A spirogram indicating changes in lung volume under different conditions of breathing.

TLS Online TPP Program

#Id: 7774

#Unit 2. Cellular Organization

Each nuclear pore is formed from an elaborate structure termed the nuclear pore complex (NPC), which is one of the largest discrete protein assemblages in the cell.

TLS Online TPP Program

#Id: 7775

#Unit 2. Cellular Organization

The total mass of the pore structure is 60,000– 80,000 kDa in vertebrates, which is about 16 times larger than a ribosome.

TLS Online TPP Program

#Id: 7776

#Unit 2. Cellular Organization

In one minute, each NPC is estimated to import 60,000 protein molecules into the nucleus, while exporting 50–250 mRNA molecules, 10–20 ribosomal subunits, & 1000 tRNAs out of the nucleus.

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#Unit 2. Cellular Organization

An NPC is made up of many copies of some 30 different proteins called nucleoporins.

TLS Online TPP Program

#Id: 7778

#Unit 2. Cellular Organization

Eight approximately 100-nm long filaments extend into the nucleoplasm with the distal ends of these filaments joined by a terminal ring, forming a structure called the nuclear basket.

TLS Online TPP Program

#Id: 7779

#Unit 2. Cellular Organization

The nucleoporins are of three types: 

a. Structural nucleoporins

b. Membrane nucleoporins

c. FG-nucleoporins