Skip to Main Content

++

Section I: Proteins: Structure & Function

++
++
++

Select the one of the following statements that is NOT CORRECT.

++

The propensity of water molecules to form hydrogen bonds with one another is the primary factor responsible for all of the following properties of water EXCEPT:

++
++
++

A. Its atypically high boiling point.

++
++

B. Its high heat of vaporization.

++
++

C. Its high surface tension.

++
++

D. Its ability to dissolve hydrocarbons.

++
++

E. Its expansion upon freezing.

+
++

D. Hydrocarbons are water-insoluble.

++
++
++

Select the one of the following statements that is NOT CORRECT.

++
++
++

A. The side-chains of the amino acids cysteine and methionine absorb light at 280 nm.

++
++

B. Glycine is often present in regions where a polypeptide forms a sharp bend, reversing the direction of a polypeptide.

++
++

C. Polypeptides are named as derivatives of the C-terminal aminoacyl residue.

++
++

D. The C, N, O, and H atoms of a peptide bond are coplanar.

++
++

E. A linear pentapeptide contains four peptide bonds.

+
++

A. Phenylalanine, tyrosine, and tryptophan are the only protein amino acids that absorb light at 280 nm.

++
++
++

Select the one of the following statements that is NOT CORRECT.

++
++
++

A. Buffers of human tissue include bicarbonate, proteins, and orthophosphate.

++
++

B. A weak acid or a weak base exhibits its greatest buffering capacity when the pH is equal to its pKa plus or minus one pH unit.

++
++

C. The isoelectric pH (pI) of lysine can be calculated using the formula (pK2 + pK3)/2.

++
++

D. The mobility of a monofunctional weak acid in a direct current electrical field reaches its maximum when the pH of its surrounding environment is equal to its pKa.

++
++

E. For simplicity, the strengths of weak bases are generally expressed as the pKa of their conjugate acids.

+
++

D. Since at its pKa a weak acid bears no net charge, its mobility would be essentially zero in a buffer whose pH was equal to pKa.

++
++
++

Select the one of the following statements that is NOT CORRECT.

++
++
...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.