B1.2 HL only

Question 1

Primary structure

Answer 1

the sequence of amino acids linked together to form a polypeptide chain

Question 2

Secondary structure

Answer 2

local folded structures that form within a polypeptide due to interactions between atoms of the backbone

Question 3

Tertiary structure

Answer 3

the overall three-dimensional arrangement of its polypeptide chain in space. It is generally stabilized by outside polar hydrophilic hydrogen and ionic bond interactions, and internal hydrophobic interactions between nonpolar amino acid side chains

Question 4

Quaternary structure

Answer 4

the arrangement of multiple protein chains or subunits, held together by hydrogen bonds and van der Waals forces, to form a functional protein

Question 5

Alpha helix

Answer 5

a sequence of amino acids in a protein that are twisted into a coil (a helix). Three-dimensional structure of an alpha helix in the protein crambin

Question 6

Beta-pleated sheet

Answer 6

a common motif of the regularprotein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a generally twisted, pleated sheet

Question 7

Ionic bonds

Answer 7

type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom.

Question 8

Disulfide bonds

Answer 8

covalent interactions formed between the sulfur atoms of two cysteine residues

Question 9

cysteine

Answer 9

a non-essential amino acidand is present in thiol proteins, peptides of living organisms, which plays an important role in the biosynthesis of glutathione, trypanothione and other important metabolites

Question 10

Hydrophobic interactions

Answer 10

the non-covalent force where nonpolar species tend to cluster in water in order to decrease the overall interfacial area between the hydrophobic species and water

Question 11

Hydrophilic interactions

Answer 11

one that is able to interact with water. The term hydrophilic literally means water loving.

Question 12

Hydrogen bonds

Answer 12

an interaction in which a hydrogen atom bridges two electronegative atoms

Question 13

prosthetic group

Answer 13

the non-amino acid component that is part of the structure of the heteroproteins orconjugated proteins, being tightly linked to theapoprotein

Question 14

Collagen

Answer 14

protein molecules made up of amino acids. It provides structural support to the extracellular space of connective tissues. Due to its rigidity and resistance to stretching, it is the perfect matrix for skin, tendons, bones, and ligaments

Question 15

Insulin

Answer 15

A hormone made by theislet cellsof the pancreas. Insulin controls the amount of sugar in the blood by moving it into the cells, where it can be used by the body for energy

Question 16

hexamers

Answer 16

a macromolecular structure consisting of six noncovalently associated identical or nonidentical subunits.

Question 17

Haemoglobin

Answer 17

A protein inside red blood cells that carries oxygen from the lungs to tissues and organs in the body and carries carbon dioxide back to the lungs

Question 18

haem group

Answer 18

an essential prosthetic group in proteins that is necessary as a subcellular compartment to perform diverse biological functions like hemoglobin and myoglobin

Question 19

Fibrous proteins

Answer 19

structural or storage proteins that are typically inert and water-insoluble

Question 20

globular proteins

Answer 20

spherical (“globe-like”) proteins and are one of the common protein types