Syllabus for ChE 301

INTRODUCTION TO CHEMICAL ENGINEERING THERMODYNAMICS

Fall, 2011, 2:10 – 3:00p in Carpenter 101

Prerequisites: ChE 201, ChE or BE major

Instructor: Bernard J. Van Wie        

Office: EE/ME B57 Phone: 509-335-4103 Office Hours: Tu 11a – 12 noon, Th. 1 – 2p, appointment, or by e-mail: bvanwie@che.wsu.edu

 

Teaching Assistant: Kat Tran

Phone: 617-412-5599; Time & Location: M, W 6 – 8p; F 3:15 – 5p in Dana 215, or by e-mail: giao.tran@email.wsu.edu

 

Text: Introduction to Chemical Engineering Thermodynamics by Smith, Van Ness and Abbott (McGraw-Hill, 7th ed.; 6th ed. will work)

Yes

 

Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: http://www.che.wsu.edu/%7Ebvanwie/Classes/301_fall_2005/SYLLABUS_FOR_CHE_301_files/miller13.jpg

Picture: Crude Oil Vacuum Tower - BP Cherry Point Refinery, Blaine, WA

Topical Outline: Clicking on the “Chapters” will lead you to supplementary notes developed by Prof. Emeritus Reid Miller and Prof. Bernie Van Wie.  Found going to the Voiland School Website http://www.voiland.wsu.edu/, clicking on Faculty & Staff, clicking on Bernard Van Wie, and then on ChE 301 – Introduction to Chemical Engineering Thermodynamics.

Chap. 1 & 2 Introduction and 1st Law - Aug. 22-Sept. 2

Chap. 3 & 4 Volumetric Properties and Heat Effects – Sept. 2 – 12

Chap. 5 2nd Law - Sept. 12-21

Help Session: Th., Sept. 22, 7p

Exam 1 - Sept. 23       Practice_Exam_I_2008_2006_2005.pdf

Practice_Exam_Ib_2008_2003_1999.pdf

Chap. 6 & 7 Thermodynamic Properties and Flow Processes - Sept. 26-Oct. 10

Chap. 10 - 12 Phase Equilibrium & Solution Thermodynamics - Oct. 10-28

Help Session: Sun., Oct. 30, 7p

Exam 2 – Oct. 31       Practice_Exam_II_2008_2005_2003.pdf

                                    Practice_ExamII_2008_2005_2003_No_Solutions.doc

Stagewise Processing Stagewise Processes - Nov. 2-18

·                     Introduction to Pro II:  Pro II Basics Tutorial; Introduction to Pro II

·                     Pro II Flash, Distillation, Gibbs Reactor Modules

·                     Distillation Tutorial in HYSYS

Chap. 13 Chemical-Reaction Equilibrium – Nov. 28 – Dec. 7

·                     Pro II Flash, Distillation, Gibbs Reactor Modules

·                     Tutorial on Equilibrium Reactors in HYSYS

Review - Dec. 9

Possible Help Session: Th. Dec. 15, 7p

Final Exam – Fri. Dec. 16 (7:00 - 10:00 a.m.)

                                    Practice Finals

                                    Practice Final - No Solutions

Links to the following:

Homework Assignments

Some Basic Definitions

Course Objectives:

1. Students develop a fundamental understanding of the basic principles of chemical engineering thermodynamics. (memory, comprehension)

2. Students can examine and select pertinent data, and solve thermodynamics problems. (application, analysis, synthesis)

3. Students can select and/or evaluate problem solution methods, for example, between analytic and numerical solution techniques. (synthesis, evaluation)

4. Students can give examples of important applications of thermodynamics in chemical engineering processes. (memory, comprehension)

5. Students can evaluate their own solutions and those of others to find and correct errors. (evaluation)

6. Students can apply critical thinking while working in a structured team environment to solve problems, including open-ended problems. (analysis, synthesis)

7. Students can assess their team problem-solving processes to improve these processes. (evaluation)

8. Students can describe in written and oral form any of the concepts implied in the above objectives.

Special Features:

Active Learning – Teams of four students will be formed, self-selected but subject to veto by the professor.  Roles of team leader, recorder, technical specialist, and reflector should rotated by the group during the semester.  These groups will be used in three ways.  First, in-class discussions will be by group.  Second, most homework assignments are group; for individual assignments you may talk with your group, though you  must turn in your own individual work.  Third, a team design project will be assigned during the semester.  Information on organization and operation of teams is available through this link.

