For a tetrapeptide, there are ____ unique sequences.

Although mutations can change the catalytic efficiency of an enzyme, we are certain that mutations will never alter the ________.

If the Keq of an enzyme-catalyzed reaction is highly favorable, then ________.

For the following amino acid (pK1 = 2.2 (carboxyl); pK2 = 8.6 (amino); pK3 = 10.5 (phenolic hydroxyl), the most abundant form at pH 9 is _______.  

In proteins, R-N–H···O=C-R bonds ________.

An enzyme ________________________________.

A channel protein

Countertransport

A governing system in which public decision making is delegated to representatives of the people chosen by popular vote in free, open, and periodic elections is a(n)

Surveys reflect substantial recent improvements in the overall state of political knowledge of American citizens.