Biochem HW 1 (Chapters 2-4)

Rank the following according to their strength as acids--rank from strongest (1)  to weakest (5).  

A: 4

B: 3

C: 5

D: 2
E: 1

Which of the following would NOT form a suitable buffer?

Hydrochloric acid/chloride

Under what conditions would a carboxyl group (COOH, pK 3.5) be mostly protonated?

pH < pK

Under what conditions would a carboxyl group (COOH, pK 3.5) be mostly deprotonated?

pH > pK

In aqueous solution, globules of up to several thousand amphiphilic molecules arranged with the hydrophilic groups on the surface and the hydrophobic groups buried in the center are called _____.

Micelles

What term is used to describe the exclusion of nonpolar substances from an aqueous solution?

Hydrophobic effect

Which of the following is an example of the hydrophobic effect?

all are examples of the hydrophobic effect.

A molecule that has both a polar and nonpolar region is called _____________.

Amphiphilic

If the pK value for acetic acid (CH₃COOH) is 4.76 at what pH would one observe equal amounts of CH₃COO^- and CH₃COOH?

4.76

T/F: The LOWER the pK value of an acid the STRONGER the acid.

True

A buffer contains 0.050M of lactic acid (pK= 3.86) and 0.010M of lactate per liter.  Use the Henderson-Hasselbalch equation to calculate the pH of the buffer.  Enter your answer to two decimal points.  

3.16