Relationships to Chemical Engineering PracticeEvery attempt will be made to relate the information developed in class to the real world of engineering design operations.  Students will be asked to identify different applications of thermodynamics that appear to be important in specific chemical processing operations.

Learning Styles and LevelsLesson plans will be developed to incorporate different learning styles and different levels of learning (see information on Bloom's Taxonomy).  Course objectives have been developed to involve a range of learning levels, as indicated in parentheses above.

Policies and Procedures:

1. Course Grade

45%                 Hour Exams

30%                 Final Exam

25%                 Homework & Design Projects

Grades of 90, 80, 70 and 60% are cutoffs for A's, B's, C's and D's.  However, depending on relative exam difficulty, cutoffs may be slightly below these.  Grades of "+" and "-" will be used to differentiate performance.

2. Exams

Two exams will be given plus a Final Exam during Finals Week.  If one of the in-class exams is missed, with an authorized university excuse, a makeup will be given.  All exams will be "open book", "open notes", "open homeworks" and "open reference materials".

3. Academic Integrity

Misrepresentation of a student's involvement in any required academic work will result in the instructor invoking the academic dishonesty policies of the university.  This could result in an "F" grade for the course.  Collaboration is expected for group activities including projects and group homeworks.  Also, interaction with your group is encouraged on individual homeworks; however, the final solutions should be worked out individually.  Clearly, there should be no interaction during an examination period.  Instructions for each assignment should be followed.  If in doubt, ask the instructor of teaching assistant.

4. Homework and Design Projects

Homework problems and a design project will be assigned throughout the semester (with due dates).  Homework is due at the beginning of class on the assigned due date.  Homeworks turned in after class up to 5:00p, will receive 25% off while that turned in by 8:00a the following morning will receive 50% off.  No credit will be given after that.  Group and Individual (I) and assignments will be given, but I always encourage group discussions before solving any problem.  Obviously, copied assignments or computer programs are not acceptable.  Homeworks must be a clear presentation of the problem and its solution that can be understood fully by another engineer.  Homeworks should include:

A problem statement with a diagram (0.5 pts)

Approaches and equations used for the solution (varies)

Values with units used for the solution, e.g., P = 10 atm (1 pt)

The answer clearly indicated – underlined or boxed with appropriate units (0.5 pts)

A discussion of your role and contribution on the assignment: team leader, recorder, technical specialist, or reflector (0.25 pts each).

Implications of the answer, e.g., adding the kinetic energy term for the inlet vapor results in a 0.1% change in the solution value.  Since engineering answers rarely are significant beyond three digits this implies that unless special high velocity circumstances apply that kinetic energy can be neglected from this point forward (0.5 pt extra credit up to 1.5 pts max for each valid implication)

 

Up-to-date computer graphics, linear regressions, etc. (varies depending on appropriateness for a given problem)

Paper: computer printouts of solutions on Mathcad, etc. or Engineering paper – no college ruled or spiral notebook paper; use only one side of paper (-0.5 pts if you use the wrong kind of paper)

Separate group work from individual assignments

Students with Disabilities:

Reasonable accommodations are available for students with a documented disability. If you have a disability and may need accommodations to fully participate in this class, please visit the Disability Resource Center (DRC). All accommodations MUST be approved through the DRC (Washington Building, Room 217). Please stop by or call 509-335-3417 to make an appointment with a disability specialist.

