2A Protein Structure and Function

Question 1

protein

Answer 1

a biomacromolecule made of amino acid chains folded into a 3D shape

Question 2

polypeptide

Answer 2

a long chain of amino acids

Question 3

enzyme

Answer 3

an organic molecule, typically a protein, that catalyses specific reactions

Question 4

peptide hormone

Answer 4

a protein signalling molecule that regulates physiology or behaviour

Question 5

antibody

Answer 5

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

Question 6

carboxyl group

Answer 6

the functional group on amino acid molecules that contains a hydroxyl group (OH) and an oxygen double-bonded to a carbon atom

Question 7

amino group

Answer 7

the functional group on amino acid molecules that is made up of one nitrogen and two hydrogens (NH2)

Question 8

R-group

Answer 8

the variable portion of an amino acid molecule, it can be one of twenty variations and determines the identity of the amino acid

Question 9

hydrophobic

Answer 9

repels water

Question 10

hydrophilic

Answer 10

attracted to water

Question 11

monomer

Answer 11

a molecule that is the smallest building block of a polymer

Question 12

polymer

Answer 12

a large molecule that is made up of small, repeated monomer subunits

Question 13

condensation reaction

Answer 13

a reaction where two monomers join to form a larger molecule, producing water as a by-product

Question 14

peptide bond

Answer 14

the chemical bond linking two amino acids

Question 15

primary structure

Answer 15

the first level of protein structure, which refers to the sequence of amino acids in a polypeptide chain

Question 16

secondary structure

Answer 16

the level of protein structure where the amino acid chain forms either alpha-helices, beta-pleated sheets or random coils

Question 17

tertiary structure

Answer 17

the functional 3D shape of a polypeptide chain

Question 18

quaternary structure

Answer 18

the level of protein structure where multiple polypeptide chains bond together, or other non-protein groups are added to form a fully functional protein

Question 19

alpha helix

Answer 19

an organised coiled secondary structure of proteins

Question 20

beta-pleated sheet

Answer 20

an organised folded secondary structure of proteins

Question 21

random coil

Answer 21

an irregular secondary structure of proteins that is neither an alpha helix nor a beta-pleated sheet

Question 22

disulphide bond

Answer 22

a strong covalent bond occurring between two sulphur atoms

Question 23

prosthetic group

Answer 23

a non-protein group bound to a protein (eg. a vitamin or ion)