Giving you the energy you need!

Giving you the energy you need!

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

Universe favours entropy (pg. 63-64) Randomness and chaos Smaller, more stable molecules Even distribution of matter and energy Blame your messy room on entropy! In all reactions, energy and entropy are both involved! Net increase in entropy in the universe

Is it possible? see text pg. 6, Table 2 pg. 92, paragraph 1.

Energy capable of doing work. In this case: Chemical energy potential energy stored in chemical bonds

Free energy of products more than reactants Ex: Photosynthesis Light energy converted to stored chemical energy in C 6 H 12 O 6 Every molecule of glucose contains 2870kJ

Photosynthesis

Free energy of products is less than reactants Free energy is released from the reactants -- increasing entropy! Ex: Cellular respiration Free energy stored in the bonds of glucose is released and then trapped and stored in the bonds of ATP (at a controlled rate)!

Cellular Respiration

Goal: to create ATP using released energy from glucose! See handout Four main parts... (occuring in) 1) Glycolysis (cytoplasm) 2) Pyruvate Oxidation (mitochondrial matrix) 3) Krebs Cycle/Citric Acid Cycle (mitochondrial matrix) 4) Electron Transport Chain (inner mitochondrial membrane)

Redox Reactions (reduction-oxidation) Phosphorylation Substrate Level Phosphorylation (during glycolysis and the Krebs cycle) Oxidative Phosphorylation These reactions occur 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 + + 2 e - + 2 H + NADH + H + *the second H+ dissolves into cytosol * 2) FAD: Flavin adenine dinucleotide FAD + 2e - + 2 H + FADH 2

LEO the lion says GER Lose Electrons Oxidized! SAYS... Gain Electrons Reduced!

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 opposite is Dephosphorylation A single muscle cell uses 600 million ATP per minute The body consumes its own mass in ATP per day via constant recycling!

A glucose is broken down into 2 Pyruvate molecules Brief overview... http://highered.mcgrawhill.com/sites/0072507470/student_view0/c hapter25/animation how_glycolysis_works.h tml Occurs in the cytoplasm Anaerobic (doesn t need oxygen!) See handout!! And pg. 98

Free energy? Endergonic? Exergonic? Phosphorylation? Substrate-level?

REDOX reaction memory aid? Anaerobic vs aerobic? Four stages in aerobic respiration? Glycolysis reactant? Glycolysis products? Energy carriers?

Source: Pearson Education

6-Carbon 3-Carbon (x2) Change in isomer (G3P) glucose ATP Hexokinase ADP glucose-6-phosphate fructose-6-phosphate ATP Phosphofructokinase ADP fructose-1,6-bisphosphate Glycolysis Phosphoglucose Isomerase Aldolase (DHAP) glyceraldehyde-3-phosphate + dihydroxyacetone-phosphate Triosephosphate Isomerase Glycolysis continued

glyceraldehyde-3-phosphate Glycolysis cont. Recall that there are 2 G3P per glucose. NAD + + P i NADH + H + Glyceraldehyde-3-phosphate Dehydrogenase 1,3-bisphosphoglycerate ADP Phosphoglycerate Kinase ATP 3-phosphoglycerate 2-phosphoglycerate Phosphoglycerate Mutase H 2 O Enolase phosphoenolpyruvate ADP Pyruvate Kinase ATP pyruvate

Balance sheet of ATP chemical bond energy: Bonds broken/energy used: How many ATP are converted to ADP? Bonds formed/energy acquired: How many ATP are formed from ADP? (Remember there are two 3C fragments from glucose.) Net energy gain (#ATP formed) per glucose: 4 2 2

Reactants: Glucose + 2 ADP + 2 P i + 2 NAD + Products: 2 Pyruvate+2H + 2 ATP + 2 NADH ***For more detail on each step see pg. 98 or watch this http://www.youtube.com/watch?v=o5emw4b29rg&feature=related

Efficiency: 2.2% Percentage of the total free energy in glucose that is harnessed as ATP during Glycolysis Not good enough. So the Krebs Cycle and electron transport chain continue to process the pyruvate

http://www.youtube.com/watch?v=efglznwfu 9U HW: Page 115 #1-7

Source: Pearson Education

Source: Pearson Education

Occurs in the mitochondrial matrix

General Equation... (CoA = coenzyme A) 2 Pyruvate + 2 CoA + 2 NAD + 2 acetylcoa +2CO 2 + 2 NADH + 2H + **Acetyl CoA = 2-carbon molecule (other C was lost in CO 2 ) - becomes a reactant for the Krebs Cycle!!

