2-ch13-Thermodynamics and Chemical logic copy 4 PDF

Carbonyl group is a chemically organic functional group composed of a carbon atom double-bonded to an oxygen atom [C=O] The simplest carbonyl groups are aldehydes and ketones usually attached to another carbon compound. These structures can be found in many aromatic compounds contributing to smell a...

Carbonyl group is a chemically organic functional group composed of a carbon atom double-bonded to an oxygen atom [C=O] The simplest carbonyl groups are aldehydes and ketones usually attached to another carbon compound. These structures can be found in many aromatic compounds contributing to smell and taste.  Question Which statement is false? A. A carbanion is stabilized by an adjacent carbonyl group. B. A carbanion is an electrophile. C. In homolytic bond cleavage, each atom that was sharing the electron pair leaves with one of the electrons. D. Carbon atoms can exist in five oxidation states.  Reactions That Make or Break Carbon–Carbon Bonds heterolytic cleavage of a C–C bond yields a carb-anion and a carbo-cation combination of a nucleophilic carbanion and an electrophilic carbocation forms a C–C bond impossible reactions for the purposes of biochemistry because carbanions and carbocations are generally unstable  Chemical Properties of Carbonyl Groups the carbon of a carbonyl group is an electrophilic carbon carbonyl and imine groups form carbanions on adjoining carbons by delocalizing electrons – general acid catalysts or metal ions (Me2+) further enhance  Common Reactions that Form and Break Carbon–Carbon Bonds in aldol condensation, Claisen condensation, and decarboxylation reactions, a carbanion intermediate is stabilized by a carbonyl group Carbocations in Carbon–Carbon Bond Formation carbocation intermediates are generated by the elimination of an excellent leaving group, such as pyrophosphate Internal Rearrangements, Isomerizations, and Eliminations redistribution of electrons results in alterations without changes in the overall oxidation state of the molecule reactions include: – intramolecular oxidation-reduction – change in cis-trans arrangement at a double bond – transposition of double bonds  Elimination Reactions loss of water from an alcohol introduces a C=C bond similar reactions result from eliminations in amines Isomerization and Elimination Reactions  Free-Radical Reactions homolytic cleavage of covalent bonds to generate free radicals occurs in some pathways  Group Transfer Reactions the transfer of acyl, glycosyl, and phosphoryl groups from one nucleophile to another is common acyl group transfer involves the addition of a nucleophile to the carbonyl carbon of an acyl group to form a tetrahedral intermediate  Discussion / Principle Although thousands of different chemical reactions occur in the biosphere, most of them fall within a small set of reaction types (5 types). These include Phosphoryl group transfers Attachment of phosphoryl group(-PO42-), to intermediate to activate reaction. Catalyze by kinases Kinases, Phosphorylases, and Phosphatases