Metabolic Bone Diseases
The disease that results in deficient hydroxyla¬tion of the pro-alpha chains of collagen is known as
a. Proline hydroxylase and lysine hydroxylase are responsible for hydroxylation of the pro-alpha chains of collagen in the endoplasmic reticulum.
b. These enzymes require ferrous iron, molecular oxygen, and ascorbic acid (vitamin C. as cofactors. Scurvy, or vitamin C deficiency, impairs the function of these enzymes.
c. Patients with Ehlers-Danlos syndrome have defects in the cross-linking of mature collagen fibers. Marfan's syndrome has many variants, most of which exhibit extra amino acids on the procollagen chains.
d. Lathyrism is a disease of animals caused by eating the seeds of sweet peas, which contain a substance that inhibits cross-linking of mature collagen fibers