The Medical College - Page 75

by the information given, and D is neither sup-

ported nor contradicted.

216.

Glycine has no chiral center, but other amino

acids in higher animals are ordinarily of the L-

series.

217.

Carbohydrate monosaccharides found in

higher animals are generally of the D-series.

218.

Epimers differ in configuration at only one

carbon. Enantiomers are nonsuperimposable mir-

ror images. Diastereomers are nonsuperimposable

nonmirror images.

219.

The number of kcal/g for the classes of food

material are: carbohydrates, 4; proteins, 4; and

fats, 9. The nucleic acids are not considered as a

class of food.

214.

Examination of the data shows that all three

proteins were absorbed at the same rate (2 min-

utes) by the visceral endoderm; the visceral endo-

derm appeared to block the transport of protein Y,

whereas protein X appeared to be transported

through it. The statement that the visceral base-

ment membrane blocked the transport of protein

X is not supported by the data because it is found

at the next level, namely, the vitelline endothe-

lium. The vitelline endothelium does, however,

block protein X from entering the fetal blood.

215.

The fiber components of connective tissue

add strength and support. They are collagenous,

elastic, and reticular in nature; collagen fibers are

the most numerous fiber type. The graphs show

that labeled proline starts to appear in the colla-

gen in under 2 hours, so B was supported by the

evidence. Statements A and C were contradicted

Citing this material