Proteins

Front 1

alpha-helix structure (α-helix)

Back 1

type of secondary structure of proteins formed by folding of the polypeptide into a helix shape with hydrogen bonds stabilizing the structure

Front 2

amino acid

Back 2

monomer of a protein; has a central carbon or alpha carbon to which an amino group, a carboxyl group, a hydrogen, and an R group or side chain is attached; the R group is different for all 20 amino acids

Front 3

beta-pleated sheet (β-pleated)

Back 3

secondary structure found in proteins in which “pleats” are formed by hydrogen bonding between atoms on the backbone of the polypeptide chain

Front 4

chaperone

Back 4

(also, chaperonin) protein that helps nascent protein in the folding process

Front 5

denaturation

Back 5

loss of shape in a protein as a result of changes in temperature, pH, or exposure to chemicals

Front 6

enzyme

Back 6

catalyst in a biochemical reaction that is usually a complex or conjugated protein

Front 7

hormone

Back 7

chemical signaling molecule, usually protein or steroid, secreted by endocrine cells that act to control or regulate specific physiological processes

Front 8

peptide bond

Back 8

bond formed between two amino acids by a dehydration reaction

Front 9

polypeptide

Back 9

long chain of amino acids linked by peptide bonds

Front 10

primary structure

Back 10

linear sequence of amino acids in a protein

Front 11

protein

Back 11

biological macromolecule composed of one or more chains of amino acids

Front 12

quaternary structure

Back 12

association of discrete polypeptide subunits in a protein

Front 13

secondary structure

Back 13

regular structure formed by proteins by intramolecular hydrogen bonding between the oxygen atom of one amino acid residue and the hydrogen attached to the nitrogen atom of another amino acid residue

Front 14

tertiary structure

Back 14

three-dimensional conformation of a protein, including interactions between secondary structural elements; formed from interactions between amino acid side chains