90.In the synthesis of collagen, the hydroxylation of proline and lysine
occurs in which of the following?
a. Golgi apparatus
b. Secretory vesicles
c. Rough endoplasmic reticulum
d. Smooth endoplasmic reticulum
e. Lysosomes
91.Tropocollagen is not assembled in the cell because of which of the
following?
a. Action of lysyl oxidase in the Golgi apparatus
b. Acidity of clathrin-coated vesicles
c. Presence of nonhelical registration peptides at the ends of the triple helix
d. Presence of specific collagenases in the RER and Golgi apparatus
e. Presence of specific inhibitors of peptidase activity in the Golgi apparatus
92.The primary function of entactin (also known as nidogen) is to cross-
link which of the following?
a. Laminin to collagen
b. Cells to the basal lamina
c. Cells to the extracellular matrix
d. Collagen
e. Actin
93.A 14-year-old boy presents with thin, translucent skin, and a history of
easy bruising. Biochemical studies of the patient’s dermal fibroblasts cul-
tured from a skin biopsy show abnormal electrophoretic mobility and
abnormal secretion of type III procollagen. A mutation in the COL3A1
gene is identified by molecular testing. Which of the following symptoms
would be most expected in this patient?
a. Rupture of the intestinal or aortic walls
b. Hyperextensibility of the integument
c. Hypermobility of synovial joints
d. Increased degradation of proteoglycans in articular cartilages
e. Imperfections in dentin formation (dentinogenesis imperfecta)
Connective Tissue 173