Reading quiz 1

Your book states that "The polypeptide backbone is rich in hydrogen-bonding potential." Which of the following are capable of hydrogen bonding? Choose all that apply.

Amino group Carbonyl group

Look at Figure 4.11 in your textbook. Is the following statement true or false: an alpha helix has a pore (empty space) in the middle.

False

Can sodium ions move through the potassium ion channel? Choose the best answer.

No, they cannot form favorable interactions with the selectivity filter or the pore.

Choose all of the correct statements about protein structure. Hint: For each level of structure, only one statement is correct.

Primary structure is due to covalent bonding between amino acids. Secondary structure is due to hydrogen bonding between amino acids. Tertiary and quaternary structure is primarily due to the hydrophobic effect, hydrogen bonding, ion-ion interactions, and van der Waals interactions.

Which of the following statements correctly describes the bonds and the distribution of charge in a water molecule?

The bonds between O and H are covalent bonds, and the electrons spend more time near O than H.

Look at Figure 12.22. What must happen to the potassium ion as it moves from the blue area of the pore to the yellow area.

The ion-dipole interaction between potassium and water must be broken.

Look at Figure 4.6 in your textbook. Which of the following is true about the peptide bond. Choose all true statements.

The plane of the peptide bond contains the following atoms: the alpha-carbon atom and CO groups of the first amino acid, the NH group and alpha-carbon of the second amino acid. The peptide bond is uncharged.

Salt dissolves well in water as water molecules

surround the ions because of their charge interactions with water but do not form hydrogen bonds.