Proteins are the workhorses of the cell, performing many vital functions. They are also the target of a great deal of research, as scientists seek to understand how they work and why they sometimes go wrong.

Proteins are complex molecules made up of amino acids. There are 20 different amino acids, which are strung together like beads on a necklace to form a protein. The order of the amino acids determines the protein’s function.

Proteins are involved in just about every process in the cell, from providing structure to cells to carrying out chemical reactions. They can also be found outside of cells, in the blood and other body fluids.

Proteins are constantly being made and broken down in the cell. When a protein is no longer needed, it is usually broken down into its component amino acids and recycled.

Sometimes, however, proteins don’t function properly. This can be due to a mutation, or change, in the DNA sequence that codes for the protein. These changes can alter the protein’s structure and function.

Mutations in proteins can lead to diseases. For example, sickle cell anemia is caused by a mutation in the protein hemoglobin. Hemoglobin is a protein in red blood cells that carries oxygen around the body.

In sickle cell anemia, the hemoglobin protein is abnormal. This causes the red blood cells to become misshapen and to break down prematurely. As a result, there are not enough healthy red blood cells to carry oxygen around the body, leading to fatigue, pain, and other symptoms.

There are many other diseases that are caused by faulty proteins. Some of these are listed below:

Alzheimer’s disease: A protein called amyloid beta forms clumps in the brain, leading to the death of brain cells.

Celiac disease: An immune reaction to a protein called gluten, found in wheat, barley, and rye, damages the lining of the intestine.

Cystic fibrosis: A protein called CFTR is defective, causing mucus to build up in the lungs and digestive tract.

Duchenne muscular dystrophy: A protein called dystrophin is missing or defective, leading to muscle weakness and wasting.

Hemophilia: A protein called factor VIII is missing or defective, causing problems with blood clotting.

Huntington’s disease: A protein called huntingtin is abnormal, leading to the death of brain cells.

Parkinson’s disease: A protein called alpha-synuclein forms clumps in the brain, leading to the death of brain cells.

Researchers are working to develop treatments for these and other diseases caused by faulty proteins.