ch 5

What constitutes the bulk of animal hair?

Keratin filaments

What shape does a plot of the oxygen binding to myoglobin take compared to hemoglobin's shape?

Hyperbolic for myoglobin and sigmoidal for hemoglobin.

What is required for the production of hydroxyproline in collagen?

Ascorbic acid.

Which amino acids are most often incorporated into the growing collagen protein?

Glycine and Proline.

What do bone and tendons contain, while hair and nails contain what?

Bone and tendons contain Collagen; hair and nails contain Keratin.

Which amino acid is critical for crosslinking of collagen trimers?

Lysine.

What is the helical structure of collagen composed of?

Three left-handed helices wound around each other in a right-handed triple helix.

What is the most prevalent secondary structure observed in the proteins of intermediate filaments?

Alpha-helices.

What ion is central in the heme group of hemoglobin?

Fe(2+).

What occurs in hemoglobin upon oxygen binding?

The central cavity between the four subunits is decreased in size.

How does CO2 affect hemoglobin-oxygen binding?

CO2 is converted to bicarbonate and H+ which promotes the deoxy state.

In Hb S, which residue is replaced by which residue?

Glutamate is replaced by valine.

Why is the decreased affinity of fetal hemoglobin for BPG advantageous?

It reduces fetal hemoglobin's P50.

What explains the ability of carbon monoxide (CO) to bind to hemoglobin despite low concentrations?

CO binds to hemoglobin about 250 times more strongly than oxygen.

Which Nobel prize was awarded to John Kendrew and Max Perutz?

For their work on the structure of myoglobin and hemoglobin.