Lesson 10: ACD ChemSketch
The thirteen amino acid in the protein CDD_BACSU
The amino acid alanine and its L- and D-isomers formulae
The spatial structure of L- and D-forms of amino acid alanine
L-isomer of alanine
D-isomer of alanine
Consider the L-form. From the plane formed by atoms N-Cα-C the atom H and the group CH3 are out. his case the hydrogen atom is directed at us (i.e. the bond goes above the plane of the figure), the group of CH3 - from us (i.e. the bond goes under the plane of the figure). In D-form the atom of hydrogen out of the plane away from us, a methyl group - to us. Thus, the difference between these isomers is in the mutual arrangement of H and CH3. And the transition from L-from to D-form and vice versa is impossible.
The chemical reaction of the dipeptide formation
The formation of aspargilarginina
Full-sized picture.
Peptide bond is a type of an amide bond that occurs during the formation of peptides and proteins in the interaction of α-amino group (—NH2) of one amino acid with the α-carboxyl (—ÑÎÎÍ) of another amino acid. Of the two amino acids (in this case, it is aspargin and arginine) dipeptide (a chain of two amino acids) and a water molecule are produced. More long chains of amino acids polypeptides and proteins are generated by the same pattern.
Scheme of the peptide
Scheme of the peptide
with a dedicated skeleton
Formula of fikocianobilin
Formula of fikocianobilin
For fun, we can construct three-dimensional structure of fikocianobilin:
The spatial structure of fikotsianobilina
The spatial structure of fikotsianobilina