Protein 3D Conformation

Question 1

What are the different classifications of proteins?

Answer 1

Globular, fibrous, and membrane proteins

Question 2

Describe myoglobin

Answer 2

A monomeric, globular protein composed of 123 amino acids. Contains the prosthetic group haem.

Only two polar residues on the interior; two histidine residues.

Question 3

What does haem consist of?

Answer 3

Protoporphyrin IX and a central iron atom. The protoporphyrin is made up of four pyrrole rings linked by methine bridges to form a tetra-pyrrole ring.

Question 4

Which iron state in haem is capable of binding oxygen?

Answer 4

Fe²⁺

Question 5

The ____ in haem can form two additional bonds, one each side of the ____ _____. These binding sites are called the _____ and _____ coordination sites.

Answer 5

The **iron **in haem can form two additional bonds, one each side of the haem plane. These binding sites are called the fifth and sixth coordination sites.

Question 6

In myoglobin, the _____ coordination site is occupied by the _______ ring of a ________ residue from the protein. The ________ is referred to as the proximal ________.

Answer 6

In myoglobin, the **fifth **coordination site is occupied by the **imidazole **ring of a **histidine **residue from the protein. The **histidine **is referred to as the proximal histidine.