Fill in the blanks 1. the atoms of the groups and the hydrogen atoms attached to the atoms form .
(answer choices; nitrogen, carbon, a-helices or b-pleated sheets, carbonyl, globular of firbrous structures, oxygen, amino, random coil, thiol)
2. In the a helix, hydrogen bonds form between the oxygen atom and the hydrogen atom of a peptide bond in . In the B-pleasted sheet, hydrogen bonds form between the oxygen atom and the hydrogen atom of a peptide bond in .
(answer choices; parallell sections of a long polypeptide chain, the next amino acid unit, carboxyl, the next turn of the helical chain, thiol, amino, carbonyl)

1. oxygen; carbonyl; nitrogen; α-helices or β-pleated sheets

2. carbonyl; amino; the next turn of the helical chain; carbonyl; amino; parallel sections of a long polypeptide chain.

Explanation:

The secondary structure of proteins is of two major conformations, the α helix and β conformations which are very stable.

1. The oxygen atoms of the carbonyl groups and the hydrogen atoms attached to the nitrogen atoms form α-helices or β-pleated sheets.

2. In the α-helix, hydrogen bonds form between the carbonyl oxygen atom and the amino hydrogen atom of a peptide bond in the next turn of the helical chain. In the β-pleated sheet, hydrogen bonds form between the carbonyl oxygen atom and the amino hydrogen atom of a peptide bond in parallel sections of a long polypeptide chain.

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.