreases with age com/watch?v=FSL1jk wmWcscom/watch?v=FSL1jk wmWcs Occurs in cytoplasm of yeast cells. After glycolysis, pyruvic acid is converted to CO 2 and alcohol. Ethanol could be a valuable, clean burning fuel for industry and transportation. Overheads The energy that fuels life on earth cycles between P.S. and C.R. The products of each process become the substrates for the other. HW Page 124 #1-12 out.com/library/c al/ucrockport.htmout.com/library/c al/ucrockport.htm