1Diapositiva 12

Apuntes

[Diapositiva 1] Proteins Enzymes [Diapositiva 2] Amino acids and polypeptides Amino acids have a central carbon atom with four different atoms or groups linked to it: hydrogen atom amine group (-NH2 ) carboxyl group (-COOH) R group or radical (R). Amino acids (each of the twenty amino acids in proteins has a different R group) [Diapositiva 3] AMINO ACID DIVERSITY The R-group of amino acids is variable. Amino acids with hundreds of different R-groups could be produced in the laboratory. Most living organisms include only twenty of them in the polypeptides synthesized by their ribosomes. The use of the same repertoire of amino acids is one of the pieces of evidence supporting the theory that all living organisms share common ancestry. There are two extra amino acids that are considered extra variations rather than a falsification of the theory that there are twenty basic amino acids in all organisms. [Diapositiva 4] PEPTIDE BONDS AND POLYPEPTIDES Amino acids are linked together by condensation reactions [Diapositiva 5] Condensation reactions The new bond formed between the amine group of one amino acid and the carboxyl group othe next is a peptide bond . [Diapositi...