User:Marshallsumter: Difference between revisions
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=Introduction= | =Introduction= | ||
'''Nucleohyaloplasm''' is the [[cytosol]] within the [[nucleus]], without the [[microfilaments]] and the [[microtubules]]. This liquid part contains [[enzyme]]s and intermediate [[metabolite]]s. Many substances such as [[nucleotide]]s (necessary for purposes such as the [[DNA replication|replication of DNA]] and production of [[Messenger RNA|mRNA]]) and enzymes (which direct activities that take place in the nucleus) are dissolved in the nucleohyaloplasm. | |||
As a cytosol, it consists mostly of [[water]], dissolved ions, small molecules, and large water-soluble molecules (such as [[protein]]). It contains about 20% to 30% protein. It has a high concentration of K⁺ ions and a low concentration of Na⁺ ions. Normal human cytosolic [[pH]] ranges between 7.3 - 7.5, depending on the [[cell type]] involved.<ref name=Roos>{{cite journal |author=Roos A, Boron WF |title=Intracellular pH |journal=Physiol. Rev. |volume=61 |issue=2 |pages=296–434 |year=1981 |month=April |pmid=7012859 |url=http://physrev.physiology.org/cgi/pmidlookup?view=long&pmid=7012859}}</ref> | |||
=Small particles= | =Small particles= | ||
Revision as of 22:18, 20 February 2009
Introduction
Nucleohyaloplasm is the cytosol within the nucleus, without the microfilaments and the microtubules. This liquid part contains enzymes and intermediate metabolites. Many substances such as nucleotides (necessary for purposes such as the replication of DNA and production of mRNA) and enzymes (which direct activities that take place in the nucleus) are dissolved in the nucleohyaloplasm.
As a cytosol, it consists mostly of water, dissolved ions, small molecules, and large water-soluble molecules (such as protein). It contains about 20% to 30% protein. It has a high concentration of K⁺ ions and a low concentration of Na⁺ ions. Normal human cytosolic pH ranges between 7.3 - 7.5, depending on the cell type involved.[1]
Small particles
Small particles (< 30 kDa) are able to pass through the nuclear pore complex by passive diffusion. Larger particles are also able to pass through the large diameter of the pore but at almost negligible rates.[2] The average mass range for amino acids: 75.06714 - 204.22844 Da. The lateral speed of biological molecules in passive diffusion in water is on the order of 500 - 50 nm/sec. But in cytosol such as the nucleohyaloplasm: ~120-10 nm/sec due to crowding and collisions with large molecules.
Large particles
Structures
Human nucleohyaloplasm
- ↑ Roos A, Boron WF (1981). "Intracellular pH". Physiol. Rev. 61 (2): 296–434. PMID 7012859. Unknown parameter
|month=ignored (help) - ↑ Campbell, Neil A. (1987). Biology. p. 795. ISBN 0-8053-1840-2.