Get quote & make Payment
Chemical composition of chromatin, Biology
L COMPOSITION OF CHROMATIN
Chromatin threads composed of DNA (31 %), RNA (2-5%) and proteins (Histon-36%, Non histon 28%).
Histone and protamines are basic proteins. Histone protein composed of mainly Arginine, lysine and Histidine amino acids. Protamine has more arginine but lysine is absent. Histone occupy the major grooves of DNA at an angle of 30° to the helix, and it neutralise negative charges of intemucleotide phosphate in DNA. In procaryotes polyamines have simillar functions.
Histone protein discovered by
(Kossel also discovered purines and pyrimidines). On the basis of relative amount of arginine and lysine there are five types of histone proteins i.e. H
are arginine rich, H
A and H
B are slightly lysine rich and H
is highly lysine rich.
Non Histone protein of chromatin mainly composed of Tryptophan and Tyrosine amino acids. Non histone proteins occur more in euchromatin part where these activate segments of DNA for transcription.
worked out ultrastructure of chromatin. Under electron microscope chromatin appears beaded. Beads are called Nucleosome or Nu-body by
Wood cock and P. oudet
(1975) .Nucleosomes are 11 nm in diameter and 5.7 nm in height. Nucleosome model of chromatin proposed by
Each nucleosome composed of 140 pairs of nucleotides and 8 histone molecules.
Central core of nucleosome composed of histon and nucleotides of DNA form two coils (1% ) around this octamer of histone (two molecules each of H
). Nucleosomes are linked in a string by thin threads called linker. Linker composed of 60 pairs of nucleotides and one histone molecule (H
In chromatin, nucleosomes form coils called Solenoid of 30 nm in diameter. Each solenoid composed of six nucleosomes.
Posted Date: 10/5/2012 8:03:56 AM | Location : United States
Ask an Expert
Chemical composition of chromatin, Assignment Help, Ask Question on Chemical composition of chromatin, Get Answer, Expert's Help, Chemical composition of chromatin Discussions
Write discussion on Chemical composition of chromatin
Your posts are moderated
Write your message here..
Cell division., sir i''m not understanding cell division rightly. in ca...
sir i''m not understanding cell division rightly. in case of meiosis both paternal and maternal chromosome goes in two cell separately while in case of mitosis they go alongwit
Homologous proteins - amino acid sequence in fasta format, Please answer th...
Please answer the following question on Sequence Y: Protein databases 1. What sequence from which organism is this sequence most similar to? 2. Can you find any homo
Describe the types of drugs, Describe the types of Drugs • Induction a...
Describe the types of Drugs • Induction agent (thiopentone, fentanyl, ketamine, midazolam) • Suxamethonium (1-2 mg/kg) is the muscle relaxant of choice. Rapid sequence ind
What are extraembryonic membranes, What are extraembryonic membranes? E...
What are extraembryonic membranes? Extraembryonic membranes are membranous structures that appear in parallel with the embryo and play significant roles in the embryonic develo
Hybridisation, what is sunandini
what is sunandini
What are the corals, Q What are the corals? Corals are characterized by...
Q What are the corals? Corals are characterized by their polypoid shape, slow growth and sessility and secretion of a solid skeleton made of calcium carbonate. Numerous coral i
Hindbrain - cerebellum, HIND BRAIN - 1 . CEREBELLUM - Li...
HIND BRAIN - 1 . CEREBELLUM - Little part, lies below the posterior part of cerebrum & above the medulla oblongeta. It conists of median lobe vermis & 2 lat
Explain the the system of the nomenclature, Explain the The system of the n...
Explain the The system of the nomenclature The system of the nomenclature and the classification of enzymes is based exclusively on the reaction that is catalyzed and does not
What type of compound is major metabolic waste of porifera, What type of co...
What type of compound is the major metabolic waste of Porifera? Why is it important for the organism to get rid of this compound?
Glucocorticoid response element, GRE stands for the Glucocorticoid Respons...
GRE stands for the Glucocorticoid Response Element: The binding site in a promoter to which the activated glucocorticoid receptor can be bind. The glucocorticoid receptor is signi
Accounting Assignment Help
Economics Assignment Help
Finance Assignment Help
Statistics Assignment Help
Physics Assignment Help
Chemistry Assignment Help
Math Assignment Help
Biology Assignment Help
English Assignment Help
Management Assignment Help
Engineering Assignment Help
Programming Assignment Help
Computer Science Assignment Help
IT Courses and Help
Why Us ?
~24x7 hrs Support
~Quality of Work
~Time on Delivery
~Privacy of Work
Human Resource Management
Literature Review Writing Help
Follow Us |
T & C
Copyright by ExpertsMind IT Educational Pvt. Ltd.