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. Proteins can be made of one or many polypeptides.
Proteome
All the proteins that are expressed by a cell or organism at a given time.
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
Having the tendency to repel and be insoluble in water.
Hydrophilic
Having the tendency to be attracted to and dissolve in water.
Hydrophilic
Having the tendency to be attracted to and dissolve in 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.
forms via a peptide bond
Peptide bond
The chemical bond linking two amino acids.
- occurs when the hydroxyl group off of the 1st AA is removed and joined with a hydrogen off of the amino group of the second AA forming water(condensation reaction)
- the remaining carboxyl and amino groups then join together
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
Formed when secondary structures fold further by forming bonds between r-groups and amino acids. Creating the functional 3D shape of a polypeptide chain.
Quaternary structure
2 or more polypeptide chains with tertiary structures 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.
