2A Protein Structure and Function Flashcards
protein
a biomacromolecule made of amino acid chains folded into a 3D shape
polypeptide
a long chain of amino acids
enzyme
an organic molecule, typically a protein, that catalyses specific reactions
peptide hormone
a protein signalling molecule that regulates physiology or behaviour
antibody
a protein produced by plasma cells during the adaptive immune response that is specific to an antigen and combats pathogens in a variety of ways
carboxyl group
the functional group on amino acid molecules that contains a hydroxyl group (OH) and an oxygen double-bonded to a carbon atom
amino group
the functional group on amino acid molecules that is made up of one nitrogen and two hydrogens (NH2)
R-group
the variable portion of an amino acid molecule, it can be one of twenty variations and determines the identity of the amino acid
hydrophobic
repels water
hydrophilic
attracted to water
monomer
a molecule that is the smallest building block of a polymer
polymer
a large molecule that is made up of small, repeated monomer subunits
condensation reaction
a reaction where two monomers join to form a larger molecule, producing water as a by-product
peptide bond
the chemical bond linking two amino acids
primary structure
the first level of protein structure, which refers to the sequence of amino acids in a polypeptide chain
secondary structure
the level of protein structure where the amino acid chain forms either alpha-helices, beta-pleated sheets or random coils
tertiary structure
the functional 3D shape of a polypeptide chain
quaternary structure
the level of protein structure where multiple polypeptide chains bond together, or other non-protein groups are added to form a fully functional protein
alpha helix
an organised coiled secondary structure of proteins
beta-pleated sheet
an organised folded secondary structure of proteins
random coil
an irregular secondary structure of proteins that is neither an alpha helix nor a beta-pleated sheet
disulphide bond
a strong covalent bond occurring between two sulphur atoms
prosthetic group
a non-protein group bound to a protein (eg. a vitamin or ion)
