Search found 2 matches

by jsmcd1
Tue Sep 09, 2008 3:00 am
Forum: Molecular Biology
Topic: biochemistry for dummies (me, that is...)
Replies: 8
Views: 15265

Re: biochemistry for dummies (me, that is...)

Last one for a bit I hope. I need to find the two main ionization states of histidine at pH of 5.0, and the percent of ea present. My approach is this: pKa of COOH is 1.82, pKa of H3N+ is 9.17. Ph= pKa + log [coo-]/[cooh], 5.0 = 1.82 log [A-]/[HA], 3.18 = log [A-]/[HA], 3.18 antilog = [A-]/[HA] = 15...
by jsmcd1
Sat Sep 06, 2008 9:32 pm
Forum: Molecular Biology
Topic: biochemistry for dummies (me, that is...)
Replies: 8
Views: 15265

Re: biochemistry for dummies (me, that is...)

Greetings all. After a 20 yr hiatus for general chemistry I thought it would be a good idea to jump right into Biochemistry.... I need help with the following question. "the pKa of the acid group in aspirin is 3.5. What percent of the aspirin is in the neutral form in the stomach (pH 2.0)? What...