There are many different types of proteins and associated functions. Some more commonly used examples are:
- Enzymes are protein molecules that catalyze biochemical reactions. Common examples are enzymes involved in digestion. Amylase, which breaks down starch into sugars and is present in the saliva of mammals. Pepsin and trypsin are enzymes involved in the protein digestion. Pepsin and trypsin cleaves the large protein molecules into shorter polypeptides which can be passed through the lining of the small intestine.
- Hormones are proteins that are able to transmit signals from one body location to another. Insulin is an extracellular protein and regulates the metabolism of glucose controlling the levels of blood sugar.
- Contractile proteins, like actin and myosin in the muscles, are involved in movement.
- Structural protein are usually filamentous and are used to provide support. Keratin strengthen protective coverings such as hair and nails. Collagen and elastin are important component of the connective tissue, which build tendons and ligaments.
- Transport proteins supply different cellular processes with the required ions, small molecules, or macromolecules, such as another protein. Most common transport proteins are integral membrane proteins they are involved in the transport across a biological membrane.
- Antibodies are another class of protein which are involved in immune response. Their primary function is to bind to foreign for the body substances and thus to identify them for destruction. Antibodies are usually anchored in the membranes of the immune response cells or are excreted into the extracellular matrix.
In general, information encoded in the DNA (the genotype) is expressed by the functions of the proteins and other enzyme-catalyzed products (the phenotype).
Although highly compact, the genetic material in the nucleus (in the form of DNA) is huge and cannot pass through the nuclear membrane, so it must be copied by the smaller, single-stranded RNA (transcription), which moves out of the nucleus to ribosomes located in the cytoplasm and rough endoplasmic reticulum to direct the assembly of protein (translation). The genes do not actually make the protein, but they provide the blueprint in the form of RNA, which directs the protein synthesis.
So at the end, “What Is The Purpose Of Protein Synthesis?”. The cells need Protein Synthesis to produce a variety functional, structural and regulatory units (proteins) that will allow their proper functioning and development.