0 of 1 questions completed
USMLE Step 1 Questions
You have already completed the quiz before. Hence you can not start it again.
Quiz is loading...
You must sign in or sign up to start the quiz.
You have to finish following quiz, to start this quiz:
Time has elapsed
You have reached 0 of 0 points, (0)
- Biochemistry 0%
Vitamin C deficiency results in scurvy. Vitamin C functions as a co-factor in which of the following steps of the collagen synthesis cascade?
Correct Answer: D. Hydroxylation of preprocollagen
The hydroxylation of specific proline and lysine residues on the preprocollagen strand requires vitamin C as a cofactor in the endoplasmic reticulum. There, the pro-alpha chain of collagen is glycosylated to form the triple-helixed procollagen. Procollagen is then sent to the Golgi apparatus and is exocytosed from the cell, where the ends are cleaved to form tropocollagen. These molecules are cross-linked to form collagen fibrils. Unlike most proteins, post-translational modification occurs in the RER rather than the Golgi apparatus.
Question 1 of 1
1. QuestionCategory: Biochemistry
Vitamin C deficiency results in scurvy. Vitamin C functions as a co-factor in which of the following steps of the collagen synthesis cascade?Correct