Here is a scheme describing the keto-enol tautomerization reaction. Design the catalytic site of an enzyme that would accelerate the rate of this reaction. The rate enhancement should be as great as possible. Draw the amino acids that would be involved in the reaction and the electron flow during each reaction step. Remember that the enzyme has to be regenerated at the end of catalysis.

A fuel with the composition of heptane (C7H16) is burned in an electricity-generating plant, with efficiency 36%. If the fuel has a specific energy of 26 MJ/kg, calculate CO2 emissions in units of kg/MJ electricity produced.

The minor condensation product formed by intramolecular aldol cyclization of octane-2,6-dione has a quartet absorption peak in the 1H NMR spectrum. What is its structure?

1. Glucokinase and hexokinase perform the same enzymatic function yet their role in carbohydrate metabolism / homeostasis is substantially different. a. Describe their cellular distribution / locations, functions, enzyme kenetics, and their regulation of each. b. Describe how each contributes to glucose homeostasis. c. Describe how insulin and glucagon may regulate these two enzymes. 2. The liver is centrally involved in the regulation of blood glucose levels. a. Describe what and how the liver contributes to glucose levels in both fed and fasted states b. Describe the molecular sources of substrates for glucose production. It is important to discuss the cellular source of these molecules as well as the physiological conditions in which they would be produced. c. Explain how and why blood glucose concentrations become dis-regulated during both fed and fasted states with type II diabetes.

A direct titration of .68311 grams sample of diprotic acid (H2X) requires 37.45 ml of 0.1372M NaOH solution. What is the experimental molecular weight of this organic acid: H2X+ 2NaOH -------->Na2X + 2H2O

1. How do polypeptides have the following types of effects: autocrine, paracrine, and endocrine

2. If you experimentally increase the concentration of Na+ outside a cell while maintaing other ion concentrations as they were, what would happen to the cell's membrane potential? Can you please exaplin why?

a - membrane potential would increase b - membrane potential would decrease c - membrane potential would be unaffected d - depends on thermodynamy potential

levels of protein structure

Find the ph for 0.350M of RbF

Calculate the pH of each of the following solutions. (Assume that all solutions are at 25°C.)

(a)    0.145 M acetic acid (HC₂H₃O₂, K_a = 1.8 ✕ 10⁻⁵)

(b)    0.145 M sodium acetate (NaC₂H₃O₂)

(d)    0.145 M HC₂H₃O₂ and 0.145 M NaC₂H₃O₂

_{hey so these are really stumping me, any heelp is appreciated, but it'd really be great if you could take a photo ofyour work done please so i can learn how it's done.. i keep getting it wrong}

10 mL of bleach with an unknown concentration is added to a 100mL volumetric flask. The solution is then finished with deionized water. 10 mL of this diluted bleach solution is then added to an erlenmeyer flask along with 1 scoop of KI, and 5 L of 2M HCl. This solution is then titrated with Na2S2O3 until it is a pale yellow color, then a starch indicator is added and titration is completed until the solution is clear. If 43 mL of Na2S2O3 was required, what is the percent of sodium hypochlorite in the bleach? How would it be calculated? A step by step answer would be very much appreciated.

NaOCL + 2HCl --> NaCl + H2O + Cl2

Cl2 + 2I- --> I2 +2Cl-

2S2O3^2- +I2 --> S4O6^2- +2I-

The boiling point of an aqueous solution is 101.42 °C. What is the freezing point?