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Topic: Carboxyl group


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  AllRefer.com - carboxyl group (Organic Chemistry) - Encyclopedia
Carboxylic acids are compounds whose molecules contain a carboxyl group that is joined to a hydrogen atom, an alkyl group, or an aryl group by a single bond to its carbon atom.
The four main types of reactions of carboxylic acids are chiefly due to either the weak acidity of the hydroxyl hydrogen or to the difference in electronegativity between carbon and oxygen.
The second and third types are similar to reactions of the carbonyl group; the carboxyl group may be thought of as a carbonyl group joined to a hydroxyl group.
reference.allrefer.com /encyclopedia/C/carbxylgr.html   (324 words)

  
 Class 560: ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES / U.S. Patent Classification Definitions
Esters of polycarboxylic acids where one or more of the carboxyl groups are unesterified are classified with the polycarboxylic acid esters where all carboxyl groups may be in the free acid form or may be present as salts or as acid halides.
Compounds wherein the carboxyl group is esterified by a phenolic hydroxyl group.
Processes wherein the ester is prepared through formation of a carboxyl group of a starting material by reaction with a carbonylating agent such as carbon monoxide either in the presence of an alcohol or by subsequent esterification of the formed acid.
www.uspto.gov /web/offices/ac/ido/oeip/taf/def/560.htm   (7377 words)

  
 Proteins   (Site not responding. Last check: 2007-11-05)
A central carbon, the alpha carbon, carries a carboxyl group, a hydrogen atom, and an amino group, and a variable R group.
When the R group is unknown or does not need to be specified, it is simply indicated by R. Amino acids can be classified as hydrophobic or hydrophilic according to the nature of their R groups.
Hydrophilic R groups may have amino or carboxyl groups or hydroxyl groups and therefore be either polarized or carry a positive or negative charge.
campus.northpark.edu /biology/cell/proteins.html   (666 words)

  
 Introduction of a Carboxyl Group in the First Transmembrane Helix of Escherichia coli F1Fo ATPase Subunit c and ...
E and e represent the essential carboxyl group and the carboxyl group at position 188, respectively.
Two carboxyl groups in transmembrane helices of subunit c are found in several pathogenic bacteria and in the related vacuolar ATPase.
ATP synthases: probing the liganding groups for Na and Li in the c subunit of the ATP synthase from Propionigenium modestum.
jb.asm.org /cgi/content/full/183/5/1524   (3438 words)

  
 Carboxylic Acid Reactivity
Both the carboxyl group and the carboxylate anion are stabilized by resonance, but the stabilization of the anion is much greater than that of the neutral function, as shown in the following diagram.
In the carboxylate anion the two contributing structures have equal weight in the hybrid, and the C–O bonds are of equal length (between a double and a single bond).
Reactions in which the hydroxyl group of a carboxylic acid is replaced by another nucleophilic group are important for preparing functional derivatives of carboxylic acids.
www.cem.msu.edu /~reusch/VirtualText/crbacid1.htm   (3475 words)

  
 GROUP - Definition
A cluster, crowd, or throng; an assemblage, either of persons or things, collected without any regular form or arrangement; as, a group of men or of trees; a group of isles.
See {Group}, n.] To form a group of; to arrange or combine in a group or in groups, often with reference to mutual relation and the best effect; to form an assemblage of.
The difficulty lies in drawing and disposing, or, as the painters term it, in grouping such a multitude of different objects.
www.hyperdictionary.com /dictionary/group   (320 words)

  
 Process of hardening protein-containing photographic layers with a mixture of a carboxyl group-activating, low ...
In the case of proteins containing carboxyl and amino groups, the reaction continues and the activated carboxyl groups together with the amino groups, form peptide bonds.
The low molecular weight fast-acting, carboxyl group-activating hardening agents are taken from the group consisting of peptide reagents in general, preference being given to carbamoylpyridinium salts, carbamoyloxypyridinium salts, isoxazolium salts, dihydroquinoline derivatives, and especially carbodiimides.
The substituent groups of the polymeric hardener activate the carboxyl groups present in gelatin near the interface and they are modified themselves thereby.
www.freepatentsonline.com /4047957.html   (5707 words)

