Search results
Results from the WOW.Com Content Network
Major secosteroid subclasses are defined by the steroid carbon atoms where this scission has taken place. For instance, the prototypical secosteroid cholecalciferol, vitamin D 3 (shown), is in the 9,10-secosteroid subclass and derives from the cleavage of carbon atoms C-9 and C-10 of the steroid B-ring; 5,6-secosteroids and 13,14-steroids are ...
Pregnenolone, an example of a hydroxysteroid. A hydroxysteroid is a molecule derived from a steroid with a hydrogen replaced with a hydroxy group . When the hydroxy group is specifically at the C3 position, hydroxysteroids are referred to as sterols , with an example being cholesterol .
The B-ring of the parent steroid is broken between C9 and C10 to yield D vitamins. A secosteroid (/ ˈ s ɛ k oʊ ˌ s t ɛ r ɔɪ d /) is a type of steroid with a "broken" ring. The word secosteroid derives from the Latin verb secare meaning "to cut", [2]: 241 and 'steroid'. Secosteroids are described as a subclass of steroids under the IUPAC ...
The 2nd structure has the hydrogens added depicted-the dark wedged bonds indicate the hydrogen atoms are coming toward the reader, the hashed bonds indicate the atoms are oriented away from the reader, and the solid (plain) bonds indicate the bonds are in the plane of the screen/paper. The middle structure shows the four carbon atoms.
Sterols are steroids in which one of the hydrogen atoms is substituted with a hydroxyl group, at position 3 in the carbon chain. They have in common with steroids the same fused four-ring core structure. Steroids have different biological roles as hormones and signaling molecules.
Depiction of a hydrogen atom showing the diameter as about twice the Bohr model radius. (Image not to scale) A hydrogen atom is an atom of the chemical element hydrogen.The electrically neutral hydrogen atom contains a single positively charged proton in the nucleus, and a single negatively charged electron bound to the nucleus by the Coulomb force.
Note the snipped stubs representing hydrogen atoms. A good example of composite models is the Nicholson approach, widely used from the late 1970s for building models of biological macromolecules. The components are primarily amino acids and nucleic acids with preformed residues representing groups of atoms. Many of these atoms are directly ...
Also carbohydrates, for example, have the same ratio (carbon:hydrogen:oxygen= 1:2:1) (and thus the same empirical formula) but different total numbers of atoms in the molecule. The molecular formula reflects the exact number of atoms that compose the molecule and so characterizes different molecules.