ChE 301 – Homework Assignments:

Assignment -- Problems -- Due Date; (I) indicates individual solutions required

  1. Chapter 1 & 2 - 1.5, SP1, 12(I), 20 & 2.1, 27, 28, 34(I) – Sept. 2
  2. Chapter 3 & 4 – 3.4, 19, 33, 38(m)(I), 4.3, 4.10(e), 4.21(z), 4.49(I) – Sept. 12
  3. Chapter 5 – 5.4, 7(I), 19, 21, 26, SP2 – Sept. 21
  4. Chapter 6 & 7 – 6.8, 23, 36, 45(I), 87(j); 7.4, 19(e), 35(e)(I), SP 3, SP4(I)  – Oct. 5
  5. Chapter 10 & 11 – 10.1 b,c,d,f, 10.2a(I) - 5pt EC by Mathcad, 7, 17b; 26a(I), SP5, SP6(I), 11.17, 19, 28, 27(I) 10pt EC (only) by Mathcad – Oct. 17
  6. Chapter 12 – 12.3a(I), 15(methanol + benzene), 30, 45a,b(I), SP5, SP6(I), SP8  – Oct. 28
  7. Design Project: Simplified VLE Calculations – Due Nov. 18
  8. Stagewise Processes – Dec. 2
  9. Chapter 13.1c, 13(I) – Pro II Gibbs Reactor, and by hand, Sp11 – Dec. 9

 

Other Interesting Web Sites

History of Chemical Engineering

Chem-E Tools

Weights and Measurements

Conversion of Units

Periodic Table

Temperature Measurement

NIST Chemistry WebBook

 

Some Basic Definitions

System - that portion of the universe set aside for study

Surroundings - the environment - the rest of the universe

Boundaries - walls - separate system from surroundings

Closed system - constant mass - impermeable boundaries - energy can cross boundaries

Open system - mass and energy can cross boundaries - some permeable or semi-permeable boundaries

Isolated system - constant mass and energy - impermeable, rigid, adiabatic boundaries

Adiabatic walls - prevent thermal equilibrium - no heat

Diathermal walls - instant thermal equilibrium

Dimensions - mental concepts used to distinguish between opposing sense perceptions (e.g., mass, length, time, temperature, etc.)

Units - scales used to quantify dimensions (e.g., g, lb, ft, s, K, etc.)

Measurable properties - concepts suggested by sense perceptions relating to internal aspects of a system (e.g., temperature, volume, etc.)

Derived properties - concepts which arise in analysis through convenience of definition (e.g., enthalpy, entropy, chemical potential, etc.)

Extensive properties - depend on the extent of the system (volume, mass, internal energy, etc.)

Intensive properties - do not depend on extent of the system (e.g., molar volume, density, specific internal energy, temperature, etc.)

State (of a system) - specified by a unique set of intensive properties

Equilibrium - a state of absolute rest - no tendency to change state - no fluxes of heat, mass, or momentum

Process - change in the state of a system - isothermal (const. T), isobaric (const. P), isometric (const. V), etc.

Cycle - series of processes leading back to the initial state of the system

Temperature - the property which tells us whether systems are in thermal equilibrium

Heat - energy in transition across the boundaries of a system due to a temperature difference

Work - energy in transition across the boundaries of a system due to a driving force other than T, and not associated with mass flow

State functions - depend only on the state of a system and not its past history (e.g., U, H, S, etc.)

Path functions - related to changes in state of a system - depend on how these processes take place (e.g., Q, W, E(flow), E(gen))

 

 

Special Problems Related to Bioengineering

 

SP 1 – Due date: Sept. 2

It is common to state that the energy content of human food is only the calories consumed, but considerable energy is involved in getting the food from its source to the eater.

 

It is reported1 that while the world’s human population has grown from 107 to 7x109 over the last 10,000 years, the energy used to feed the world population has grown by a factor of 5x103 from 8x103 kcal per person each day.  How many calories are now used daily to feed each person? 

Comment on the causes of the added calories since the actual intake is about 2500 kcal per day.

