Problem 4The cytoplasmic ratio of the tripeptide glutathione, Glu-Cys-Gly (GSH), to its axidized dimer GSSG is amarker of oxidative stress in a cell.glutathione (aS)The standard reduction potential for GSSG + 2H" + 2e= 26SH is E"=-0.23 V.(a) NADPH, a reducing agent closely related to NADH, is present in the cytoplasm of cells (E" = -0.32 V).Under standard state conditions, is NADPH capable of reducing GSSG?NHOH OH N-THOH OPONADPH(b) Assume that the steady-state ratio of GSH/GSSG = 50:1 and that the total concentration of GSH +GSSG = 12 mM. At what pH would the reaction between GSSG and NADPH be thermoneutral (i.e.,AG = 0)? Assume (NADPH) = 3 mM and (NADP') = 0.03 mM; Te 298K.

Reduction is the process of accepting electrons or protons i.e. a molecules is said to have been…

Answered: Problem 4 The cytoplasmic ratio of the…

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter18: Glycolysis

Section: Chapter Questions

Problem 17P

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Begining with 1 M concentrations of each reactant and product at pH=7 and 25.0 degrees C, calculate the K'eq (to one decimal point) of the reaction Pyruvate + NADH+H+ <=> Lactate + NAD+.Note the temperature of this reaction will not affect the standard reducton potential delta E'o in the table 13-7b. please provide a comprehensive explanation with each step taken.
Question (2rarate nusCollagenase is an endopeptidase that digest native collagen in the triple helix region. The diagram below shows the kinetic plot of collagenase with varied substrate concentration. Plot collagenase activity in response to substrate concentration and find approximate values for Vmax and Km. (please indicate your assumption/s accordingly for this question) 0,04 0,035 0 luM) 0,03 O 200 (uM) 0,025 X 270 (uM) 0.02 A 350 (uMI 0,015 0.01 0,005 On 10 20 30 50 60 Collagenase [pg/ml] Collagenase activity [mM/min]
Question: A. To explore the consequences of coupling ATP hydrolysis under physiological conditions to a thermodynamically unfavorable biochemical reaction, consider the hypothetical transformation X⟶Y, for which Δ?′°=20.0 kJ/mol. What is the ratio of [Y]/[X][Y]/[X] at equilibrium? B. Suppose XX and YY participate in a sequence of reactions during which ATP is hydrolyzed to ADP and Pi. The overall reaction is X+ATP+H2O⟶Y+ADP+Pi Calculate [Y]/[X] for this reaction at equilibrium. Assume that the temperature is 25.0 °C and the equilibrium concentrations of ATP, ADP, and Pi are 1.00 M each. C. We know that [ATP], [ADP], and [Pi] are not 1.00 M under physiological conditions. Calculate [Y]/[X] for the ATP‑coupled reaction when the values of [ATP], [ADP], and [Pi] are those found in rat myocytes. Metabolite Concentration in rat myocytes (M) ATP 8.05x10-3 ADP 0.93x10-3 Pi 8.05x10-3
Begining with 1 M concentrations of each reactant and product at pH=7 and 25.0 degrees C, calculate the K'eq of the reaction Pyruvate + NADH Lactate + NADH+H+. Note the temperature of this reaction will not affect the standard reducton potential delta E° in the table 13-7b.
Question:- Two enzymes, acetate kinase and phosphotransacetylase, convert acetate [CH3C(O)O–] and ATP to acetyl phosphate and ADP (acetate kinase reaction) then acetyl phosphate and CoASH (coenzyme A) into acetyl-CoA and inorganic phosphate (Pi ; phosphotransacetylase reaction). What is the ΔG°' for the synthesis of acetyl-CoA from acetate, CoASH, and ATP by this enzyme pair?
P3D.2 In biological cells, the energy released by the oxidation of foods is stored in adenosine triphosphate (ATP or ATP“).The essence of ATP's action is its ability to lose its terminal phosphate group by hydrolysis and to form adenosine diphosphate (ADP or ADP): ATP* (aq) + H,O() → ADP* (aq) + HPO (aq) + H,O*(aq) At pH = 7.0 and 37°C (310K, blood temperature) the enthalpy and Gibbs energy of hydrolysis are A,H =-20kJ mol and A,G=-31 kJ mol", respectively. Under these conditions, the hydrolysis of 1 mol ATP“(aq) results in the extraction of up to 31kJ of energy that can be used to do non- expansion work, such as the synthesis of proteins from amino acids, muscular contraction, and the activation of neuronal circuits in our brains. (a) Calculate and account for the sign of the entropy of hydrolysis of ATP at pH = 7.0 and 310K. (b) Suppose that the radius of a typical biological cell is 10µm and that inside it 1x 10ʻ ATP molecules are hydrolysed each second. What is the power density of…
