H bonding i-i+3, i+1 in BS while i+2 in below LHH which virtually not allowed region

for most of amino acid except Gly that is why Gly is most conserved in type II B turns

                                                                Type II β turn

#Id: 1514

#Unit 2. Cellular Organization

Most microtubules in a cell consist of a simple tube, a singlet microtubule, built from 13 protofilaments. 

#Id: 1515

#Unit 2. Cellular Organization

 

#Id: 1516

#Unit 2. Cellular Organization

Triplet contains one complete 13-protofilament microtubule (A tubule) and two additional tubules (B & C tubule) consisting of 10 protofilaments each.

#Id: 1517

#Unit 2. Cellular Organization

#Id: 1518

#Unit 2. Cellular Organization

#Id: 1519

#Unit 2. Cellular Organization