Virulence factors are part of an important concept in bacterial pathogenicity (Henderson, Poole & Wilson, 1996). According to Cross (2008), Dubey and Maheshwari (2013), virulence factors enable the bacteria to produce a variety of molecules in order to adhere, invade and evade host defences and cause tissue damage. these molecules have been grouped into adhesins, invasins, impedins, aggressins and modulins (Dubey & Maheshwari, 2013: Henderson, Poole & Wilson, 1996).
Bacterial transformation is important because it allows for the cloning and movement of DNA between strains. This transformation usually occurs within plasmids, which are closed circular molecules made up of double stranded DNA. The function of the plasmid is to provide bacteria with genetic advantages such as antibiotic resistance. In this lab, the plasmids provided the ampicillin resistance and the fluorescence. If the bacterial cells are grown in the presence of the antibiotic ampicillin then only the cells that took up the plasmid have the resistance gene.
Chemical transformation, electroporation or particle bombardment is the typical method of construct into a host cell. Conjugation: The easiest illustration is to consider this as a version of bacterial sex. In conjugation the two bacterial cells connect, and the male donates a piece of DNA to the female. The piece of DNA was excised from a bacterial chromosome. The pieces are called plasmids.
Transfection: One of the methods of gene transfer where the genetic material is deliberately introduced into the animal cell in view of studying various functions of proteins and the gene. This mode of gene transfer involves creation of pores on the cell membrane enabling the cell to receive the foreign genetic material. Transfection can be carried out using calcium phosphate (i.e. tricalcium phosphate), by electroporation, by cell squeezing or by mixing a cationic lipid with the material to produce liposomes which fuse with the cell membrane and deposit their cargo inside. The choice of methods of DNA transfer depends upon the target cells in which transformation will be performed. It also depends upon the objectives of gene manipulation.
Tryptophan is an essential amino acid, which is either synthesized or injested from the environment in bacterial cells. The production of tryptophan is an energy consuming process. So bacteria need to ensure that only when the concentration of tryptophan is low inside cell , it has to produce tryptophan. The trp operon is a repressible system that regulates the biosynthesis of tryptophan. The gene for the repressor is located not near to the promoter,but in a different location.
It is believed that an endosymbiotic event occurred where an organism capable of oxidative phosphorylation was consumed by another cell. This theory is backed up by the DNA, double membrane and mitochondrial specific transcription and translation mechanisms used to allow such a phenomenon to occur. Mitochondria still secure their characteristic double membrane structure and are still the primary source of ATP production, from their ancestors. Yet, their overall form has been altered, they have acquired innumerable new functions within the cell.
Mechanism of meiotic recombination The Meiotic recombination is an integral part of the meiotic division in most eukaryotes. It can lead to either crossovers (reciprocal exchange of genetic material between homologous chromosomes), or non-crossovers (non-reciprocal exchange of the genetic material). In eukaryotes, only a small percentage of meiotic DSBs result in crossover products (Sung et al., 2003; Youds and Boulton, 2011). In contrast, repair of DSBs in the mitotic cells happen mostly through the non-crossover recombination pathway, via the sister chromatids.
The roles are as follows for the bacterial cells, the structure flagella are the swimming movement of the cell, pili stabilizes the cells during DNA transfer, the capsules are used as protection for the cell when a method of killing or digestion is happening. The cell wall confers rigidity and the shape they have, the plasmic membranes are the barriers and the location for the enzyme systems which produces energy. The ribosomes like animal and plant is the factor for protein synthesis. The other functions like the Chromosomes and the plasmid make up the DNA of the cell. Explain how bacteria cells make energy for cellular processes.
The plasmid needs to be isolated from the bacterial cells and the technique used is called alkaline lysis. This technique plays around with the pH to extract plasmid DNA. The culture is grown in medium containing ampicillin to select E.coli that have ampicillin resistance gene as their selectable marker. The addition of detergent to the cells causes cell lysis. The detergent attaches to the cell membrane and capture the protein and lipids of the cell membrane causing the cell to rupture.
Introduction As we all know, bacteria is a very complex organism and the subject can be very broad. In this essay, the focus will be on bacteria and the bacterial cell structure. Different forms of bacteria, its pros and cons, the cell structure, diseases and resistance will be explained and listed. First bacteria and cell structure is explained, and then moving on to different bacterial forms and diseases, and how diseases can be prevented or even cured. Then finishing the essay will be the conclusion.
Tn 4351 was originally isolated from bacteroides fragilis  . The transposon was successfully introduced into Cytophaga succinicans, Flavobacterium meningosepticum, Flexibacter canadiansis, Flexibacter strain SFI and Sporocytophaga myxococcoides by conjugation . Tn 4351carries two antibiotic resistance gene. One of the codes for resistance to erythromycin and clindamycin which is expressed in bactroides but not in E.Coli. The other gene codes for resistance in tetracycline and is expressed in aerobically grpwn E. coli, but not in anaerobically grpwn E. coli or in bacteroides.
Introduction: Transforming a gene or genetic information from one organism into another with the hopes that if done successfully the organism with the new DNA will be given new traits is a method known as genetic transformation (Rafter). Genetic transformation is used quite frequently in today’s world, form medicine to agriculture. In this lab we will be inserting a gene into an Escherichia coli bacteria with the help of a plasmid. Escherichia coli bacteria also known as E. coli, is a bacterium that is rod shaped and contains flagella to help it move.
Tubulin is a round protein which is incorporated up with long strings called microtubules. Microtubules shape the axle mechanical assembly used to particular chromosomes amid atomic division. Microtubules are found in plant and creature
Selective medium involves medium with environmental conditions that specifically grows some microbes while inhibiting others. Differential medium is used to identify and differentiate (as the title says) closely related microbes based on growth responses and physical indicators. It is imperative to use laboratory positive and negative controls in identifying the unknown because it confirms and compares the results of the unknown’s response to the definite guide. While performing the procedures in this report, students had to keep the bacterial and biological species concepts in context. The bacterial species concept is the identification and naming of microbes based on relating physical and physiological features of the unknown to the fitting taxa.
It also helps to anchor appendages like the pili and flagella; the wall gives the cell its shape and surrounds the cytoplasm membrane, protecting it from the environment. Cell wall of Vibrio cholera protects the cell osmotic shock and physical damage. In addition, it also confers rigidity and shape of bacterial cells. Capsule Some species of bacteria have a third protective covering.