Consider 1000 bp DNA.

500 bp is sequence a, present in a single copy.

500 bp is sequence b (100 bp) repeated 5 times:

TLS Online TPP Program

#Id: 8147

#Unit 2. Cellular Organization

A clathrin molecule,

called a triskelion, is composed of : 

Three heavy chains

Three light chains

TLS Online TPP Program

#Id: 8148

#Unit 2. Cellular Organization

Depolymerization of the clathrin coat into triskelions  by Cytosolic Hsp70

TLS Online TPP Program

#Id: 8149

#Unit 2. Cellular Organization

ARF and Sar1 similar to Ras

TLS Online TPP Program

#Id: 8150

#Unit 2. Cellular Organization

Sar1 is the only GTPase switch protein activated at the ER membrane

TLS Online TPP Program

#Id: 8151

#Unit 2. Cellular Organization

Sec12

acts as a GEF factor for Sar1

TLS Online TPP Program

#Id: 8152

#Unit 2. Cellular Organization

After the vesicle coat is complete, the Sec23 coat subunit promotes GTP hydrolysis causes disassembly of the coat.