Biochemistry: Concepts and Connections (2nd Edition)
2nd Edition
ISBN: 9780134641621
Author: Dean R. Appling, Spencer J. Anthony-Cahill, Christopher K. Mathews
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 3, Problem 18P
Consider the degradation of glucose to pyruvate by the glycolytic pathway:
Glucose + 2ADP + 2Pi + 2NAD+
Calculate
17. For part (b) of this problem, use the following reduction potentials, free energies, and nonequilibrium concentrations of reactants and products:
Consider the last two steps in the alcoholic fermentation of glucose by brewer's yeast:
Pyruvate + NADH + 2H+
a. Do you predict that
b. Calculate the nonequilibrium concentration of ethanol in yeast cells, if
pH = 7.4 and 37o C when the reactants and products are at the concentrations given above.
c. How would a drop in pH affect
d. How would an increase in intracellular CO2 levels affect
e. How would an increase in intracellular CO2 levels affect
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
When grown anaerobically on glucose, yeast (S. cerevisiae) converts pyruvate to acetaldehyde, then reduces acetaldehyde to
Pethanol using electrons from NADH.
Write the chemical equation for the reaction that reduces acetaldehyde (CH3CHO) to ethanol (CH3CH2OH).
The table provides the standard reduction potential, E', of the relevant half-reactions.
Half-reaction
Acetaldehyde + 2 H+ + 2e¯ → ethanol
NAD+ + 2H+ + 2e¯ → NADH + H+
E'° (V)
-.197
-.320
Calculate the equilibrium constant, K'eq, at 25.0 °C for the reaction that reduces acetaldehyde to ethanol.
K'e
×10
=
eq
The half-reactions involved in the lactate dehydrogenase (LDH) reaction and their standard reduction potentials are (see attached)). Calculate ΔG at pH 7.0 for the LDH-catalyzed reduction of pyruvate under the following conditions: (a) [lactate]/[pyruvate] = 1 and [NAD+]/[NADH] = 1. (b) [lactate]/[pyruvate] = 160 and [NAD+]/[NADH] = 160. (c) [lactate]/[pyruvate] = 1000 and [NAD+]/[NADH] = 1000. (d) Discuss the eff ect of the concentration ratios in Parts a–c on the direction of the reaction.
The phosphorylation and oxidative decarboxylation of oxaloacetate by inorganic phosphate (Pi) to make phosphoenolpyruvate and carbon dioxide is endergonic under intracellular conditions. It is characterized by this equation:
Oxaloacetate + Pi ←→ Phosphoenolpyruvate + H2O + CO2 ΔG’ = +24.6 kJ/mol
The synthesis of GTP from GDP and inorganic phosphate (Pi) in solution is endergonic under intracellular conditions, and it is characterized by this equation:
GDP + Pi ←→ GTP + H2O ΔG’ = +30.5 kJ/mol
Write a new net thermodynamically coupled reaction equation that describes the synthesis of phosphoenolpyruvate from oxaloacetate using the hydrolysis of GTP to power the reaction and calculate the new net ΔG’ of this reaction. Show all of your work.
Chapter 3 Solutions
Biochemistry: Concepts and Connections (2nd Edition)
Ch. 3 - Prob. 1PCh. 3 - Given the following reactions and their...Ch. 3 - The decomposition of crystalline N2O5...Ch. 3 - The oxidation of glucose to CO2 and water is a...Ch. 3 - Prob. 5PCh. 3 - In another key reaction in glycolysis,...Ch. 3 - Assume that some protein molecule, in its folded...Ch. 3 - When a hydrophobic substance like a hydrocarbon is...Ch. 3 - It is observed that as temperature is increased,...Ch. 3 - Suppose a reaction has Ho and So values...