Source: Pearson Education

Occurs in the mitochondrial matrix Many enzymes, coenzymes and other molecules organized on the inner membrane. Overview... http://highered.mcgrawhill.com/sites/0072507470/student_view0/chapter25/anima tion how_the_krebs_cycle_works quiz_1_.html

phosphoenolpyruvate

http://www.daviddarling.info/encyclopedia/c/citric_acid_cycle.html

http://www.purposegames.com/game/0e38f b1b/info

By the end of step 4 of the Krebs Cycle the entire glucose molecule is consumed. All 6 carbon atoms are lost as CO 2 along the way (3 per pyruvate) Products? 3 CO2, 2 ATP, 6 NADH, 2 FADH2 More depth! : pg. 102 of textbook http://www.youtube.com/watch?v=a1djtm1qnpm Note where H 2 O is used and CO 2 is released!

NET HARNESSED ENERGY 4 ATP (2 Glycolysis, 2 Krebs) 12 reduced coenzymes: 2 NADH (Glycolysis) 2 NADH (Pyruvate Oxidation stage) 6 NADH (Krebs) 2FADH 2 (Krebs)

Source: Pearson Education

Outer membrane Intermembrane space Inner membrane

Occurs on the inner membrane of mitochondria Transports electrons (from NADH and FADH 2 ) thru a series of redox rxns (in 2 s!)

****Mobile electron carriers

Enzymes in order of increasing electronegativity so free energy is released at each step. Electrons flow downhill to lower free energy

O2 is the most electronegative step! Thus is the final electron acceptor Its high electronegativity pulls the electrons through the ETC

The free energy released from electrons powers proton pumps that carry H+ into the inter membrane space This creates an electro-chemical gradient (potential energy!)

Protons move through a Proton Channel and ATP synthase This powers the conversion of ATP from ADP and Pi Oxidative Phosphorylation ***NOTE: the electrochemical gradient must be maintained (by eating) or ATP production stops

NADH and FADH 2 store harvested energy along the way ATP formed indirectly at the end of the electron transport chain (final stage of aerobic respiration

NADH diffuses thru the inner membrane via the glycerol-phosphate shuttle NADH passes electrons to FAD to make FADH 2

NADH enters at the start of the ETC so it pumps 3 H+ ions along the way creates 3 ATP molecules! FADH 2 enters the ETC at Q and so only pumps 2 H+ ions Creates 2 ATP molecules!

http://highered.mcgrawhill.com/sites/0072507470/student_view0/c hapter25/animation electron_transport_syst em_and_atp_synthesis quiz_1_.html http://www.youtube.com/watch?v=0lcwbko W0u8&feature=related

Step coenzyme yield ATP yield Source of ATP Glycolysis preparatory phase Glycolysis pay-off phase Oxidative decarboxylation of pyruvate Krebs cycle Total yield 2 2 NADH 6 2 NADH 4 6 NADH 18 2 FADH 2 4 4 2 36 ATP Phosphorylation of glucose and fructose 6-phosphate uses two ATP from the cytoplasm. Substrate-level phosphorylation Oxidative phosphorylation Each NADH produces net 2 ATP due to NADH transport over the mitochondrial membrane Oxidative phosphorylation Substrate-level phosphorylation Oxidative phosphorylation Oxidative phosphorylation From the complete oxidation of one glucose molecule to carbon dioxide and oxidation of all the reduced coenzymes.

Overall efficiency ~ 32% Ie. 32% of free energy in glucose is harnessed Compare to 2.2% for just glycolysis! Theoretical VS Actual Yield 36 ATP VS ~30 ATP Actual yield varies due to env. Conditions H+ ions leaking H+ ions used by cell for other thing

See pg 110 and pg 114 To review all 4 Steps...See these interactive animations... http://www.science.smith.edu/departments/ Biology/Bio231/ Page 115 - #8-18

Page 115 #1-7 Page 115 #8, 10-16