Biochemistry Success Guide-
printable
Amino Acids and Proteins
Big Picture
Biochemistry Success Guide-printable 1
, Proteins are essential macromolecules in living systems, performing vital roles
from catalysis and transport to structural support and immune defense. They are
built from 20 different L-amino acids linked sequentially by peptide (amide)
bonds, forming a linear polypeptide chain, which is the primary structure. This
sequence dictates how the chain folds into secondary structures (like α-helices
and β-pleated sheets, stabilized by backbone hydrogen bonds), then into a unique
three-dimensional tertiary structure (stabilized by side-chain interactions
including disulfide bonds, hydrogen bonds, salt bridges, and hydrophobic
interactions). For multisubunit proteins, the arrangement of multiple chains forms
the quaternary structure. Crucially, the amino acid sequence directly
determines the protein's folded structure, which in turn dictates its biological
function.
Amino Acids
Biochemistry Success Guide-printable 2
, Amino acids are the building blocks of proteins. Each has a central α-carbon
attached to a basic amino group, an acidic carboxyl group, a hydrogen atom, and
a distinctive side chain (–R).
Proline is an α-imino acid, not an α-amino acid.
Biochemistry Success Guide-printable 3
printable
Amino Acids and Proteins
Big Picture
Biochemistry Success Guide-printable 1
, Proteins are essential macromolecules in living systems, performing vital roles
from catalysis and transport to structural support and immune defense. They are
built from 20 different L-amino acids linked sequentially by peptide (amide)
bonds, forming a linear polypeptide chain, which is the primary structure. This
sequence dictates how the chain folds into secondary structures (like α-helices
and β-pleated sheets, stabilized by backbone hydrogen bonds), then into a unique
three-dimensional tertiary structure (stabilized by side-chain interactions
including disulfide bonds, hydrogen bonds, salt bridges, and hydrophobic
interactions). For multisubunit proteins, the arrangement of multiple chains forms
the quaternary structure. Crucially, the amino acid sequence directly
determines the protein's folded structure, which in turn dictates its biological
function.
Amino Acids
Biochemistry Success Guide-printable 2
, Amino acids are the building blocks of proteins. Each has a central α-carbon
attached to a basic amino group, an acidic carboxyl group, a hydrogen atom, and
a distinctive side chain (–R).
Proline is an α-imino acid, not an α-amino acid.
Biochemistry Success Guide-printable 3
