Practice Test 1 key

Practice Test 1 key - spontaneous. Therefore, G for the...

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BCH4053 PRACTICE MINI-TEST 1 Sept. 16, 2005 Multiple Choice – Circle the correct answer (1) What is the pH of an aqueous solution of 5.0 x 10 -7 M HCl A) 6.90 B) 7.00 C) 6.30 A)6.22 D) 5.10 (2) Which of the following biomolecules is NOT a metabolite: A) pyruvate 2. ribonuclease A C) glucose D) ATP E) citrate Short Answer – Show your work for partial credit (3) Vitamin C (ascorbic acid) is a diprotic acid, with the following pK values: pK 1 = 4.1; pK 2 = 11.8. If Vitamin C were excreted in the urine of a patient, and the urine had a pH of 4.5, what fraction of the vitamin would carry a negative charge? 72% or 0.72 would carry a negative charge
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(4) Underline the following peptides that are negatively charged at pH 7.0. Circle each aromatic amino acid and put an X through each amino acid that contains a sulfur atom. Gln-Phe-Tyr-Ala His-Arg-Gly-Trp Ile-Lys-Met-Asp Cys-Pro-Glu-Asn Aromatics include Phe, Tyr and Trp (6) In the hydrophobic effect, the association of non-polar groups in water is
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Unformatted text preview: spontaneous. Therefore, G for the process is __ negative _____ (negative or positive?). The association occurs primarily because the water is more disordered in the state where the non-polar groups are associated. Therefore, the overall S for the process is ____ positive _______ (negative or positive?). Lowering the temperature in this case would _____ decrease ______ (increase or decrease?) the strength of the hydrophobic effect (Hint: How would G be affected). X X (5) Amino acid analysis of a six residue peptide gave the following: Tyr Gly Lys Trp Asp Met Given the following information, what is the sequence of this oligopeptide (a) trypsin treatment had no effect (b) brief digestion with chymotrypsin yielded a dipeptide and a tripeptide (c) cyanogen bromide treatment yielded two tripeptides, one of which contained G, W and K. Tyr-Asp-Met-Trp-Gly-Lys...
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Practice Test 1 key - spontaneous. Therefore, G for the...

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