Purchase Solution

Biophysics - Calculating deltaG

Not what you're looking for?

Ask Custom Question

In one day the average person secretes about 2.5 litres of gastric juice into the stomach. The pH of the cells in the stomach lining that perform the secretion is about 7 (the same as for all cells) and the pH of the stomach is about 1. Thus, H+ ions must be moved against an H+ gradient. The free energy change for moving molecules against a gradient is:

^G = R T lne(C2/C1) (where ^ = delta)

where C2 is the greater concentration. If the process of pumping H+ ions is 20% efficient, how many moles of ATP are used each day to secrete gastric juice? How many kilograms could be lifted one meter (20% efficiency) wiht this energy?

Purchase this Solution
Solution Summary

This solution is provided in 250 words. It uses pH, ideal gas constant, and absolute temperature to find deltaG, and calculates moles.

Solution Preview

The H+ concentrations have to be calculated from the pH:

[H+] = 10 ^ -pH (10 to the power of minus pH)

e.g If the pH is 6, [H+] = 10^-6

Now calculating C2/C1 and finding its natural logarithm (ln) should be easy. I get an answer of about 14.

R is the ideal gas constant, which is 8.31 ...

Purchase this Solution
Free BrainMass Quizzes
The Heart

This quiz test the understanding of the heart and some of its parts. It is important to understand how the heart functions and what makes it function.

The Transfer of Energy in an Ecosystem

This quiz will assess your knowledge of how energy is transferred in an ecosystem and the different levels of trophic organization.

Basic Concepts in Neuroscience

This quiz provides a review of the basic concepts in neuroscience.

Birth 101

Do you know about childbirth? Find out with this quiz.

Labor Comfort Measures

Do you know how to comfort someone in labor?

View More Free Quizzes
Related BrainMass Solutions

  • Gibbs Free Energy: ATP-coupled reactions:

    + ATP deltaG = - 12.5 KJ/mol b) Pi + Fructose --> Fructose-6-phosphate + H2O deltaG = + 15.9 KJ/mol ATP + H2O --> ADP + Pi deltaG = - 30.5 KJ/mol ATP + Fructose --> ADP + Fructose-6-phosphate deltaG = - 14.6 KJ/mol Solution includes

  • DeltaG Values from Reactions and Non-standard Conditions

    145206 DeltaG Values from Reactions and Non-standard Conditions 1) If the overall deltaG of the following reaction is -5.3Kcal/M and we know that the deltaG for the conversion of ADP + Pi ---> ATP is +7.3Kcal/M, what must the deltaG be for the conversion

  • Spontaneous Reactions and Entropy

    deltaS isn't the right criterion for spontaneity, deltaG is. deltaG=deltaH - T * deltaS Although delta S is negative for this case, deltaH is highly negative because it is highly exothermic, so deltaG is negative and the reaction is spontaneous.

  • Absolute entropy, free energy and spontaneity

    b) Use the values from a to calculate DeltaG° for the following reaction at 25°C. c) Explain fully whether this reaction spontaneous or non-spontaneous at 25°C?

  • Free energy change of a reaction

    Therefore standard state deltaG = deltaH - T*deltaS = -2043.8 - 298*0.1 = -2073.6 (kJ/mol) b. deltaG can now be calculated by changing the temperature: deltaG = deltaH - T*deltaS = -2043.8 - 1000*0.1 = -2143 (kJ/mol).

  • equilibrium concentration from thermodynamic data

    Please see the attached file for detailed solution. 1) first find the the standard state free energy change: deltaG = deltaH - T* deltaS 2) find the equilibrium constant Keq: deltaG = -RTln(K) 3) setp up the equilibrium constant equation.

  • Calculating the equilibrium constant

    40749 Calculating the equilibrium constant Calculating the equilibrium constant. I have had trouble with this problem. The EXACT question asks: Calculate the equilibrium constant at 298K for the following equation.

  • Gases, Temperature, Current and Reactions

    -DeltaG = RTlnK we can find this answer, but first we nee to find DeltaG for this reaction the same as in the previous question and plug it into the above equation.

  • Moles of ATP from Oxidation of Ethanol

    (with an assumed efficiency of 37%) Glucose ---> 2 ethanol + 2 CO2 deltaG°= -55,000 cal/mol Glucose + 6 O2 ---> 6C02 + 6H20 deltaG° = -686,000 cal/mol Given the info below, what is the number of moles of ATP that could

View More Related Solutions