BIOLOGY
PROTEINS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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A 1, 2 and 3
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B 1 and 2 only
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C 1 and 3 only
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D 2 and 3 only
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Detailed explanation-1: -Collagen is almost unique among proteins in its use of triple-helical secondary structure. The triple-helix is composed of three polypeptide chains, each with the repeating triplet Gly-X-Y, where X and Y are frequently (∼22% occurrence of each in type I collagen) proline and 4-hydroxyproline, respectively.
Detailed explanation-2: -The repeating amino acid sequence present in collagen typically represents a left-handed helical conformation of the collagen polypeptide chains. This helical conformation represents the secondary structure of collagen.
Detailed explanation-3: -Collagens are characterized by their unique tertiary structure, called the collagen triple helix, and by their existence in extracellular matrices (ECMs).
Detailed explanation-4: -The defining feature of collagen is an elegant structural motif in which three parallel polypeptide strands in a left-handed, polyproline II-type (PPII) helical conformation coil about each other with a one-residue stagger to form a right-handed triple helix (Figure 1).