Protein Synthesis Lab Report

Introduction to Protein Synthesis

In order to understand the methods in which a macrolide attacks a bacterium, it is important to understand the structure and function of the bacterial mechanism for protein synthesis. A bacterium’s DNA holds the structure of a circular double strand. Like the DNA of any other living organism, it contains the genetic coding for the bacteria. This genetic coding is crucial for the growth, development, and survival of the cell. The bacteria’s DNA contains the proteins required for reproductions, reparations of the cell, and regulations of metabolism. Additionally, DNA codes for the three different kinds of RNA the are needed for the synthesis of proteins. These different types of RNA include messenger

The process of protein synthesis begins with a DNA molecule forming a new mRNA strand. Messenger RNA will provide the encoding of amino acid sequences of a polypeptide. This action begins by separating and unwinding the double stranded DNA in the area that codes for the needed protein. The unwinding and separation of the double stranded DNA is done by the enzyme, helicase. Helicase is able to unwind the double strand of DNA by breaking the hydrogen bonds connecting the complementary nitrogenous bases. Once the DNA is unwinded, only one strand will serve as the template for the process of transcription. Transcription is the process of forming messenger RNA from the bacterial DNA strand. The enzyme RNA polymerase will connect complementary RNA bases to the DNA template strand. These RNA bases are bonded together to form a single stranded mRNA. Therefore this mRNA molecule contains a template based on the DNA. This newly formed mRNA will now detach itself from the DNA strand and search for a ribosomal RNA (rRNA). Ribosomal RNA is the element of RNA found in ribosomes which plays a role in translation. Translation is divided into four different phases: initiation phase, elongation

This type of resistance may be at a high level. This mechanism of resistance is mediated by the erm (Erythromycin Resistance Methylase) gene. This gene is found on plasmids or transposons ie small genetic elements which are capable of moving from one bacterium to another and integrating into the host chromosomal DNA. Copies of the erm gene are transported to other bacteria via plasmids or transposons thru=ogh polite channels. The erm gene is incorporated into the new bacterial genome. During the process of protein synthesis this bacterium will transcribe and translate the genetic coding of the erm gene, resulting in the production of a protein enzyme capable of methylating the 50s ribosomal subunit at a specific position. This alteres 50s subunit results in decreased binding affinity for macrolides and other antibiotics. This pattern of resistance is referred to as the MLS phenotype. Because the macrolide antibiotic is unable to bind to the 50s ribosomal subunit, it is unable to inhibit protein synthesis and this the bacteria itself is not harmed, continuing to produce polypeptide chains of amino