Nuclear membrane - structure of nucleus, Biology

KARYOTHECA OR NUCLEAR MEMBRANE

  1. It is also called Nucleolemma, term given by Erclab & Hertwig.
  2. Karyotheca composed of two unit membranes separated by a 150-300 A° wide perinuclear space. Outer membrame may have 80s ribosomes.E.R. is connected to outer nuclear membrane at several places.
  3. Just beneath inner nuclear membrane, there is a fibrous layer called fibrous lamina. It provides strength to nuclear membrane and also provides attachment site to peripheral heterochromatin.
  4. Nuclear membrane is perforated by nuclear pores of 400 - 1000 Aº diameter with space 1500 Aº . In the oocyte of frog (Xenopus laevis) 30 million nuclear pores are present. Nuclear pores are covered by an octagonal structure composed of eight granular subunits called Annulus or Bleb. Anulus and nuclear pore collectively called pore complex.
  5. These pores regulates transport bet. nucleoplasm and cytoplasm, Small ions like K+, Na+ and Cl- move through nuclear membrane while t-RNA ,r-RNA and m- RNA pass through nuclear pores. Protein nucleoplasmin which occur in pore complex regulates the nucleo cytoplasmic traffic .

357_nucleus.png

Posted Date: 10/5/2012 7:57:48 AM | Location : United States







Related Discussions:- Nuclear membrane - structure of nucleus, Assignment Help, Ask Question on Nuclear membrane - structure of nucleus, Get Answer, Expert's Help, Nuclear membrane - structure of nucleus Discussions

Write discussion on Nuclear membrane - structure of nucleus
Your posts are moderated
Related Questions
What are Tannins? Long known for their inhibitory effects on iron absorption, recent research indicates that tannins do have beneficial effects. Tannins are compounds of high m

Coding sequence is the portion of the gene or the mRNA which actually codes for a protein. Introns are not coding for the sequences; nor are the 5' or 3' untranslated regions (or

What is the Vacuum Puff Drying? The vacuum puff process has been developed for drying liquids under vacuum. The development of processes for drying liquids under vacuum came fr

How is L. monoctogenes infection transmitted? Listriosis caused by Listeria monocytogenes infection. Transmitted by animal excretions (faecal matter) and secretions, infecte

Q. Explain about Food Exchange System? In a diabetic's day to day diet, the calorie intake and the quantity of food consumed should not have wide fluctuations. Also the diet sh

In hormonal terms why does menses occur? Menses is the endometrial monthly desquamation that happens as the estrogen and progesterone levels fall after the regression of the co

The oxidation of sugar in the cell of higher organisms takes place in the where

PECTIN It consists of methylated galacturonic acid, galactose & arabinose. It is also called plant cement becuase it binds layers of cell wall. It is a structural poly

Solutes and ions tie up water in solution. Solutes lower aw and this reduction in aw depends on the total concentration of dissolved molecules and ions. Since these bind to water m

Disease and Pathogenesis Disease management is a complex and challenging undertaking. Not only are new pathogens and treatments constantly being discovered by effective