This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET 2019, Subject name: Biochemistry
Type of collagen maximum in skin:- 
Select and explain. 
A. Type I, B. Type II, C. Type III, D. Type IV
A: Type I
Answer: A: Type I 
Explanation: Collagen - the most abundant protein in mammals contains 4-hydroxyproline and 5-hydroxylysine. Vitamin C plays the role of a coenzyme in hydroxylation of proline and lysine while protocollagen is conveed to collagen The hydroxylation reaction is catalysed by lysyl hydroxylase (for lysine) and prolyl hydroxylase (for proline) This reaction is dependent on vitamin C, molecular oxygen and a-ketoglutarate Type Distribution I Noncailaginous connective tissues, including bone, tendon, skin II Cailage, vitreous humor III Extensible connective tissues, including skin, lung, vascular system IV Basement membranes