Please answer fast The equilbrium constant (Keq) under standard conditions for the hydrolysis of ATP is 200,000 M. This would suggest the reaction is: 1. proceeding in reverse direction 2. proceeding in forward direction 3. in equilibrium However, this does not take into consideration the concentration of substrates/products within the cell. This is can be calculated by determining the reaction quotient, Q by: [ATP] x [Pi] / [ADP] [ATP] + [Pi] / [ADP] [ADP] x [ATP] / [Pi] [ADP] x [Pi] / [ATP] Biochemical reactions commonly involve the transfer of groups from ATP. What is one of the products of pyrophosphate cleavage from ATP? AMP Adenosine ADP Inorganic phosphate Q5-6. The hydrolysis of ATP is often coupled to other reactions. For example: Phosphoenolpyruvate (PEP) + H2O → Pyruvate + Pi (ΔG'° = -63.1 kJ/mol) ATP + H2O → ADP + Pi (ΔG'° = -30.5 kJ/mol) (The standard free-energy changes for the reactions are indicated in brackets) Q5. Given the information above, what is the…
Initial rate data for an enzyme that obeys Michaelis–Menten kinetics areshown in the following table. When the enzyme concentration is 3 nmolml-1, a Lineweaver–Burk plot of this data gives a line with a y-intercept of0.00426 (μmol-1 ml s). (a) Calculate kcat for the reaction.(b) Calculate KM for the enzyme.(c) When the reactions in part (b) are repeated in the presence of 12 μM ofan uncompetitive inhibitor, the y-intercept of the Lineweaver–Burk plotis 0.352 (μmol-1 ml s). Calculate K′I for this inhibitor.
Kinetic Parameters of Enzyme-Catalyzed Reactions TABLE 12-1 The Values of KM, Keat, and Keat/KM for Some Enzymes and Substrates Enzyme Substrate KM (M) 9.5 x 10-5 1.2 x 10-² 2.6 x 10-2 2.5 x 10-2 4.4 x 10-1 8.8 x 10-2 6.6 x 10-4 Acetylcholinesterase Carbonic anhydrase Catalase Chymotrypsin Fumarase Urease Acetylcholine CO₂ HCO₁ H₂O₂ N-Acetylglycine ethyl ester N-Acetylvaline ethyl ester N-Acetyltyrosine ethyl ester Fumarate Malate Urea 5.0 x 10-6 2.5 x 10-5 2.5 x 10-2 Keat (S-¹) 1.4 x 104 1.0 × 106 4.0 × 105 1.0 X 107 5.1 x 10-2 1.7 × 10-1 1.9 X 10² 8.0 x 10² 9.0 × 10² 1.0 X 104 Keat/KM (M¹s¹) 1.5 × 108 8.3 x 107 1.5 x 107 4.0 X 108 1.2 x 10-1 1.9 2.9 × 105 1.6 × 108 3.6 X 107 4.0 X 105 Which enzyme is the most catalytically efficient? Which substrate does chymotrypsin bind to most tightly (assume k_₁ >> K₂)? Is fumarate or malate a better substrate of fumarase? Is it possible to have a kcat/KM of greater than 1 x 10⁹ M-¹ s-¹? Why or why not?
Standard redox potentials Eo' for some common compounds in biochemistry: Eo' (Volt) + 0,81 +0,42 + 0,25 12 O₂ + 2 H+ + 2 e NO3 + 2 H+ + 2 e 2 cyt c (ox) + 2 e 2 cyt b (ox) + 2 e Pyruvate + 2 H+ + 2 e* NAD + 2 H+ + 2 e Acétoacétate + 2 H+ + 2 e (2) acétoacétate + NADH + H+ H₂O NO₂ + H₂O 2 cyt c (red) 2 cyt b (red) Lactate (3) 2 cyt c (ox) + 2 cyt b (red) NADH + H+ B-hydroxybutyrate + 0,08 - 0,19 With the help of the above table, determine the spontaneous direction of the following reactions in the standard conditions. Justify your answers by calculating the Gibbs (free) energy of reaction in each case. (1) pyruvate + ß-hydroxybutyrate -0,32 - 0,35 lactate + acétoacétate B-hydroxybutyrate + NAD+ 2 cyt c (red) + 2 cyt b (ox)
Question:: Acyl CoA synthetase hydrolyzes ATP to AMP + PPI (pyrophosphate) as part of the activation of fatty acids to fatty acyl-CoA. Explain the role played by the enzyme inorganic pyrophosphatase in this reaction (in the activation of fatty acids to fatty acyl CoA) in the space provided below.
Begining with 1 M concentrations of each reactant and product at pH=7 and 25.0 degrees C, calculate the K'eq of the reaction Pyruvate + NADH Lactate + NADH+H+. Note the temperature of this reaction will not affect the standard reducton potential

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