Question

3. The reaction in gluconeogenesis that converts 3-phosphoglycerate to 1,3-bisphosphoglycerate is at right. The AGC for this reaction is +18.9 kJ/mol. H-C-OH o HC - H-C-OH H2C 0 ATP ADP P-O 0 3-phosphoglycerate 1,3-bisphosphoglycerate a) What is the concentration of 3-phosphoglycerate under standard state conditions? b) In the hepatocyte, this reaction is near equilibrium. What is the AG in the cell? c) What is the ratio of products-to-reactants for this reaction in the hepatocyte? Assume the temperature is 25°C (298 K). Show all work for full credit. d) The flow of this reaction is controlled only by the availability of its reactants and products - i.e., it is an uncontrolled step. Other control steps in the pathway determine whether the overall flux through this step is in the forward or reverse direction. If the cell happens to be undergoing glycolysis, so that the amount of ATP increases and the amount of ADP decreases, would this reaction as written above shift left or right? e) Would this shift oppose or enhance the flow of glycolysis?

Answer 1

312247 Standard Estate condition concentration ofre reactanto & producto are at concentration. So, unden standard state conditions concentration of a -Phosphs glycorate will be IM (b) we know, where, a energy of som coutant noik TE .G= AG + RT ln Q G = Gibb's free chya range reaction at nowstandard conditions AG = Gibb's free energy change of reaction at standard condition physilogical cal pH=7 R = Gan 8.314 I Absolute temper inature Q = Reaction austient At equilibrium 4 Q = 0 in hepatocyte te AG in the cell AG equal to lo Since inkopatoryte at equilibrium reaction nearly 69074 [ here, => 18900 4 =- 83144 X2988 enkeq mos keq= Eauilibrium 0903 in sal Ľ at equilibrium (c) we know, : -RT ln keq T=298k moting comtan- = +18.9 KT mol =) en keq =) en keqa 18900 8.314 X298 -763 18900 1 mmol C:: IKS =10001] =) keq=é 7.63 = 41868104 keq = 4.86 4104

terve the reaction is 3 phospho glycenate tapp (376) → 13- bisphospho glycevase (1) BPG ADP 0 Reactant =keq ATP to L Equilibrium contant Producto [1,3 BPG [ ADP] Keg [SPG] [Amp] Poro dueta 4.800x10 Reactant (2) when increases then according La chatelieron for incible to regain the equilibrium the extra Atp should be consumed. so, forward reaction will be favored ATP f will form more product So, reaction will shift to right (e) Simee here atp is using by the reaction (;)& in glycolypin ATP in produced. So, due to high Atp by the reaction of (1), the night shift of reaction (1) will enhance the flow of glycolpis, to decreare above