As mentioned in the previous two pages investigating protein synthesis, each consists of a successive chain of amino acids. The sequence of these amino acids determine which type of protein it is. It is synthesised from a DNA strand, each DNA strand involved in protein synthesis is responsible for producing a unique protein.
Types of Protein
Over time and diversity of organisms, a huge amount of proteins exist and perform a unique function in the body. Primarily, their are three types of protein
- Fibrous Proteins - These fibre like proteins are used for structural purposes in organisms. This is because fibrous proteins are arranged in long strands and are insoluble in water. Examples of use include providing a barrier in the cell wall of plants and myosin in skeletal muscle
- Globular Proteins - The polypeptide chains (protein chains) in globular proteins are folded together into a knot like shape essential in the fact that are present in the following
1. Enzymes - Biological catalysts, enzymes are responsible speeding up reactions in an organism
2. Hormones - Hormones are chemical messengers responsible for initialising a response in organisms. Some hormones have a regulatory effect, explained in later chapters in the tutorial
3. Antibodies - Antibodies are used to defend the body against foreign agents e.g. bacteria, fungi and viruses. The next page investigates these.
4. Structural Protein - Globular proteins form part of the cell membrane, which has a structural role as well as a role in transporting ions in and out the cell.
- Conjugated Proteins - Conjugated proteins are essentially globular proteins that possess non-living substances, such as the haem found in haemoglobin, which possesses iron (a non-living substance)
Therefore proteins play a vital role in many of an organisms biological processes and their organs. The following page investigates cell defense against foreign agents, where proteins are playing their role in the form of antibodies...