Task no. 1: GENERAL PRINCIPLES OF MICROBIOLOGY1. Describe the components of the bacterial cell envelope and the primary function of each. The innermost layer of the bacterial cell envelope is the cell membrane. It is a typical phospholipid bilayer, as found in animal cells. The primary function of the cell membrane is energy production and active transport. The next layer is the cell wall. It is composed of N-acetyl glucosamine and N-acetyl muramic acid. Amino acids hold the cell wall together by forming cross bridges. The primary function of the cell wall is to protect bacteria from their environment. It also acts as an osmotic barrier and provides the bacteria with shape. The outermost layer of the cell envelope is the outer membrane. The outer membrane contains lipopolysaccharides, which act as an endotoxin. However, only gram-negative bacterial cells contain the outer membrane. Furthermore, the periplasmic space is located between the cell membrane and the cell wall. It is filled with periplasm, composed of water and proteins. Proteins act in degradation, transport and motility. (Source: http://www.microbiologytext.com/index.php?module=Book&func=displayarticle&art_id=59)2. A 62-year-old patient was diagnosed with shingles. This is called a latent infection. - Which category of viruses causes latent infections? DNA viruses cause latent infections. Retroviruses, such as HIV, also have the ability to become latent after the enzyme reverse transcriptase creates DNA. There are some bacteria that also cause latent infections. With an example, explain the difference between latent viruses and latent bacterial infections. In latent viruses, such as herpes, the viral genome remains in the host cells, but the infectious virons do not...... middle of paper ..... .red.8. Why is it important from a clinical point of view to know the Gram stain and the morphology of infecting bacteria? Without completing the Gram stain, it is very difficult to see the bacteria. The Gram stain provides some clues that narrow down the type of bacteria it might be. First, the Gram stain result (what color it becomes) helps identify whether it is a gram-negative or gram-positive bacterium. The Gram stain also allows you to see the shape of the bacteria. Both the color characteristics and the shape help define which bacteria you are dealing with. Once this is known, it is much easier to treat. For example, there are very few gram-positive bacteria that infect humans. If this type of bacteria is found, you have a very good idea of ​​what the infection might be and could use one of the antibiotics that work well on this type of bacteria.