Chopper (electronics)

2014-01-09T00:27:20Z

86.160.126.67: the plural of "basis" is "bases", see Wiktionary

In [[functional analysis]] and related areas of [[mathematics]] an '''absorbing set''' in a [[vector space]] is a [[Set (mathematics)|set]] ''S'' which can be ''inflated'' to include any element of the vector space. Alternative terms are '''[[radial set|radial]]''' or '''absorbent set'''.

==Definition==

Given a vector space ''X'' over the [[field (mathematics)|field]] '''F''' of [[Real number|real]] or [[Complex number|complex]] numbers, a set ''S'' is called '''absorbing''' if for all <math>x\in X</math> there exists a real number ''r'' such that
:<math>\forall \alpha \in \mathbb{F} : \vert \alpha \vert \ge r \Rightarrow x \in \alpha S</math>
with
:<math>\alpha S := \{ \alpha s \mid s \in S\}</math>

== Examples ==

*In a [[semi normed vector space]] the [[unit ball]] is absorbing.

== Properties ==

*The finite [[intersection (set theory)|intersection]] of absorbing sets is absorbing

==See also ==
*[[Algebraic interior]]
*[[Bounded set (topological vector space)]]

==References==
* {{cite book |last=Robertson |first=A.P. |coauthors= W.J. Robertson |title= Topological vector spaces |series=Cambridge Tracts in Mathematics |volume=53 |year=1964 |publisher= [[Cambridge University Press]] | page=4}}
* {{cite book | last = Schaefer | first = Helmuth H. | year = 1971 | title = Topological vector spaces | series=[[Graduate Texts in Mathematics|GTM]] | volume=3 | publisher = Springer-Verlag | location = New York | isbn = 0-387-98726-6 | page=11 }}

{{Functional Analysis}}

{{Mathanalysis-stub}}

[[Category:Functional analysis]]

[[fr:Ensemble absorbant]]

Phosphoribosylaminoimidazolesuccinocarboxamide synthase

2014-01-08T19:12:08Z

86.160.126.67: grammar

{{enzyme
| Name = serine-tRNA ligase
| EC_number = 6.1.1.11
| CAS_number = 9023-48-7
| IUBMB_EC_number = 6/1/1/11
| GO_code = 0004828
| image =
| width =
| caption =
}}
In [[enzymology]], a '''serine-tRNA ligase''' ({{EC number|6.1.1.11}}) is an [[enzyme]] that [[catalysis|catalyzes]] the [[chemical reaction]]

:ATP + L-serine + tRNASer <math>\rightleftharpoons</math> AMP + diphosphate + L-seryl-tRNASer

The 3 [[substrate (biochemistry)|substrates]] of this enzyme are [[adenosine triphosphate|ATP]], [[L-serine]], and [[tRNA(Ser)]], whereas its 3 [[product (chemistry)|products]] are [[adenosine monophosphate|AMP]], [[diphosphate]], and [[L-seryl-tRNA(Ser)]].

This enzyme belongs to the family of [[ligase]]s, to be specific those forming carbon-oxygen bonds in aminoacyl-tRNA and related compounds. The systematic name of this enzyme class is '''L-serine:tRNASer ligase (AMP-forming)'''. Other names in common use include '''seryl-tRNA synthetase''', '''SerRS''', '''seryl-transfer ribonucleate synthetase''', '''seryl-transfer RNA synthetase''', '''seryl-transfer ribonucleic acid synthetase''', and '''serine translase'''. This enzyme participates in [[glycine, serine and threonine metabolism]] and [[aminoacyl-trna biosynthesis]].

==Structural studies==

As of late 2007, 13 [[tertiary structure|structures]] have been solved for this class of enzymes, with [[Protein Data Bank|PDB]] accession codes {{PDB link|1SER}}, {{PDB link|1SES}}, {{PDB link|1SET}}, {{PDB link|1SRY}}, {{PDB link|1WLE}}, {{PDB link|2CIM}}, {{PDB link|2CJ9}}, {{PDB link|2CJA}}, {{PDB link|2CJB}}, {{PDB link|2DQ0}}, {{PDB link|2DQ1}}, {{PDB link|2DQ2}}, and {{PDB link|2DQ3}}.

==References==
{{reflist|1}}
* {{cite journal | author = Katze JR, Konigsberg W | year = 1970 | title = Purification and properties of seryl transfer ribonucleic acid synthetase from Escherichia coli | journal = J. Biol. Chem. | volume = 245 | pages = 923–30 | pmid = 4906848 | issue = 5 }}
* {{cite journal | author = Makman MH and Cantoni GL | year = 1965 | title = Isolation of seryl and phenylalanyl ribonucleic acid synthetases from baker's yeast | journal = Biochemistry | volume = 4 | pages = 1434–1442 | doi = 10.1021/bi00883a031 }}
* {{cite journal | author = Webster LT and Davie EW | year = 1961 | title = Purification and properties of serine-activating enzyme from beef pancreas | journal = J. Biol. Chem. | volume = 236 | pages = 479–484 | pmid=13783661}}
* {{cite journal | author = Ohama T, Yang DC, Hatfield DL | year = 1994 | title = Selenocysteine tRNA and serine tRNA are aminoacylated by the same synthetase, but may manifest different identities with respect to the long extra arm | journal = Arch. Biochem. Biophys. | volume = 315 | pages = 293–301 | pmid = 7986071 | doi = 10.1006/abbi.1994.1503 | issue = 2 }}

{{Ligases}}

{{DEFAULTSORT:Serine-tRNA ligase}}
[[Category:EC 6.1.1]]
[[Category:Enzymes of known structure]]

{{ligase-stub}}

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Chopper (electronics)

Phosphoribosylaminoimidazolesuccinocarboxamide synthase