Search results
Results from the WOW.Com Content Network
The peptide backbone dihedral angles (φ, ψ) are about (–140°, 135°) in antiparallel sheets. In this case, if two atoms C α i and C α j are adjacent in two hydrogen-bonded β-strands, then they form two mutual backbone hydrogen bonds to each other's flanking peptide groups; this is known as a close pair of hydrogen bonds.
For many cases, such as trigonal pyramidal and bent, the actual angle for the example differs from the ideal angle, and examples differ by different amounts. For example, the angle in H 2 S (92°) differs from the tetrahedral angle by much more than the angle for H 2 O (104.48°) does.
In stereochemistry, a torsion angle is defined as a particular example of a dihedral angle, describing the geometric relation of two parts of a molecule joined by a chemical bond. [ 4 ] [ 5 ] Every set of three non-colinear atoms of a molecule defines a half-plane.
There are several variants of bending, where the most common is AX 2 E 2 where two covalent bonds and two lone pairs of the central atom (A) form a complete 8-electron shell. They have central angles from 104° to 109.5°, where the latter is consistent with a simplistic theory which predicts the tetrahedral symmetry of four sp 3 hybridised ...
The discovery of DNA ligase dates back to 1967 and was an important event in the field of molecular biology. [1] Ligation in the laboratory is normally performed using T4 DNA ligase. It is broadly used in vitro due to its capability of joining sticky-ended fragments as well as blunt-ended fragments. [2]
a Størmer number, since the greatest prime factor of 51 2 + 1 = 2602 is 1301, which is substantially more than 51 twice. [6] There are 51 different cyclic Gilbreath permutations on 10 elements, [7] and therefore there are 51 different real periodic points of order 10 on the Mandelbrot set. [8]
When given a protein pair to classify, RFD first creates a representation of the protein pair in a vector. [9] The vector contains all the domain types used to train RFD, and for each domain type the vector also contains a value of 0, 1, or 2. If the protein pair does not contain a certain domain, then the value for that domain is 0.
This increased p character in those orbitals decreases the bond angle between them to less than the tetrahedral 109.5°. The same logic can be applied to ammonia (107.0° HNH bond angle, with three N(~sp 3.4 or 23% s) bonding orbitals and one N(~sp 2.1 or 32% s) lone pair), the other canonical example of this phenomenon.