dihedral angle
51Platonic solid — In geometry, a Platonic solid is a convex polyhedron that is regular, in the sense of a regular polygon. Specifically, the faces of a Platonic solid are congruent regular polygons, with the same number of faces meeting at each vertex; thus, all… …
52Tetrahedron — For the academic journal, see Tetrahedron (journal). Regular Tetrahedron (Click here for rotating model) Type Platonic solid Elements F = 4, E = 6 V = 4 (χ = 2) Faces by s …
53Wing configuration — For aircraft configurations in general, including fuselage, tail and powerplant configuration, see Aircraft. For rotary winged aircraft types, see Rotorcraft. For direct lift and compound or hybrid types, see Powered lift. Fixed wing aircraft,… …
54Alpha helix — A common motif in the secondary structure of proteins, the alpha helix (α helix) is a right handed coiled conformation, resembling a spring, in which every backbone N H group donates a hydrogen bond to the backbone C=O group of the amino acid… …
55Flight dynamics — is the science of air and space vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle s center of mass, known as pitch , roll and yaw… …
56Polyproline helix — In proteins, a left handed polyproline II helix (PPII, poly Pro II) is formed when sequential residues all adopt (φ,ψ) backbone dihedral angles of roughly ( 75°, 150°) and have trans isomers of their peptide bonds. Similarly, a more compact right …
57Semiregular 4-polytope — In geometry, a semiregular 4 polytope (or polychoron) is a 4 dimensional polytope which is vertex transitive (i.e. the symmetry group of the polytope acts transitively on the vertices) and whose cells are regular polyhedra. These represent a… …
58Pi helix — Side view of a standard π helix of L alanine residues in atomic detail. Two hydrogen bonds to the same peptide group are highlighted in magenta; the oxygen hydrogen distance is 1.65 Å (165 pm). The protein chain runs upwards, i.e., its N terminus …
59Coplanarity — In geometry, a set of points in space is coplanar if all the points lie in the same geometric plane. For example, three distinct points are always coplanar; but a fourth point or more added in space can exist in another plane, incoplanarly.… …
60Dodecahedron — Regular Dodecahedron (Click here for rotating model) Type Platonic solid Elements F = 12, E = 30 V = 20 (χ = 2) Faces by sides 12{5} …