 

1Clark ME, “Adriane’s Thread”, St. Martin’s Press, New York, 1989, p 102, as quoted at http://telstar.ote.cmu.edu/environ/m3/s3/all_ene_sys.htm

 

SP 2 – Due date: Sept. 21

The core temperature of the body should be maintained relatively constant at 37oC regardless of the environment. Exposure to cold for extended periods will require extra energy intake and the heat transfer will generate extra entropy.

 

Consider treating severely burned humans by cooling their body in a air or water bath at 15oC for 12-20 hours.  Since more heat will be lost to the surroundings than under normal conditions, there will need to be augmentation of the patient’s energy intake. 

 

Given the data below, estimate:

a) The extra required rate of energy input,  , in kcal/h

b) The rate of extra entropy generation, , in kcal K-1 h-1, for such a patient, regardless of the energy source. 

c) Suggest ideas for putting in this energy.

 

Note:  

Consider the typical patient to be 70 kg mass and 1.75 m in height, so the empirical formula for surface area can be used:  

The rates of heat transferred from the blood system to the skin and from the skin to the bath can be calculated by heat transfer formulae.  An estimate of the rate in such a bath is  with a skin temperature of 25oC while the normal rate  when the skin temperature is 34oC.

 

SP 3 – Due date: Sept. 30

Living systems use energy for many functions. The heart of humans does work to circulate blood. This problem explores using easily measured quantities to obtain the fraction of total body energy converted in circulating blood at various exercise conditions

 

Consider the work that the human heart does when pumping blood and its relation to oxygen consumption at rest and when exercising.  The heart consists of two chambers, the right ventricle that sends the blood to the lungs (pulmonary) and the left ventricle which sends the blood to the rest of the body (systemic).  The blood pressure of the left ventricle is denoted PS while that of the right ventricle is denoted PP.  The volume of blood ejected at each beat is the difference of the volume of blood taken in by the ventricles, or the stroke volume, S.  The rate of work, or power, for the heart to circulate blood is the frequency of heart beats, f, times the sum of PV work by the ventricles for each beat, W, i.e., power =  .  It has been found that under a variety of conditions,. The origin of the body’s energy is oxidation of carbohydrates, fats, and proteins by oxygen taken into the body.  The energy released per liter of oxygen is identified as E.  The part of this energy consumed by the heart to circulate blood is identified as η.  The total rate of oxygen consumption in the body is Ω.

Show that the relationship for the rate of cardiac output of blood, Q, in terms of the stroke volume of the heart and the quantities given above is  where Ω is the total rate of oxygen consumption by the body.

 

SP 4  Due date: Sept. 30

Thermodynamic property relations, especially partial derivatives, hold for all systems whose properties can be defined. Biochemicals are often polymeric, and even elastomeric, and the relevant state properties are not all the same as those for normal fluids. This exercise explores the different properties for elastomers, and demonstrates how some experimental observations can be leveraged to predict behaviors under other conditions

 

Consider a rubber band.  The variables of its state are length, L, stress, t, and temperature, T.  Thermodynamics can take some state information about a system and predict other behaviors, principally through signs on partial derivatives.  A series of experiments and analysis with a large rubber band can illustrate the procedure. 

First, our knowledge of the chemical structure of elastomers is that there are chains with crosslinks at intervals so that the chains between the crosslinks are able to take on many conformations as in the left figure.

When the length, L, is changed, say at constant temperature, T, the chains are stretched, so the number of conformations is reduced, lowering the entropy, S, as in the right figure.  The partial derivative characterizing this process is .

Next, do an experiment.  Slowly stretch the rubber band; increasing L at fixed T takes increased stress, t.  The partial derivative characterizing this process is . 

Another experiment is, with the band pressed against your upper lip, quickly pull on the band.  It should feel warm.  The result of this adiabatic (~isentropic) process gives . 

 

From these relationships and some mathematics, certain predictions of behavior can be made for situations. 

a) Stretch the rubber band to a fixed L hold it while heating.  What happens to the stress?

b) Put a weight on the band and heat.  What happens to the weight?

