Proteins
- [Wisconsin - Forbes]
- Overview
A protein is a naturally occurring, extremely complex substance consisting of amino acid residues linked by peptide bonds. Proteins are present in all living organisms and include many essential biological compounds such as enzymes, hormones and antibodies.
Proteins are large, complex molecules that play many key roles in the body. They do most of the work in cells and are necessary for the structure, function and regulation of human tissues and organs.
Proteins are made up of hundreds or thousands of small units called amino acids, which are connected to each other in long chains. There are 20 different types of amino acids that can be combined into proteins. The amino acid sequence determines the unique 3-dimensional structure of each protein and its specific function. Amino acids are encoded by a combination of three DNA building blocks (nucleotides), determined by the gene sequence.
Proteins can be described according to their broad functions in the body, listed alphabetically:
- Antibodies: Antibodies bind to specific foreign particles, such as viruses and bacteria, to help protect the body. For example, immunoglobulin G (IgG).
- Enzymes: Enzymes complete almost thousands of chemical reactions that take place in cells. They also help form new molecules by reading genetic information stored in DNA. For example, phenylalanine hydroxylase.
- Messenger: Messenger proteins, such as certain types of hormones, transmit signals to coordinate biological processes between different cells, tissues, and organs. For example, growth hormone.
- Structural components: These proteins provide structure and support to cells. On a larger scale, they also allow body movement. For example, actin.
- Transport/Storage: These proteins bind and carry atoms and small molecules within cells and throughout the body. For example, ferritin.
[More to come ...]
