6 5 Consider the weak acid H₂A and its conjugate base HA-. Which diagram below represents a buffer solution? Explain your 362 answer. A = H₁₂A Exploring General, Organic, & Biochemistry in the Laboratory B = HA-

80mL of a 0.3M solution of hexapeptide Leu-His-Cys-Glu-Asn-Arg is adjusted to pH=pI. The solution is then titrated with 0.2M HCL to a final pH of 2.1. Sketch the titration curve, labelling the pH and volume axes. Indicate the volume of HCL needed to reach relevant pKa value and equivalence point(s)z Relevant pKa values are: 2.1, 4.3, 6.0, 8.3, 9.8, and 12.5.

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Refer to the following titration curve below: 13 12 11 10 9 7 6 5 4 3 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Volume of Titrant / mL - Unknown Acid 0.10 mol/L - titrant = NaOH 0.1 mol/L At ph 10.0, which form of histidine is most abundant? His2+ His- His° His+

Hi! For the first part, you need to put appropriate reagent (found below the diagram) to the space provided that will yield the given results. For the second part, you need to determine the reagent/s needed to confirm the identity of the cation from question 1. There can be more than one answer.    Thank you!

A) Identify the structures that would be found in proteins B) identify the structures that polymerize via condensation reactions

The octapeptide gly-cys-met-asn-lys-ala-tyr-gly was hydrolyzed consecutively by CNBr and then trypsin (3 fragments total). The mixture of fragments was buffered at a pH 8.5 and then chromatographed on an anion-exchanger (positive resin) with the same buffer. Draw sequence (abbreviated form) of all fragments at that pH (show charges) and predict elution order.

A colleague has successfully purified the enzyme sphingomyelinase from bovine brain. She provides you with the following incomplete purification table: Specific Activity (nmol/min) (nmol/min/mg) (%) Purification Factor (-fold) Total Total Purification Step Activity Yield Protein (mg) 100 1 Whole homogenate 40-60% (NH4);SO4 CM-sepharose ConA-sepharose Gel filtration Isoelectric focusing 88,625 5,685 925 544 51,700 32,067 29,500 31,680 1,855 420 5 0.03 (A) (B) (C) Per your colleague's request, you agree to calculate: (A) the final specific activity, (B) the final % yield, and (C) the final fold-purification. - x x x x *xx x x

Pyridine (right)is an essential portionof many biologically active compounds,such as nicotine and vitamin B₆. Like ammo-nia, it has a nitrogen with a lone pair, which makes it act as a weak base. Because it ismiscible in a wide range of solvents, fromwater to benzene, pyridine is one of the most important basesand solvents in organic syntheses. Account for its solubility behavior in terms of intermolecular forces

Quantitative Estimation of Amino Acids by Ninhydrin http://vlab.amrita.edu/?sub=3&brch=63&sim=156&cnt=2 can u help me with question 2 of the assignment questions  Based on the experimental data provided, estimate the amount of amino acid in the given unknown solution by Ninhydrin method. SI No. Volume of standard amino acid solution (ml) Amount of amino acid (µg) OD at 570nm 1 Blank   0 2 0.2   0.12 3 0.4   0.25 4 0.6   0.45 5 0.8   0.55 6 1.0 100 0.68 7 Unknown (0.5ml)   0.41