Trypsin and chymotrypsin are members of the family of serine proteases. They cleave peptide bonds at the C-terminal end of specific residues. Chymotrypsin recognizes aromatic residues, while trypsin recognizes lysine and arginine. The recognition of a particular side chain (side chain specificity) is fully determined by the structure and properties of the binding pocket. In the case of chymotyipsin the binding pocket is hydrophobic and is wide enough to accommodate an aromatic ring. Given what you know about the properties of Lys/Arg side chains, what can you say about the size/shape and possible interactions that would provide the substrate specificity in the case of trypsin? What amino acid residues from the trypsin molecule would you expect to find in the binding site?

Choose one of the transition or inner transition metals from the periodic table. (I choose Titanium) Using Chapter 23 of Chemistry, The Molecular Nature of Matter and Change, and Internet resources, discuss why your transition metal and their compounds display a variety of color. Be sure to include in your discussion, important oxidation states, the electron configuration and how the d-electrons are involved. How can you include the electromagnetic spectrum and the nature of light into your discussion? How is energy and wavelength related? Use your knowledge of the emission and absorption of light in your discussion. Remember to site your sources in APA style.

Are HCP metals typically more or less ductile than BCC metals? Why?

Does the spacing between the vibronic peaks in the fluorescence emission spectra have to be the same as those in absorption spectra? why?

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The equilibrium constant Kc for the Reaction:

H2(g) + CO2(g) <--> H2O(g) + CO(g) is 4.2 at 1650 C. Initially 0.87 mol H2 and 0.87 mol CO2 are injected into a 4.9 L flask. Calculate the concentraion of each species at equilibrium

Equilibrium concentration of H2: ____ M

Equilibrium concentraion of CO2: ___ M

Equilibrium concentraion of H2O: _____M

Equilibrium concentration of CO: ______M

A 350.0 −mL buffer solution is 0.170 M in HFand 0.170 M in NaF.

A) What mass of NaOH could this buffer neutralize before the pHrises above 4.00?

B) If the same volume of the buffer was 0.360 M in HF and 0.360 M in NaF, what mass of NaOH could be handled before the pH rises above 4.00?

Sodium fluoride is added to many municipal water supplies to reduce tooth decay. Calculate the pH of a 0.00307 M solution of NaF, given that the K_a of HF= 6.80 x 10^-4 at 25 degree celcius.

What is the effect of the following changes in the O2 affinity of hemoglobin? (a) A drop in the pH of blood plasma from 7.4 to 7.2. (b) A decrease in the partial pressure of CO2 in the lungs from 6 kPa (holding one’s breath) to 2 kPa (normal). (c) An increase in the BPG level from 5 mM (normal altitudes) to 8 mM (high altitudes). (d) An increase in CO from 1.0 part per million (ppm) in a normal indoor atmosphere to 30 ppm in a home that has a malfunctioning or leaking furnace.

An HNO3(aq) solution has a pH of 1.61. What is the molar concentration of the HNO3(aq) solution?

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Ethanol (C₂H₅OH) and gasoline (assumed to be all octane, C₈H₁₈) are both used as automobile fuel. If gasoline is selling for $3.19/gal, what would the price of ethanol have to be in order to provide the same amount of heat per dollar? The density and ΔH

of octane are 0.7025 g/mL and −249.9 kJ/mol and the density and ΔH

of ethanol are 0.7894 g/mL and −277.0 kJ/mol, respectively. Assume that the products of combustion are CO₂(g) and H₂O(l). (1 gal = 3.785 L)

When 0.653 L of Ar at 1.20 atm and 227°C is mixed with 0.278 L of O2 at 501 torr and 127°C in a 400. mL flask at 27°C, what is the pressure in the flask?

How many grams of each of the following per kilogram of water in your car radiator are needed to give equal protection against freezing down to -10.0 Degrees Celcius.

A: Methy Alchohol ( CH3OH) Boiling point = 64.6 C
B Ethyele glycol C2H4 )oh)2 Boiling point 197.2 C

C: In spite of the higer cost, what advantage does ethylene glycol possses over metyhly alchol as a winter antifreeze and/or suimmer coolant? Hint conisder the physical properties of each.

The B4O5(OH)4^2- ion, present in 5.0-Ml of a saturated Na2B4O5(OH)4 solution at a measured temperature, is titrated to the bromocresol endpoint with 3.25 mL of 0.291 M HCl.

a) How many moles of B4O5(OH)4^2- are present in the sample?

b) What is the molar concentration of B4O5(OH)4^2- in the sample?

c) Calculate the Ksp for Na2B4O5(OH)4 from this data.

d) What is the free energy change for the dissolution of Na2B4O5(OH)4 at this temperature?