Ch. 3 - Prob. 11PCh. 3 - Prob. 12PCh. 3 - Prob. 13PCh. 3 - Undergoing moderate activity, an average person...Ch. 3 - The major difference between a protein molecule in...Ch. 3 - Prob. 16PCh. 3 - Prob. 17PCh. 3 - Consider the degradation of glucose to pyruvate by...Ch. 3 - a. Consider the malate dehydrogenase reaction,...Ch. 3 - Bovine ribonuclease folds with Ho = -280 kJmol-1...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biochemistry and related others by exploring similar questions and additional content below.Similar questions
- Acetyl CoA + 2H* + 2e = pyruvate + COASH E = -0.48 V Ubiquinone + 2H* + 2e = Ubiquinol E" = +0.04 V Consider the redox rxn wherein a pair of e passes from pyruvate to ubiquinone. Calculate the change in standard Gibbs free energy (kJ/mol). Report answer to two decimal places.arrow_forwarda) The following reaction which is catalyzed by aldolase: Fructose-,6-bisphosphate (FBP) + Glyceraldehyde 3-phosphate (GAP) + Dihydroxyacetone phosphate (DHAP) AG for this reaction is 22.8 kJ mol'. In the cell at 37°C, AG for this reaction is -5.9 kJ mol". Determine the ratio [GAP][DHAP]/[FBP]arrow_forwardA new drug, Proinebrium, that reduces Kcat (Ki = 2.0 uM) has been developed to treat ethylene glycol poisoning. (1) What concentration of Proinebrium is required to achieve 50% inhibition of ethylene glycol metabolism by alcohol dehydrogenase when the concentraion of ethlyene glycol in the blood is 50 uM?arrow_forward
- Proline racemase catalyzes the conversion between L-proline and D-proline. The Km and kcat for this reaction are 0.15 M and 550/sec respectively. If the enzyme concentration is 1.45 X 10-5 mmole/ml what is the Vmax of this reaction?arrow_forward(a) Consider the oxidation of malate to oxaloacetate by NAD*: malate + NAD+ → oxaloacetate + NADH + H+ In yeast mitochondria, where the pH = 8.1, this reaction is exergonic only at low oxaloacetate concentrations. Assuming a pH = 8.1, a temperature of 37 °C, and the steady-state concentrations given below, calculate the maximum concentration of oxaloacetate at which the reaction will still be exergonic. malate + NAD*→ oxaloacetate + NADH + H* lactate + NAD →→ pyruvate + NADH + H+ half reaction Pyruvate + 2H+ + 2e → lactate Pyruvate + CO₂ + H + 2e → malate Intracellular steady state concentrations: malate = 410 μM; NAD = 20.0 mM; pyruvate = 3.22 mM; NADH = 290 μM; AG=+29.7 kJ/mol AG¹ = +25.1 kJ/mol E° (V) - 0.190 - 0.330 lactate 1.1 mM CO₂ = 15.5 torrarrow_forwardFor the following aspartase reaction in the presence of the inhibitor hydroxymethylaspartate, determine Km and whether the inhibition is competitive or noncompetitive. You have to plot thegraph on the graph paper and also by using excel.[S] V, No Inhibitor V, Inhibitor Present(molarity) (arbitrary units) (same arbitrary units) 1 x 10-4 0.026 0.0105 x 10-4 0.092 0.0401.5 x 10-3 0.136 0.0862.5 x 10-3 0.150 0.1205 x 10-3 0.165 0.142arrow_forward
- The equilibrium constant for the hydrolysis of the peptide alanylglycine (Gly-Ala in the reaction from Part B) by a peptidase is K = 9.0 × 10² at 310 K. Calculate AG for this reaction. Express the Gibbs free energy to three significant figures. AG = Submit ΠΑΠΙ ΑΣΦ Request Answer ? kJ/mol Keq [Gly] [Ala] [Gly-Ala]arrow_forwardThe reactionPyruvate-(aq) + NADH(aq) + H+(aq) → lactate-(aq) + NAD+(aq)where NAD+ is the oxidized form of nicotinamide adenine dinucleotide, occurs in muscle cells deprived of oxygen during strenuous exercise and can lead to cramp. Calculate the biological standard Gibbs energy, ΔrG⊕, for the reaction at 310 K given that the thermodynamic standard reaction Gibbsenergy ΔrGΘ = -66.6 kJ mol-1.arrow_forwardThe redox half reaction Oxaloacetate + 2H+ + 2e− → Malate has a standard reduction potential value of 0.166 V. Calculate the free energy (ΔG°′) for the following reaction: Malate + NAD+ → Oxaloacetate + NADH + H+arrow_forward
- If a 0.1 M solution of glucose 1- phosphate at 25 °C is incubated with a catalytic amount of phosphoglucomutase, the glucose 1-phosphate is transformed to glucose 6-phosphate. At equilibrium, the concentrations of the reaction components are Calculate Keq and ΔG′° for this reaction.arrow_forwardThe turnover number of the enzyme fumarase that catalyzes the reaction, Fumarate + H20 ===→ L-malate, is 2.5 x 103 S - l and Km = 4.0 X 10- 6 mol/L. Calculate the rate of conversion of fumarate to L-malate if the fumarase concentration is 1.0 x 1 0 - 6 mol/L and the fumarate concentration is 2.04 x 10- 4 mol/L.arrow_forwardThe standard Gibbs (free) energy of reaction (A,Gº') of the following reaction is equal to zero (at 25 °C and pH 7) pyruvate + aspartate Pyruvate, aspartate and L-alanine are mixed each at a concentration of 1 mM, without oxaloacetate. Calculate the molar concentrations of each compound when the reaction reaches equilibrium. oxaloacétate + L-alaninearrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage Learning
Biochemistry
Biochemistry
ISBN:9781305577206
Author:Reginald H. Garrett, Charles M. Grisham
Publisher:Cengage Learning
Enzyme Kinetics; Author: MIT OpenCourseWare;https://www.youtube.com/watch?v=FXWZr3mscUo;License: Standard Youtube License