 

SP 5  Due date:  Oct. 17

Living systems function with semipermeable membranes that allow some components to pass through, but not others. This problem explores the thermodynamics and modeling via the osmotic virial equations for blood hemoglobin and cell walls

 

Consider the situation of red blood cells containing hemoglobin (MW ~ 68000) at a concentration of 0.3 M.  Water passes through the cell walls, but the hemoglobin cannot.

 

a) Ignoring the presence of other substances inside & outside of the cell membrane, prove that there would be a flow of water into the cell at ambient conditions.

b) To stop the flow of water, show that the fundamental equilibrium relations would require increased pressure on the inside of the cell. 

c) Write a relation for the pressure difference across the cell membrane, , and estimate the pressure assuming a binary ideal solution inside the cell and pure water outside the cell.

d) Real binary solutions are often described by the second osmotic virial equation

where  is the molar concentration of hemoglobin and  is the second osmotic virial coefficient, which is a measure of the interaction between pairs of solute particles in the solvent medium.  (Recall that the 2nd virial coefficient of the virial equation of state measures the pair interactions in vacuum.)  If the osmotic pressure, , at body temperature of 37oC is found to be 0.83 MPa, obtain the value of .

e) Red blood cells will rupture under such an osmotic pressure, so Nature arranges things to obviate this by changing the solution outside the cell by addition of a different impermeant.  Suppose the added solute is glucose (MW ~ 180).  If the measured osmotic pressure for 0.7 M glucose is 20 bar, estimate the glucose concentration outside a red blood cell to balance the pressure from 0.3M hemoglobin inside the cell.

 

SP 6  Due date:  Oct. 17

Protein molecular structure has two general forms, native (folded) and unfolded. In solution, these two forms will be in reaction equilibrium, with equal activities of the species at the melting temperature, Tm. This extensive problem applied the thermodynamics of reactions to develop relations and obtain calculations of thermodynamic properties as functions of several variables

 

Protein denaturation can be considered as a reaction between the native species and the unfolded species, .  The “melting” point, , is given as the temperature when equimolar concentrations are found at equilibrium.  This temperature can be changed by pH, pressure, added denaturant, or added salt1.  For lysozyme (MW = 14.313 kDa), calorimetric measurements have been reported2:

1. The heat effect to fully unfold the protein in 2 mL of a pH = 4 solution at a concentration of 1  at  = 78 oC is 0.0755 J.

2. The difference in partial molar heat capacities of the species, independent of T, is2  

 

Using these data and thermodynamic relations, solve the following problems.

a) What is the Gibbs energy difference of the system with native and unfolded species at78oC?

b) Show that at 78oC, the molar enthalpy and entropy differences of the species are , and,  .

c) Show that the Gibbs energy and enthalpy of unfolding as functions of T are  and  where  is a temperature at which the properties of unfolding are known.  Suggest why  might be a convenient .

d) Using the relations of part c, calculate the molar Gibbs energy, enthalpy and entropy differences at pH = 4 and T = 23 oC.  Is energy or entropy “driving” the protein to fold at this temperature?

e) Prove that the ratio of unfolded to folded species concentrations is .

f) The relationship Δ from  has been found2 when pH is used to change .  From this, what is the relationship for  and ? 

g) Using the relations and data above, plot the ratio of unfolded to folded species concentrations as a function of (1/T) from 20oC to 100oC when pH = 4.

h) Add to your plot for part g the ratio of species concentrations when the pH has been adjusted to pH = 1, giving  = 43oC.

i) Lysozyme has four disulfide bonds that constrain the structure.  Cooper et al.2 have modified the wild protein by removing one of the S-S bonds and measuring the change in .  They find that the relationship of part f above, for Δ with  when varied by pH, still holds, even though  can be as low as 23oC at pH 2.5 for the mutant.  Prove this indicates that the reduction of stability by disulfide bond removal is purely entropic.

j) The volume change of denaturating lysozyme has been obtained3  Δ .  Is its sign reasonable for the different structures?  If this protein is the same as that for parts a - h, at what pressure would the protein melt when T = 23oC?

