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Tertiary structure refers to the locations of the atoms in three-dimensional space, taking into consideration geometrical and steric constraints. It is a higher order than the secondary structure, in which large-scale folding in a linear polymer occurs and the entire chain is folded into a specific 3-dimensional shape.
Tertiary carbon radicals have three σ C-H bonds that donate, secondary radicals only two, and primary radicals only one. Therefore, tertiary radicals are the most stable and primary radicals the least stable. The relative stabilities of tertiary, secondary, primary and methyl radicals can be explained by hyperconjugation
Primary is a term used in organic chemistry to classify various types of compounds (e.g. alcohols, alkyl halides, amines) or reactive intermediates (e.g. alkyl radicals, carbocations). Red highlighted central atoms in various groups of chemical compounds.
Compounds bearing carbon–hydrogen bonds react with radicals in the order primary < secondary < tertiary < benzyl < allyl reflecting the order in C–H bond dissociation energy [4] Many stabilizing effects can be explained as resonance effects, an effect specific to radicals is the captodative effect.
Secondary (inset) and tertiary structure of tRNA demonstrating coaxial stacking. [20] Coaxial stacking, otherwise known as helical stacking, is a major determinant of higher order RNA tertiary structure. Coaxial stacking occurs when two RNA duplexes form a contiguous helix, which is stabilized by base stacking at the interface of the two helices.
A radical abstracts a hydrogen atom from methane, leaving a primary methyl radical. The methyl radical then abstracts Cl • from Cl 2 to give the desired product and another chlorine radical. Methane chlorination: propagation The radical will then participate in another propagation reaction: the radical chain. Other products such as CH 2 Cl 2 ...
Primary, secondary, and tertiary ammonium salts serve the same function but are less lipophilic. They are also used as phase-transfer catalysts and surfactants . An unusual class of organic ammonium salts is derivatives of amine radical cations, [•NR 3 ] + such as tris(4-bromophenyl)ammoniumyl hexachloroantimonate .
The primary structure of a biopolymer is the exact specification of its atomic composition and the chemical bonds connecting those atoms (including stereochemistry).For a typical unbranched, un-crosslinked biopolymer (such as a molecule of a typical intracellular protein, or of DNA or RNA), the primary structure is equivalent to specifying the sequence of its monomeric subunits, such as amino ...