1.2 Structure of proteins

Question 1

formation of secondary structure

Answer 1

The secondary structure of a protein is formed by hydrogen bonding between amino acids in the same chain. Hydrogen bonds weakly attach one molecule to another due to opposite electric charges.

Question 2

first type of secondary structure

Answer 2

An a-helix is one type of secondary structure and it has a spiral shape with its R groups sticking outwards and there are hydrogen bonds between the amino acids.

Question 3

second type of secondary structure

Answer 3

B-sheet is another type of secondary structure where parts of the chain run alongside each other forming a sheet. They are usually anti-parallel, meaning that the chain run in opposite directions from each other however they can also be parallel, meaning that chains run in the same direction.

Question 4

third type of secondary structure

Answer 4

Turns are the third type of secondary structure and they reverse the direction of a polypeptide chain

Question 5

tertiary structure

Answer 5

Tertiary refers to the final 3D structure of the protein. Folding is stabilized by many different interactions between the R groups of the Amino acids like; Hydrophobic/hydrophilic interactions, LDF, Hydrogen bonds, Disulfide bridges and Ionic bonds.

Question 6

hydrophobic amino acids

Answer 6

Hydrophobic amino acids tend to cluster together on the interior of a protein away from the surface.

Hydrophobic amino acids are repelled by water.

Question 7

LDF formation

Answer 7

LDF are weak attractions between the electron cloud of atoms this occurs when the electron cloud wobbles and causes a temporary dipole and if forms LDF’s with an induced dipole.

Question 8

Disulfide bonds

Answer 8

Disulfide bond is a type of covalent bond, it is usually produced by two thiol groups joined together.

Question 9

ionic bonds

Answer 9

Ionic bond involve the electrostatic attraction between oppositely charged ions