When explaining why some children have albinism, the science teacher explains that which enzyme is needed for synthesis of melanin?

Question

A) Laminim
B) Tyrosinase
C) Bradykinin
D) Pheomalanin

Answer 1

Ans: B
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Although there are more than 10 different types of albinism, the most common type is recessively inherited oculocutaneous albinism, in which there is a normal number of melanocytes, but they lack tyrosinase, the enzyme needed for synthesis of melanin. The lamina lucida consists of fine anchoring filaments and a cell adhesion glycoprotein, called laminin, which plays a role in the organization of the macromolecules in the basement membrane zone and promotes attachment of cells to the extracellular matrix. Many chemicals have been found to produce the itch sensation, including histamine, serotonin, and cytokines. Substances such as bradykinin and bile salts act locally to stimulate the itch sensation. Localized concentrations of eumelanin are also responsible for the formation of freckles and moles. Pheomelanin, a reddish yellow pigment, is particularly concentrated in the lips, nipples, glans penis, and vagina.