Principles of Biochemistry January 15, 2010 Titration curve. The acid and Conjugate base species in this mixture: When the concentration of the acid and CB and Salt are equal, the pH=pka. The slope of the titration curve is not as great as it is when they are almost converted. The mixture of acid and conjugate base is Buffering causing it to resist change in pH. If you didn’t have a buffer and you had an acid, you get very pronounced changes. When you start running out of salt, the next couple drops of titration cause a dramatic change. The plus or minus 1 rule defines the area of the pH scale in the titration curve where the buffer system effectively resists change in pH as a result of the addition of acid. Amino Acids Have an alpha carbon with a carboxyl group, hydrogen, and a side-chain. Tetrahedral structure is present.