Fall 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 Sessions MCB 181R 011 012 Dr Pimentel Sunday 4 00 4 50pm Manzanita Mohave Residence Hall Monday 3 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 Thursday 8 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 Assertion Reason AR4 Increasing the temperature of the cells by more than 25 degrees will accelerate the rate of the enzymatic reaction Because Hydrogen bonds are broken by an input of energy in the form of heat A Assertion is true Reason is true Reason is the correct explanation B Assertion is true Reason true Reason is NOT the correct explanation C Assertion is true Reason is false D Assertion is false Reason is true E Assertion is false Reason is false Assertion Abrupt changes in pH in the cell affects the rate of an enzymatic reaction Reason Because Hydronium and hydroxide ions interrupt the ionic bonds in between charged amino acids 1 Assertion is true Reason is true Reason is the correct explanation 2 Assertion is true Reason true Reason is NOT the correct explanation 3 Assertion is true Reason is false 4 Assertion is false Reason is true 5 Assertion is false Reason is false AR4 30 0 The 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 Respiration How does the cell transfer the energy contained in a glucose molecule into ATP molecules Overall chemical reaction for glucose conversion to ATP C6H12O6 6O2 ADP 6CO2 6H2O ATP 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 heat The cell obtains energy from glucose Cellular Respiration Adenosine triphosphate ATP Potential Energy is stored energy 12 Kinetic Energy is energy in motion 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 converted to kinetic energy in one single step The cell will release so much energy in the form of heat that the sugar will ignite itself Assertion Most of the biochemical reactions that occurs in the cells are endergonic Reason Because For endergonic reactions to proceed energy is required The energy will come directly from the glucose molecules A Assertion is true Reason is true Reason is the correct explanation B Assertion is true Reason true Reason is NOT the correct explanation C Assertion is true Reason is false D Assertion is false Reason is true E Assertion is false Reason is false AR4 30 0 Assertion Reason The figure shows an Because For this reaction to proceed it is endergonic reaction necessary to hydrolyze a molecule of ATP AR4 A Assertion is true Reason is true Reason is the correct explanation B Assertion is true Reason true Reason is NOT the correct explanation C Assertion is true Reason is false D Assertion is false Reason is true E Assertion is false Reason is false 30 0 The Potential Energy of Glucose is Transferred to ATPs in Many Small Steps We can think about glucose and fats as saving accounts When you deposit money in a savings account you get a paper saying that you have money deposit in the bank However for you to buy something you need to translate that money in your savings account into cash How does the oxidation of glucose take place in a way that support the production of ATP four step process 1 Glucose is broken down to a three carbon compound called pyruvate 2 Pyruvate is process to form a compound called acetyl CoA 3 Acetyl CoA is oxidized to CO2 4 Compounds that were reduced in steps 1 2 and 3 are oxidized in reactions that lead to the production of ATP How does the cell produce ATP Energetic Coupling in Glycolysis Remember why the phosphate groups are added we must first destabilize the glucose molecule After it is unstable F 16 BP then almost every subsequent reaction will be exergonic Assertion Although the conversion of glucose to pyruvate contains both endergonic and exergonic steps overall the process is exergonic Reason Because Pyruvate is a higher energy molecule when compared with glucose 1 Assertion is true Reason is true Reason is the correct explanation 2 Assertion is true Reason true Reason is NOT the correct explanation 3 Assertion is true Reason is false 4 Assertion is false Reason is true 5 Assertion is false Reason is false AR4 30 0 Substrate level phosphorylation Oxidative phosphorylation Overview of glucose oxidation The molecule is being split Glycolysis Energy produced 4 ATP Energy spent 2 ATP Net energy gained