On amino acid titration curves, using pH, pKa, etc, how do we know which hydrogens to remove at which states? I know it has to do with the acidity, and that at low pH the structure gets protonated and whatnot, but how do I know the order in which to protonate/deprotonate?

A sample containing the amino acid alanine plus inert matter is analyzed by the Kjeldahl methold. A 2.00-g sample is digested, the NH₃ is distilled and collected in 50.0 mL of 0.150 M H₂SO₄, and a volume of 9.0 mL of 0.100 M NaOH is required for back-titration. Calculate the percent alanine in the sample.

Which one of these is not an allosteric effector of hemoglobin binding to O2?

a.CO which binds in the same spot as O2

b.2,3-BPG which binds in the middle of the tetramer

c.CO2 which binds at the N-terminus of the subunits

d.H+ which binds to the amino acid side chains disrupting IM forces

Q. A certain amino acid has the following elemental composition: C, H, O, N. In a combustion analysis, 3.263g of it was combusted to produce 5.910g of CO2 and 2.835g of H2O. Separate analysis determined that it is 19.17% N, and its molar mass is 150g/mol. Determine its empirical and molecular formula.

How does an increase or decrease in pH affect the composition and charge of a functional group(s)?

What is the orientation of a water molecule around a negatively charged ion? Positively charged ion?

Would nonpolar side chains make an amino acid hydrophilic or hydrophobic? What about polar side chains?

In emergency care unite, TPN prescribed to a patient weight 88kg. He needs the following macronutrient: 500 cc of 10% lipid fat – 48 g of protein using 10% amino acid solution and D70.

A) Calculate the total osmolality of the TPN.

B) How many grams of fat will be used?

It is possible to make some predictions about protein secondary structure based on the primary sequence. Consider the following amino acid sequence:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Ile-Ala-His-Thr-Tyr-Gly-Pro-Phe-Glu-Ala-Ala-Met-Cys-Lys-Trp-Glu-Ala-Gln-Pro-Asp-Gly-Met-Glu-Cys-Ala-Phe-His-Arg

A) Where might Beta-Turns occur?

B) Where might intrachain disulfide cross-linkages be formed?

C) Assuming that this sequence is part of a larger globular protein, what is the probable location (exterior or interior of the protein) of the amino acid residues:

Asp Ile Thr Ala Gln Lys

Explain your reasoning.