Fall 2014 Exam 2 GradesPowerPoint PresentationSlide 3Slide 4Slide 5Slide 6AR4Slide 8The mitochondriaCellular RespirationHow does the cell transfer the energy contained in a glucose molecule into ATP molecules?The cell obtains energy from glucoseWhat happens when a phosphate or ATP molecule binds to a specific site in an enzyme?What causes the structural change in an enzyme?When ATP is hydrolyzed energy is released`Energetic couplingWhat is a reduction-oxidation reaction?What happens when glucose is oxidized?Slide 19Slide 20Slide 21Slide 22Slide 23The Potential Energy of Glucose is Transferred to ATPs in Many Small StepsWe can think about glucose (and fats) as saving accountsHow does the oxidation of glucose take place in a way that support the production of ATP?How does the cell produce ATP?Energetic Coupling in GlycolysisSlide 29Substrate-level phosphorylationOxidative phosphorylationOverview of glucose oxidationSlide 33GlycolysisThe Krebs CycleHow pyruvate enters the matrix?Pyruvate is first converted to Acetyl CoAThe Krebs cycleKrebs CycleSlide 40Slide 41What the cell earns from the Krebs cycle?Because during Glycolysis two molecules of pyruvate are producedSummary of Glucose OxidationWhat has the cell obtained from each molecule of glucose?What happens to the NADH and FADH molecules produced?Figure 3 illustrates two steps in the Krebs Cycle. Which molecule is oxidized / reduced? (note: Ignore the blue arrow)Drops in free energy are couple with the production of ATP, NADH, FADH2What will happen if the final acceptor (oxygen) is not present in the cell?Using poisons researchers figured out the sequence of the molecules in the electron transport chainSlide 51Electron-Transport Chain is composed of four large protein complexes and cofactorsATP SynthaseSlide 54In Figure 3, how and where is the ATP (labeled by the arrow) produced in eukaryotes?FermentationSlide 57How fermentation occurs in humans?In the fungus Saccharomyces cerevisiate (yeast) alcohol fermentation occurs.In cells that are capable, the fermentation pathway turns on when oxygen is unavailable, helping to regenerate NAD+ . When oxygen is present, where is NADH oxidized?The drug 2,4-dinitrophenol (DNP) destroys the proton gradient across the inner mitochondrial membrane by creating holes in the outer mitochondrial membrane and allows protons to escape. What would be the effect of incubating isolated mitochondria in a solution of DNP?Slide 62Fall 2014 Exam 2 Grades•Class Average= 72%•Non-SI Students’ Average= 67%•Attended SI only 1x Average= 72%•Attended SI more than 5x Average= 79%Supplemental Instruction Weekly SessionsMCB 181R (011, 012) Dr. Pimentel Sunday 4:00-4:50pm Manzanita Mohave Residence Hall ** Monday3:00-3:50pm Likins 110 (Likins Residence Hall) ** Tuesday 11:00-11:50am Javelina Room (Park Student Union) Wednesday 10:00-10:50am Sonora Conference Room (Arizona Sonora Residence Hall) **4:00-4:50pm Maricopa Piano Room (Maricopa Residence Hall) ** Thursday8:30-9:15am Sonora Conference Room (Arizona Sonora Residence Hall) **11:00-11:50am Sonora Conference Room (Arizona Sonora Residence Hall) **5:30-6:20pm Sonora Conference Room (Arizona Sonora Residence Hall) ** Friday 11:00-11:50am Pima Lodge Room (Pima Residence Hall)** **Students, please check in at the residence halls’ front desk.AR4AR4A. Assertion is true; Reason is true; Reason is the correct explanationB. Assertion is true; Reason true; Reason is NOT the correct explanationC. Assertion is true; Reason is falseD. Assertion is false; Reason is trueE. Assertion is false; Reason is falseAssertion ReasonIncreasing the temperature of the cells by more than 25 degrees will accelerate the rate of the enzymatic reaction.BecauseHydrogen bonds are broken by an input of energy in the form of heat.AR4AR41. Assertion is true; Reason is true; Reason is the correct explanation2. Assertion is true; Reason true; Reason is NOT the correct explanation3. Assertion is true; Reason is false4. Assertion is false; Reason is true5. Assertion is false; Reason is falseAssertion ReasonAbrupt changes in pH in the cell affects the rate of an enzymatic reaction.BecauseHydronium and hydroxide ions interrupt the ionic bonds in between charged amino acids.300The mitochondria•Mitochondria is an organelle virtually found in all eukaryotic cells.•It has two membrane.•The interior membrane is infolded–This create sac like structures called cristae–The region inside the inner membrane but outside the cristae is called the matrix.–Most of the enzymes responsible for the Krebs cycle are located in the matrix.Cellular RespirationHow does the cell transfer the energy contained in a glucose molecule into ATP molecules?•The cell will carry out a sequence of small chemical reactions to efficiently transfer the energy from glucose to ATP•This process will reduce energy lost as heatOverall chemical reaction for glucose conversion to ATP: C6H12O6 + 6O2 + ADP 6CO2 + 6H2O+ ATPThe cell obtains energy from glucose12Cellular RespirationPotential Energy- is stored energy Kinetic Energy- is energy in motionAdenosine triphosphate (ATP)What happens when a phosphate or ATP molecule binds to a specific site in an enzyme?–The shape of the enzyme changes–The activity of the enzyme changes with the change of shape.–This can trigger the synthesis of second messenger molecules.–Or contribute to the initiation of a phosphorylation cascade.What causes the structural change in an enzyme?When ATP is hydrolyzed energy is released`Energetic coupling•The exergonic and endergonic reactions are couple.•This allows that the endergonic reaction becomes exergonic when the substrate or enzyme are phosphorylated.What is a reduction-oxidation reaction?•Reduction–oxidation reactions (redox reactions)–involve the loss or gain of an electron. •The atom that loses one or more electrons is oxidized,•The atom that gains one or more electrons is reduced. –Oxidation events are always coupled with a reduction–an electron donor is always paired with a reactant that acts as an electron acceptor.•Electrons can be transferred completely from one atom to another or:–Electrons can shift their position in covalent bonds.What happens when glucose is oxidized?•When glucose burns, the change in potential energy is converted to kinetic energy in the form of heat.•686 kcal of heat is released when one mole of this sugar is oxidized.If the glucose’s potential energy will be