Define simple and conjugated protein. Provide some examples of conjugated proteins.

Simple proteins are proteins that are made up of only amino acids. They do not contain any other chemical group. Examples of simple proteins include albumins, globulins, and histones.

On the other hand, conjugated proteins are proteins that are combined with a non-protein molecule, known as a prosthetic group. The prosthetic group can be a metal, a carbohydrate, a lipid, or a nucleic acid. The protein part of a conjugated protein is known as the apoprotein, while the non-protein part is known as the prosthetic group. The prosthetic group can be covalently or non-covalently attached to the protein.

Examples of conjugated proteins include:

1. Glycoproteins: These are proteins that are conjugated with carbohydrates. An example is immunoglobulins, which are antibodies that play a crucial role in the immune response.

2. Lipoproteins: These are proteins that are conjugated with lipids. They play a crucial role in the transport of lipids in the blood. An example is low-density lipoprotein (LDL), which transports cholesterol from the liver to the tissues.

3. Metalloproteins: These are proteins that are conjugated with a metal ion. An example is hemoglobin, which contains iron ions and is responsible for the transport of oxygen in the blood.

4. Nucleoproteins: These are proteins that are conjugated with nucleic acids. They are involved in the storage and transmission of genetic information. An example is chromatin, which is a complex of DNA and protein found in the nucleus of a cell.