Question
Question: List four functions of proteins and name one protein that perform each function....
List four functions of proteins and name one protein that perform each function.
Solution
Proteins are large, complex molecules in the body that play a lot of critical roles. They do most of the cellular work and are important for the structure , function, and control of the tissues and organs of the body.
Complete Answer:
Proteins consist of hundreds or thousands of smaller units called amino acids that are bound in long chains to one another. To produce a protein, there are 20 different forms of amino acids that can be mixed. The amino acid sequence specifies the distinctive 3-dimensional structure of each protein and its particular function.
It is possible to classify proteins according to their wide range of body functions,
| Function | Description | Example |
|---|---|---|
| Antibody | To help protect the body, antibodies bind to specific foreign particles, such as viruses and bacteria. | Immunoglobulin G(IgG) |
| Enzyme | Nearly all of the thousands of chemical reactions that take place in cells are carried out by enzymes. By reading the genetic information contained in DNA, they also assist with the creation of new molecules. | Phenylalanine hydroxylase |
| Messenger | Messenger proteins, such as certain hormone types, transmit signals between various cells, tissues , and organs to organise biological processes. | Growth hormone |
| Structural component | For cells, these proteins provide structure and support. They also encourage the body to move on a larger scale. | Actin |
| Transport/ storage | Within cells and throughout the body, these proteins bind and hold atoms and tiny molecules. | Ferritin |
Amino acids are categorised as essential or non-essential, respectively. As the name suggests, the body does not produce essential amino acids, so they must come from our diet. Non-essential amino acids, however, can be produced by the body and therefore do not have to come from the diet.
Note: Proteins are structured into four levels: major, secondary, tertiary, and quaternary (optional). The special sequence of amino acids is the primary structure. The secondary structure is the local folding of the polypeptide to form structures such as the x-a helix and β-pleated sheet. The tertiary structure is the overall three-dimensional structure. The arrangement is known as the quaternary structure of a protein, when two or more polypeptides combine to form the complete protein structure.