A child with a large head, multiple fractures, and blue sclerae (whites of the eyes) is evaluated for osteogenesis imperfecta. One study involves labeling of collagen chains in tissue culture to assess their mobility by gel electrophoresis. Amino acids labeled with radioactive carbon 14 are added to the culture dishes in order to label the collagen. Which of the following amino acids would not result in labeled collagen?
a. Serine
b. Glycine
c. Aspartate
d. Glutamate
e. Hydroxyproline