The Role of Genes in Protein Synthesis
Protein synthesis is the basis for molecular biology and is the name that represents the process which creates proteins within a living organism. Now you might wonder, what do proteins have to do with anything? They are just a substance that bodybuilders drink in order to get stronger. However as unusual as it sounds, proteins are very important within living organisms as they are the compounds which make up the structure of the cell and run biochemical reactions within the cell.
As you can see in the diagram above, proteins like collagen proteins form structures within the cell and proteins like chaperone proteins assist the mitochondria in creating energy. Due to this involvement and everything almost being built by them in a living thing, we can see how proteins are essential in any living organism. When it comes to how proteins look in terms of composition, they are made of amino acids linked together in a chain structure. The amino acids that are part of this chain structure include the following:
By looking at the diagram above, we can observe that there are 20 different types of amino acids with each of them having unique properties. These unique properties are what influence the proteins to do certain things within an organism. When it comes to the protein synthesis and how these proteins are originally created within the body using amino acids all comes down to genes. Genes are mostly codes for proteins and although each cell has the same genetic information as others in a multicellular organism, dependent on its type, it has unique sets of catalysts which express specific portions of the genetic sequence, meaning every type of cell creates a specific set of proteins:
The synthesising of proteins overall is a complex process that can be split into two sections which are known as transcription and translation. Both of these two sections together are known as gene expression. Transcription is the first step and it involves decoding the cell’s genetic information. During this phase of transcription, enzymes known as helices split the DNA double helix structure down the middle by breaking the bonds between the nitrogen bases. After this process of splitting the DNA double helix structure is done, the enzyme known as RNA polymerase starts to create a mRNA strand. In protein synthesis, mRNA acts as a recipe for creating proteins as each amino acid within the protein structure is represented by a unique three nucleotide codon and mRNA contains sequences of these codons. For example, the 3 nucleotide codon of AGC represents the amino acid serine. The enzyme creates the mRNA strand accurately by using the template already presented by the DNA when cut in half with the addition of the complementary base pairing rule. In terms of the complementary base pairing rule, it is essentially a rule that states that adenine can only combine with thymine or uracil(For RNA strands) and that guanine can only combine with cytosine. So for instance if a DNA strand when split into two has one side that consists of AGGTACCAGGTCAAAG, the complementary RNA strand will be UCCAUGGUCCAGUUUC.
After the transcription phase is complete, the mRNA strand leaves the nucleus and finds a ribosome(an organelle which creates proteins using mRNA) beginning the process of translation. The subunits of the ribosome assemble together like a sandwich on the strand of mRNA and starts to pull the mRNA strand in. Later, this leads to the attraction of tRNA molecules. tRNA is known as transfer RNA and it is responsible for carrying amino acids needed for building a protein to the ribosome. Each tRNA molecule has two distinct ends with one being there for binding to an amino acid and the other being there for binding to a corresponding codon on the mRNA strand. When translation is going on, the tRNAs automatically carry the amino acids respective to the codons presented on the mRNA to the ribosomes. With this, the ribosome rRNA(these are the molecules that form the core of all ribosomes and are known as ribosomal RNA) binds the amino acids as they come in according to their sequence. Overall this results in a huge chain of amino acids which can now either fold into a simple protein or can combine with another chain in order to build the structure for a more complex protein.
