Nucleoid Region

Information about Nucleoid Region

Prokaryote cell showing the nucleoid.

In prokaryotes, the nucleoid (meaning nucleus-like and also known as the nuclear region, nuclear body or chromatin body) is an irregularly shaped region within the cell where the genetic material is localized. The nucleic acid is a circular, double-stranded piece of DNA and multiple copies may exist. This method of genetic storage can be contrasted against that of the eukaryotes, where DNA is packed into chromatins and sequestered within a membrane-bound organelle called the nucleus. The nucleoid can be clearly visualised on an electron micrograph at high magnification, where although its appearance may differ, it is clearly visible against the cytosol. Sometimes even strands of what is thought to be DNA are visible. By staining with the Feulgen stain, which specifically stains DNA, the nucleoid can also be seen under a light microscope.

Composition

Experimental evidence suggests that the nucleoid is largely composed of DNA, about 60%, with a small amount of RNA and protein. The latter two constituents are likely to be mainly messenger RNA and the transcription factor proteins found regulating the bacterial genome. Proteins helping to maintain the supercoiled structure of the nucleic acid are known as nucleoid proteins and are distinct from the functionally similar histones present in eukaryotic nuclei.

References

Prescott, L. (1993). Microbiology, Wm. C. Brown Publishers, ISBN 0-697-01372-3

• • [ e] Organelles of the cell
Acrosome - Cell wall - Cell membrane - Chloroplast - Cilium/Flagellum - Centrosome - Cytoplasm - Endoplasmic reticulum - Endosome - Golgi apparatus - Lysosome - Melanosome - Mitochondrion - Myofibril - Nucleus - Nucleolus - Parenthesome - Peroxisome - Plastid - Ribosome - Vacuole - Vesicle

Prokaryotes (IPA: /prəʊˈkæriəʊtiz/) are a group of organisms that lack a cell nucleus (= karyon), or any other membrane-bound organelles.
..... Click the link for more information.

Editing of this page by unregistered or newly registered users is currently disabled due to vandalism.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.

Genetic material is used to store the genetic information of an organic life form. For all currently known living organisms, the genetic material is almost exclusively Deoxyribonucleic Acid DNA. Some viruses use Ribonucleic Acid RNA as their genetic material.
..... Click the link for more information.

Chromatin is the complex of DNA and protein that makes up chromosomes. It is found inside the nuclei of eukaryotic cells, and within the nucleoid in prokaryotes.^[1] The nucleic acids are in the form of double-stranded DNA (a double helix).
..... Click the link for more information.

nucleus (3) ribosome (4) vesicle (5) rough endoplasmic reticulum (ER) (6) Golgi apparatus (7) Cytoskeleton (8) smooth ER (9) mitochondria (10) vacuole (11) cytoplasm (12) lysosome (13) centrioles]]

In cell biology, the nucleus (pl.
..... Click the link for more information.

micrograph, microphotograph or photomicrograph is a photograph or similar image taken through a microscope or similar device to show a magnified image of an item. Canadian inventor Reginald Aubrey Fessenden is credited with inventing photomicrography.
..... Click the link for more information.

The cytosol (cf. cytoplasm, which also includes the organelles) is the internal fluid of the cell, and a portion of cell metabolism occurs here. Proteins within the cytosol play an important role in signal transduction pathways and glycolysis.
..... Click the link for more information.

Feulgen stain is a staining technique discovered by Robert Feulgen and used in histology to identify chromosomal material or DNA in cell specimens. It depends on acid hydrolysis of DNA, therefore fixating agents using strong acids should be avoided.
..... Click the link for more information.

Left: An RNA strand, with its nitrogenous bases. Right: Double-stranded DNA.]] Ribonucleic acid or RNA is a nucleic acid polymer consisting of nucleotide monomers, which plays several important roles in the processes of translating genetic information from
..... Click the link for more information.

Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues.
..... Click the link for more information.

Messenger Ribonucleic Acid (mRNA) is a molecule of RNA encoding a chemical "blueprint" for a protein product. mRNA is transcribed from a DNA template, and carries coding information to the sites of protein synthesis: the ribosomes.
..... Click the link for more information.

This article or section may be confusing or unclear for some readers.
Please [improve the article] or discuss this issue on the talk page. This article has been tagged since December 2006.
..... Click the link for more information.

histones are the chief protein components of chromatin. They act as spools around which DNA winds, and they play a role in gene regulation.

Classes

Six major histone classes are known:

* H1 (sometimes called the linker histone; also related to Histone H5.

..... Click the link for more information.

A plasmid is a DNA molecule separate from the chromosomal DNA and capable of autonomous replication. It is typically circular and double-stranded. It usually occurs in bacteria, sometimes in eukaryotic organisms (e.g.
..... Click the link for more information.

In cell biology, an organelle is a specialized subunit within a cell, having a specific function, and separately enclosed within its own lipid membrane.

The name organelle
..... Click the link for more information.

In spermatozoa of many animals, the Acrosome is an organelle that develops over the anterior half of the spermatozoon's head. It is a cap-like structure derived from the Golgi apparatus. Acrosome formation is completed during testicular maturation.
..... Click the link for more information.

cell wall is a fairly rigid layer surrounding a cell, located external to the cell membrane, which provides the cell with structural support, protection, and acts as a filtering mechanism. The cell wall also prevents over-expansion when water enters the cell.
..... Click the link for more information.

Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide to produce sugars, the raw material for energy and biomass production in all green plants
..... Click the link for more information.

cilium (plural cilia) is an organelle found in eukaryotic cells. Cilia are thin, tail-like projections extending approximately 5–10 micrometers outwards from the cell body.
..... Click the link for more information.

For the insect anatomical structure, see .

A flagellum (plural: flagella) is a long, slender projection from the cell body, composed of microtubules and surrounded by the plasma membrane.
..... Click the link for more information.

The centrosome is the main microtubule organizing center (MTOC) of the cell as well as a regulator of cell-cycle progression. It was discovered in 1888 by Theodor Boveri and was described as the 'special organ of cell division.
..... Click the link for more information.

Cytoplasm is a gelatinous, semi-transparent fluid that fills most cells. Eukaryotic cells contain a nucleus that is kept separate from the cytoplasm by a double membrane layer. The cytoplasm has three major elements; the cytosol, organelles and inclusions.
..... Click the link for more information.

In biology, an endosome is a membrane-bound compartment inside cells, roughly 300-400 nm in diameter when fully mature^[1]. Many endocytotic vesicles derived from the plasma membrane are transported to an endosome and fuse with it.
..... Click the link for more information.

This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.

Herod_Archelaus

iPedia Free Information Center