amino acids 1

Glycine

The only non-chiral amino acid.

Alpha carbon

Must have COOH and NH2 bonded to it.

L-isoforms

Proteins contain only L-isoforms; they are amphoteric.

Four major elements in amino acids

Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), (Sulfur (S)).

Primary structure of proteins

The straight linear chain of amino acids.

Secondary structure of proteins

Includes alpha helices and beta pleated sheets.

Alpha helix

A coiled structure in proteins with the backbone inside and side chains projecting outward.

Beta pleated sheets

Chains of amino acids lying side by side with hydrogen bonds oriented towards the long axis.

Tertiary structure of proteins

Involves van der Waals forces, hydrogen bonds, and ionic bonds, containing secondary structures.

Quaternary structure of proteins

Subunits joined by noncovalent bonds.

Hemoglobin

A molecule consisting of four globin chains joined by noncovalent bonds.

Functions of amino acids

Include precursors for metabolites, components of lipids, and roles as neurotransmitters.

Ionizable properties of COOH

COOH can donate a proton to become COO-.

Ionizable properties of NH2

NH2 can accept a proton to become NH3+.

Trypsinogen

Converted to trypsin by the enzyme enteropeptidase.

Classification of amino acids

Based on reactivities of R groups, catabolic products, and whether they are essential or non-essential.

Four major reactions of amino acids

Transamination, transdeamination, oxidative deamination, decarboxylation.

Mnemonic for non-polar amino acids

GAVI Is Like My Fat Pro Twin (Glycine, Alanine, Valine, Isoleucine, Leucine, Methionine, Phenylalanine, Proline, Tryptophan).

Mnemonic for polar amino acids

Santa's Team Crafts Yearly New Quilts (Serine, Threonine, Cysteine, Tyrosine, Asparagine, Glutamine).

Mnemonic for acidic amino acids

A Goal (Aspartate, Glutamate).

Mnemonic for basic amino acids

Long And Hard (Lysine, Arginine, Histidine).

Phenylalanine and tryptophan

Aromatic and non-polar amino acids.

Tyrosine

An aromatic amino acid that is ionizable and involved in hydrogen bonding.

Conditionally essential amino acids

Includes arginine, histidine, phenylalanine, methionine, and cysteine.

Amino acids with aliphatic side chains

Include glycine, alanine, valine, leucine, and isoleucine.

Hydroxyl group containing amino acids

Serine, threonine, and tyrosine.

Sulfur containing amino acids

Cysteine with sulfhydryl and methionine with thioether groups.

Acidic amino acids and their amides

Include aspartic acid, glutamic acid, and their respective amides asparagine and glutamine.

Peptides

Oligopeptides (2-10 AA units) and polypeptides (11-100 AA units) leading to proteins (over 100 AA units).