 

1. Haynie DT, “Biological Thermodynamics, 2nd Ed.” Cambridge University Press, Cambridge, UK, 2008, chapter 2.

2. Cooper A, Eyles SJ, Radford SE, Dobson CM, J. Mol. Biol. 1992 225 939-943.

3. Sasahara K, Sakurai M, Nitta K, Proteins 2001 44 180–187.

 

SP 7 – Due date: Oct. 28

A statement of the Second Law of Thermodynamics is that doing something in opposition to Nature takes work. The reversible work is the minimum and its amount depends on the conditions. Separation and purification of fluid mixtures, such as for chemicals, do not happen spontaneously, so work must be put in and there will be an associated heat effect.

 

a) Derive the expression for the minimum reversible isothermal-isobaric work to completely purify 1 mol of a solute from a solvent in an ideal solution.

b) Calculate the required work for mole fractions from 10-1, 10-2,  . . .  to 10-9 at 300 K. 

c) Derive the relation for the heat effect and calculate the amount for the separation process of parts a) and b).

d) Comment on how solution non-idealities would affect the work and heat effects.

e) Since such separations are done for chemicals from pharmaceuticals to sewage, comment on the economics for recovery of dilute products and the wisdom of dilution before concentration.

 

SP 8  Due date:  Oct. 28

Purification of biochemicals is often done through dissolution in solvents followed by precipitation. Effective solvent selection is important for such processing. This problem examines thermodynamic property relations and modeling for estimating biochemical solubility in solvents using hydrocortisone as an example

 

Pharmaceuticals and other biochemicals are often processed by dissolution in solvents and then precipitated for purification.  Toxicity, waste disposal, and economics have a significant impact on solvent selection.  Further, choosing a solvent by exhaustive experimental search is inefficient, so thermodynamic models have been developed to leverage a minimum of data for finding new and alternative solvents for biochemical processing.

 

a) Derive the following expression for the solubility of a solute, i, that is pure in the solid form, in a solvent, j:

where  is the enthalpy of melting the solute at the melting temperature, , and  is the solute activity coefficient in the solvent.  Assume that the heat capacities of the solid and liquid solute are equal.  For compounds sparingly soluble in a solvent k, this may often be taken as the value at infinite dilution,.

b) Using the following data, estimate the solubility of hydrocortisone (2) in hexane (1) and n-butyl acetate (1’) from ideal solution and with the solubility parameter method for estimating activity coefficients.  Compare these estimates with the experimental values.

34.87

485.5

25.37

0.293

-5.43

 

Solvent

Hexane (1)

14.8

131.6

-18

n-butyl acetate (2)

16.5

132.5

-7.4

c) An alternative approach is to use a measured solubility of the solute in a reference solvent, j, and ratios of activity coefficients to estimate the solubility in another solvent, k.  Derive the fundamental relation for this method

Note that the pure solute properties are not needed here.

Reference : Poling BE, Prausnitz JM, O’Connell JP, Properties of Gases and Liquids, 5th ed., McGraw-Hill, 2000

 

SP 9  Due date: Dec. 9

Knowing the preference for biocompounds to dissolve or partition in liquid phases is important in bioprocessing. A biothermodynamic approach to estimating relative solubilities of amino acids in aqueous solutions and organic solvents is explored in this problem

 

When placed in systems containing immiscible, or partially miscible, liquids such as water with organic solvents, biochemicals will partition between the two liquid phases.  The partition coefficient,, is defined as the ratio of concentrations of a solute i in an organic solvent, , to that in an aqueous phase, , .  This concept can be used even if the organic and water are not immiscible.  In all cases, the value of  would also be a measure of the relative solubility of a solid solute in the solvent to that in water since the chemical potential of the solute is determined by the solid form and the difference in activity coefficients of the solutes in the solvents will cause different solution concentrations.

A further useful way to determine the relative partitioning of biocompounds, such as amino acids, is the ratio of the partition coefficient of the acid of interest to that of glycine, which is the same as the selectivity relative to glycine, .  This quantity can be related to the differences in Gibbs energy of transfer of the solute, , from water to an organic solvent,.

