0.5
orsymbol (in enzyme kinetics) for the value of the concentration of a substrate, A, in mol dm−3, at which the velocity of the reaction, v, is half the maximum velocity, V; i.e. when v = 0.5V.[...]
50
symbol for the molar concentration of an agonist that produces 50% of the maximal possible effect of that agonist. Other percentage values ([A]20, [A]40, etc.) can be specified. The action of the ...
2′-5′A
symbol for any member of a series of oligonucleotides of the general formula pa A[2′p5′A]n, where p and A are phosphoric and adenosine residues, respectively, and a and n are ...
A
symbol for1 acid‐catalysed (of a reaction mechanism).2 a residue of the α‐amino acid l‐alanine (alternative to Ala).3 a residue of the base adenine in a nucleic‐acid sequence.[...]
a
symbol for1 absorption coefficient.2 acceleration (in vector equations it is printed in bold italic (a).3 activity (def. 3).4 van der Waals coefficient.5 as subscript, denotes affinity.[...]
A
symbol for1 absorbance.2 activity (def. 2).3 affinity.4 Helmholtz function.5 mass number/nucleon number.
(A + T)/(G + C) ratio
The ratio of the sum of the adenine plus thymine bases to the sum of the guanine plus cytosine bases in a DNA molecule or preparation. The ratio is to ...
A 2 bu
orsymbol for a residue of the α, γ‐diamino acid l‐α, γ‐diaminobutyric acid, l‐2,4‐diaminobutanoic acid.
A 2 pr
orsymbol for a residue of the α,β‐diamino acid l‐α,β‐diaminopropionic acid; l‐2,3‐diaminopropanoic acid.
A–T tailing
Homopolymer tailing of two types of duplex DNA molecule or fragment by the successive addition of adenine deoxynucleotide residues (A) to the 3′ ends of molecules of one type and ...
A23187
ora toxic and weakly antibiotic substance isolated from cultures of Streptomyces chartreusensis. It is a lipophilic 523 Da monocarboxylic acid of complex structure, two molecules of which form stable ...
AA
1 symbol for an unknown or unspecified aminoacyl group when acting as a substituent on a base or internal sugar in a (poly)nucleotide.2 abbr. for amino acid.
AAA
1 a codon in mRNA for l‐lysine.2 abbr. for ATPase associated with varied activities. See AAA protease.
