|
Search over 100 encyclopedias and dictionaries: |
Research categories | Follow us on Twitter |
Research categories
View all topics in the newsView all reference sources at Encyclopedia.com |
|||
chromatin
chromatin The substance of which eukaryotic chromosomes are composed. It consists of proteins (principally histones), DNA, and small amounts of RNA. The DNA molecule is wrapped around the histones to form a series of linked globular nucleosomes, resembling beads on a string. This is itself coiled to form a highly condensed solenoid arrangement, constituting a form of chromatin called heterochromatin, which stains densely with basic stains. The genes in the solenoid can only be transcribed if the solenoid unfolds to some extent, forming an expanded chromatin (euchromatin), which is lighter staining. The degree of condensation in any particular region is regulated by reversible acetylation of the histones: the greater the degree of acetylation, the less condensed the chromatin, and hence the greater the availability of genes for transcription.
|
|
|
Cite this article
"chromatin." A Dictionary of Biology. 2004. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "chromatin." A Dictionary of Biology. 2004. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O6-chromatin.html "chromatin." A Dictionary of Biology. 2004. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-chromatin.html |
|
chromatin
chromatin The substance of chromosomes, which includes DNA, chromosomal proteins, and chromosomal RNA. Chromatin stains strongly with basic dyes. It is thought that the chromatin is most deeply stained when it is most condensed and inactive.
|
|
|
Cite this article
MICHAEL ALLABY. "chromatin." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "chromatin." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O7-chromatin.html MICHAEL ALLABY. "chromatin." A Dictionary of Plant Sciences. 1998. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-chromatin.html |
|
chromatin
chro·ma·tin / ˈkrōmətən/ • n. Biol. the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA. |
|
|
Cite this article
"chromatin." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "chromatin." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O999-chromatin.html "chromatin." The Oxford Pocket Dictionary of Current English. 2009. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-chromatin.html |
|
chromatin
chromatin (kroh-mă-tin) n. the material of a cell nucleus that stains with basic dyes and consists of DNA and protein: the substance of which the chromosomes are made.
|
|
|
Cite this article
"chromatin." A Dictionary of Nursing. 2008. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "chromatin." A Dictionary of Nursing. 2008. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O62-chromatin.html "chromatin." A Dictionary of Nursing. 2008. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-chromatin.html |
|
chromatin
chromatin The substance of chromosomes, which includes DNA, chromosomal proteins, and chromosomal RNA. Chromatin stains strongly with basic dyes.
|
|
|
Cite this article
MICHAEL ALLABY. "chromatin." A Dictionary of Zoology. 1999. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "chromatin." A Dictionary of Zoology. 1999. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1O8-chromatin.html MICHAEL ALLABY. "chromatin." A Dictionary of Zoology. 1999. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-chromatin.html |
|
chromatin
chromatin see chromosome . |
|
|
Cite this article
"chromatin." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 29 May. 2012 <http://www.encyclopedia.com>. "chromatin." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 29, 2012). http://www.encyclopedia.com/doc/1E1-X-chromatin.html "chromatin." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 29, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-X-chromatin.html |
|