A hemoglobin molecule is composed of:
(a) Two protein chains
(b) Three protein chains
(c) Four protein chains and nothing else
(d) Four protein chains and four heme groups
(e) Four heme groups but no protein

Verified step by step guidance

1. Recall the basic structure of a hemoglobin molecule, which is a protein responsible for oxygen transport in the blood.
2. Understand that hemoglobin is a quaternary protein, meaning it is made up of multiple polypeptide chains.
3. Identify that hemoglobin consists of four protein chains, typically two alpha and two beta chains.
4. Recognize that each of these protein chains is associated with a heme group, which contains an iron ion capable of binding oxygen.
5. Conclude that the complete hemoglobin molecule is composed of four protein chains and four heme groups.

Key Concepts

Structure of Hemoglobin

Hemoglobin is a complex protein found in red blood cells responsible for oxygen transport. It consists of multiple polypeptide chains, which form its quaternary structure, allowing it to bind oxygen efficiently.

Protein Chains in Hemoglobin

Hemoglobin is made up of four protein chains, typically two alpha and two beta globin chains. These chains create a stable framework that supports the binding of heme groups and oxygen molecules.

Heme Groups in Hemoglobin

Each protein chain in hemoglobin is associated with a heme group, which contains an iron ion capable of binding oxygen. The four heme groups enable hemoglobin to carry up to four oxygen molecules simultaneously.