  
 Qualitative distinction of carboxyl group distributions in pectins with ruthenium red
The dye group binds between the carboxyl oxygen of one galacturonide moiety and a hydroxyl oxygen of an adjacent neighbor galacturonide in the pectate chain.
Other reports on the different behaviors of free carboxyl groups along the pectin chains (Kohn et al., 1968, 1983; Ishii et al., 1979; Tuerena et al., 1982, 1984) also presumed in advance that higher plant pectinesterase-treated pectin was of blockwise type and alkali-treated pectins were of random type in carboxyl group distributions.
Ruthenium red is a dye which selectively binds to the intramolecular (not intermolecular) spaces of carboxyl groups of pectin and shows little binding to alginic acid carboxyl groups, which have a different internal configuration of carboxyl groups.
ejournal.sinica.edu.tw /bbas/content/1999/2/bot402-02.html   (2111 words)

  
 carboxyl group on Encyclopedia.com   (Site not responding. Last check: 2007-11-05)
(kärbŏk´sĬl), in chemistry, functional group that consists of a carbon atom joined to an oxygen atom by a double bond and to a hydroxyl group, OH, by a single bond.
The second and third types are similar to reactions of the carbonyl group ; the carboxyl group may be thought of as a carbonyl group joined to a hydroxyl group.
Carboxyl terminated polyamide 12 chain extension by reactive extrusion using a dioxazoline coupling agent.
www.encyclopedia.com /html/c1/carbxylgr.asp   (511 words)

  
 Carboxyl -- Facts, Info, and Encyclopedia article   (Site not responding. Last check: 2007-11-05)
Carboxyl groups are characteristic constituents of more complex functional groups such as (An organic acid characterized by one or more carboxyl groups) carboxylic acids and (Any organic compound containing the group -CONH2) amides.
They are structurally similar to the (The bivalent radical CO) carbonyl group.
The C=O stretch of carboxyl groups can be identified (Click link for more info and facts about spectroscopically) spectroscopically by a sharp peak in the (The infrared part of the electromagnetic spectrum; electromagnetic wave frequencies below the visible range) infrared between 1700 and 2100 cm
www.absoluteastronomy.com /encyclopedia/c/ca/carboxyl.htm   (120 words)

  
 [No title]   (Site not responding. Last check: 2007-11-05)
the carboxyl group yields H+ ions because it is a(n)____________.
The folding of the protein results at this level because the amino group of an amino acid in one plane hydrogen bonds with the carboxyl group of an amino acid in another plane.
Sulfhydryl groups are important in forming the 3 D structure of protein by forming disulfide bridges (S- S) Draw the compound cysteine, one of the essential amino acids._______________ Q.
faculty.uncfsu.edu /jraynor/Module2.doc   (1030 words)

  
 sciforums.com - Lipids   (Site not responding. Last check: 2007-11-05)
Phosphate and carboxyl groups are both polar groups, but the majority of the molecule is in the long carbon-hydrogen chains, which are non-polar.
The commonest water-solubilising group in nonionics is the ethoxylate chain (polyoxyethylene chain) produced by addition of ethylene oxide to a hydrophobe such as fatty alcohol, fatty acid etc..
An important group of naturally occurring substances consisting of the glycerides of higher fatty acids (eg palmitic acid, stearic acid, oleic acid) which are solid at room temperature (by contrast withn oils which are liquid or semi-solid).
www.sciforums.com /archive/index.php/t-41465   (1782 words)

  
 CARBOXYL GROUP - Definition
One of the oxygens is double-bonded to the carbon atom, making it a carbonyl group, and the other oxygen is single bonded to the carbon on one side, and single bonded to the hydrogen on the other.
The remaining bond on the carbon atom is attached to the rest of the molecule.
Organic molecules containing carboxyl groups are an important, major group of compounds studied in the field of organic chemistry.
www.hyperdictionary.com /dictionary/carboxyl+group   (83 words)

  
 PPS 96' - PROPERTIES OF THE 20 AMINO ACIDS   (Site not responding. Last check: 2007-11-05)
When an amino acid is incorporated into a polypeptide by the ribosome at say position i in the sequence, it undergoes a condensation reaction in which the carboxyl group of the preceding amino acid (i-1) forms an amide (or peptide) bond with the amino group residue i.
In the next elongation cycle of the ribosome, the carboxyl group of residue i becomes covalently linked to the amino group of residue i+1 in the final sequence by another peptide bond.
In each condensation reaction an -OH group is essentially lost from the participating carboxyl group and a hydrogen is lost from the amino group, ie water is eliminated.
www.cryst.bbk.ac.uk /PPS2/course/section2/SideChains/primary1.html   (264 words)

  
 carboxyl group   (Site not responding. Last check: 2007-11-05)
Carboxylic acids are compounds whose molecules contain a carboxyl group that is joined to a hydrogen atom, an
The four main types of reactions of carboxylic acids are chiefly due to either the weak acidity of the hydroxyl hydrogen or to the difference in
; the carboxyl group may be thought of as a carbonyl group joined to a hydroxyl group.
www.infoplease.com /ce6/sci/A0810381.html   (288 words)

