Mid 1 Fall 2009

Mid 1 Fall 2009 - 1 of 1 BIS 102 Fall, 2009 K. Hilt Name_...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
1 of 1 BIS 102 Name__________________________________________________ Fall, 2009 Last First K. Hilt First Midterm Score (100): ___________ Equations: pH = pK a + log {[b]/[a]} K a = x 2 /(y-x) K b = x 2 / (y-x) pH = (pK a 1 + pK a 2 )/2 (K a )(K b ) = 1 x 10 -14 Amino acid pK a ’s: -carboxyl group (2.1), -amino group (9.6) side chains: D (3.9) E (4.2) H (6.0) C (8.3) Y (10.1) K (10.5) R (12.5) Oligopeptide pK a ’s: C-terminal carboxyl group (3.6), N-terminal amino group (7.4) 1. (10 pts.) In the space below, calculate the pI of glycine and draw the complete structure of the form of glycine that would predominate at this pH. 2. (20 pts.) How many moles of HCl are required to lower the pH of 4.00 liters of 25 mM glycine, pH 9.50, to a final pH of 2.40? Assume that the addition of HCl does not change the volume of the solution. Put your answer on this line: _____________ mols of HCl. To receive credit, show all of your work on the back of this page. 3.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.
Ask a homework question - tutors are online