 Damordaran and Song1 give values for  at 37oC for many amino acids to different organics (kcal mol-1) while Hammes2 gives values for transfer from water to aqueous urea at 25oC; some are

Amino Acid

Side Chain

N-methylacetamide

ethanol

hexane

8M Urea

Glycine

H

0

0

0

0

Alanine

CH3

-0.67

-0.80

0.44

-0.07

Leucine

(CH3)2CHCH2

-2.55

-2.15

-2.80

-0.38

Phenylalanine

C6H5CH2

-3.02

-2.88

-2.59

-0.70

Tyrosine

HO-pC6H4CH2

-3.58

-2.67

-

-0.73

Using these data, order the solubilities of the amino acids in the different solvents and discuss the impact of the side chain structures on the values.

 

1Damodaran S, Song, KB, J Biol Chem, 1986, 261, 7220-7222.

2Hammes, GG, “Thermodynamics and Kinetics for the Biological Sciences”, Wiley-Interscience, 2000, p 57.

 

SP 10  Due date:  Dec. 9

Certain proteins can bind to DNA chromosomes for the purpose of regulating functioning. Using the thermodynamics of binding two different proteins, this problem illustrates how properties can suggest differences in ligand function

 

Certain proteins can bind to DNA chromosomes for the purpose of regulating functioning.  A protein, identified as WT1, has a domain containing zinc that binds to DNA in order to suppress a particular type of kidney tumor.  A protein of very similar structure, identified as EGR1, also binds to the same DNA site and is involved in regulating cell proliferation.  Research suggests that there may be an important regulatory link between these two proteins. 

The amounts of bound protein have been studied for these proteins as a function of temperature.  Some results are given below.  The uncertainties in ln K are ± 0.1.

Determine the standard state enthalpies and entropies for binding and comment on what these values suggest about the molecular binding processes for WT1 and EGR1.

Protein

WT1

EGR1

ln K @ 4oC

19.6

20.4

ln K @ 11oC

20

20

ln K @ 27oC

20.9

19

 

 

SP 11 – Due date: Dec. 9

Living systems couple unfavorable reactions to favorable reactions to make biochemicals that would not normally form. This problem treats the unfavorable phosphorylation of glucose by coupling to the favorable ATP hydrolysis to form ADP

 

An important biochemical reaction is the phosphorylation of glucose

C6H12O6 + H3PO4  C6H13O9P + H2O                      (1)

 

a) Show that the standard state Gibbs energy and enthalpy of this reaction are 12 and 1 kJ mol-1 respectively.  Does this suggest that the reaction is favorable or not?

b) The concentrations of the species are actually not 1 M. They are given below.  Under such conditions, show that the Gibbs energy change for the reaction is unfavorable.

c) Living systems overcome this barrier by coupling this reaction with a reaction involving dissociation of adenosine triphosphate (ATP) to adenosine diphosphate (ADP) that is coupled to the phosphorylation reaction by removing the H2O and providing the phosphoric acid.  Using the tabulated values compute the standard state and actual state property changes for the reaction

ATP + H2O  ADP + H3PO4                        (2)

Is this reaction favorable?

 

d) If the two reactions occur in the same system,

C6H12O6 + ATP C6H13O9P + ADP            (3)

what are the standard state and solution Gibbs energy changes and the standard state enthalpy change?

 

The standard state properties (1 M, 1 atm, 298 K, pH 7.0, pMg 3.0, ionic strength 0.25 M) of the aqueous species are1

Species

C6H12O6

H3PO4

C6H13O9P

H2O

ATP

ADP

-427

-1060

-1319 

-156

-2098

-1230

-1267

-1299

-2279

-286

-2996

-2006

The concentrations of species in erythrocytes are1

Species

C6H12O6

H3PO4

C6H13O9P

H2O

ATP

ADP

Concentration, M

0.005

0.001

0.000083

56

.00185

.00014

1Hammes GG, Thermodynamics and Kinetics for the Biological Sciences, Wiley-Interscience, 2000, chapter 3, Appendix 1.