  
 Carbapenem antibiotics - Patent 4746736
The reaction to establish the leaving group at the 2-position of intermediate III is advantageously carried out in the presence of a base such as diisopropylethylamine, triethylamine, 4-dimethylaminopyridine, or the like, at a temperature of from about -20.degree.
The allyl protecting group may be removed with a catalyst comprising a mixture of a palladium compound and triphenylphosphine in an aprotic solvent such as tetrahydrofuran, diethyl ether or methylene chloride.
The allyl protecting group may be removed by using a catalyst comprising a mixture of a palladium compound and triphenyl phosphine in a suitable aprotic solvent such as tetrahydrofuran, methylene chloride or diethyl ether.
www.freepatentsonline.com /4746736.html   (8853 words)

  
 #1 Site For Learning Chemistry
The functional group —COOH is called the carboxyl group and thus the organic acids are also called as carboxylic acids.
The bonds in a carboxyl group are such that the C has a double bond to O and a single bond to which the hydroxyl group OH is attached.
The carboxyl group —COOH indicates that it is an acid.
home.att.net /~cat6a/org_chem-IX.htm   (1247 words)

  
 Isoelectric point - Wikipedia, the free encyclopedia
For an amino acid with only one amine and one carboxyl group, the pI can be calculated from the pKa's of this molecule.
For amino acids with more than two ionizable groups such as lysine for example, the same formula is used but this time, the two pKa's used are those of the two groups that lose and gain a charge from the neutral form of the amino acid.
Proteins can be separated according to their isoelectric point in a process known as isoelectric focusing.
en.wikipedia.org /wiki/Isoelectric_point   (260 words)

  
 [No title]
 Carboxylic acids are classified according to the substituent that is bonded to the carboxyl carbon: Aliphatic acids have an alkyl group bound to the carboxyl group.
Reactions of Carboxylic Acids (and Derivatives) Ketones and aldehydes have a carbonyl group and undergo nucleophilic addition, whereas carboxylic acids (and their derivatives) under nucleophilic acyl substitution - this is where one nucleophile replaces another on the acyl carbon.
The carbonyl group of a carboxylic acid is not sufficiently electrophilic to be attacked by the alcohol.
crab.rutgers.edu /~alroche/Ch20.doc   (2891 words)

  
 carboxyl group
A chemical group found in all carboxylic acids.
It consists of a carbon atom joined by covalent bonds to two oxygen atoms, one of which in turn is covalently bonded to a hydrogen atom.
One valence electron on the carbon is available for bonding to another atom so that the carboxyl group can form part of a larger molecule.
www.daviddarling.info /encyclopedia/C/carboxyl.html   (135 words)

  
 Reactivity of the carboxyl group (from lipid) --  Encyclopædia Britannica   (Site not responding. Last check: 2007-11-05)
The low water solubility of fatty acids, which are members of a large group of organic acids known as carboxylic acids, makes difficult the determination of their properties as acids.
In organic chemistry the concept of functional groups is useful as a basis for classification of large numbers of compounds according to their reactions.
The elements in a group have similarities in the electronic configuration of their atoms, and thus they exhibit somewhat related physical and chemical properties.
www.britannica.com /eb/article-72644?tocId=72644   (850 words)

  
 Carboxyl : Carboxyl group   (Site not responding. Last check: 2007-11-05)
A carboxyl group is a functional group consisting of a carbon atom and an oxygen atom doubly bonded to each other.
Carboxyl groups are characteristic constituents of more complex functional groups such as carboxylic acids, ketones, aldehydes, and amides.
It uses material from the wikipedia article Carboxyl : Carboxyl group.
www.eurofreehost.com /ca/Carboxyl_group.html   (145 words)

  
 ESTERS - Online Information article about ESTERS
group has been replaced by an alkyl or aryl group.
present in the ortho positions to the carboxyl group.
In such a case the ester is best prepared by the action of an alkyl halide on the silver salt of the acid, and when once prepared, can only be hydrolysed with great difficulty.
encyclopedia.jrank.org /EMS_EUD/ESTERS.html   (1151 words)

  
 Azo dyestuffs having a carboxyl group and a substituted sulfonylimino group in the coupling component - Patent 4179435
R is C.sub.1 -C.sub.5 alkyl or a group of the formula ##STR45## where R.sub.3 and R.sub.4 are C.sub.1 -C.sub.5 alkyl, or R.sub.3 and R.sub.4 together with the nitrogen to which they are attached, represent morpholino or piperidino.
Suitable swelling agents are aromatic carboxylic acids, for example salicylic acid, phenols, such as, for example, o- or p-hydroxydiphenyl, aromatic halogen compounds, such as o-dichlorobenzene, or diphenyl.
In addition to a disperse dyestuff which is free from carboxyl groups, the printing paste may also contain dyestuffs of other dyeing categories, for example water-soluble or water-insoluble dyestuffs with fibre-reactive groups, sich as di- or monochlorotriazine groups, chloroacetylamino groups and acrylic amide groups.
www.freepatentsonline.com /4179435.html   (2602 words)

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