What
is the only amino acid with a substituted alpha amino group? the
presence of this amino acid influences protein folding byforcing a
bend in the chain- draw its structure.

Proline

Explanation:

Proline's unique characteristic it's that it is the only amino acid where the side chain is connected to the backbone twice forming a nitrogen-containing ring, this means it has a substituted alpha-amino group. This characteristic is important to the structure of proteins, because, contrary to glycin which adopts many main chain conformations, proline if most commonly found in tight turns because of its rigidity.

Hope you find this information useful! Good luck!

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.