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. Proteins can be made of one or many polypeptides.

Question 3

Proteome

Answer 3

All the proteins that are expressed by a cell or organism at a given time.

Question 4

Enzyme

Answer 4

An organic molecule, typically a protein, that catalyses specific reactions.

Question 5

Peptide hormone

Answer 5

A protein signalling molecule that regulates physiology or behaviour.

Question 6

Antibody

Answer 6

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 7

Carboxyl group

Answer 7

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

Question 8

Amino group

Answer 8

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

Question 9

R-group

Answer 9

The variable portion of an amino acid molecule. It can be one of twenty variations and determines the identity of the amino acid.

Question 10

Hydrophobic

Answer 10

Having the tendency to repel and be insoluble in water.

Question 11

Hydrophilic

Answer 11

Having the tendency to be attracted to and dissolve in water.

Question 12

Hydrophilic

Answer 12

Having the tendency to be attracted to and dissolve in water.

Question 13

Monomer

Answer 13

A molecule that is the smallest building block of a polymer.

Question 14

Polymer

Answer 14

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

Question 15

Condensation reaction

Answer 15

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

forms via a peptide bond

Question 16

Peptide bond

Answer 16

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

Question 17

Primary structure

Answer 17

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

Question 18

Secondary structure

Answer 18

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

Question 19

Tertiary structure

Answer 19

Formed when secondary structures fold further by forming bonds between r-groups and amino acids. Creating the functional 3D shape of a polypeptide chain.

Question 20

Quaternary structure

Answer 20

2 or more polypeptide chains with tertiary structures bond together or other non-protein groups are added to form a fully functional protein

Question 21

Alpha helix

Answer 21

An organised coiled secondary structure of proteins.

Question 22

Beta-pleated sheet

Answer 22

An organised folded secondary structure of proteins.

Question 23

Random coil

Answer 23

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

Question 24

Disulphide bond

Answer 24

A strong covalent bond occurring between two sulphur atoms.

Question 25

Prosthetic group

Answer 25

A non-protein group bound to a protein. For example, a vitamin or ion.

Question 26

what is the structure of an Amino Acid

Answer 26

Amino Group - Central Carbon - Carboxyl Group
I
R- group