The virus genome covered by the capsid penetrates the host cell. Once inside, the virus is uncoated as the envelope and capsid are removed. Free of its covering, the viral genome (DNA or RNA) proceeds with biosynthesis. Newly assembled viral particles are released by budding. Components of viral envelopes (i.e., lipids, proteins, and carbohydrates) are obtained from the plasma or nuclear membrane as the viruses leave the cell. Budding does not necessarily kill the host cell.
A retrovirus is a virus which has a genome consisting of two plus sense RNA molecules, which may or may not be identical. It relies on reverse transcriptase to perform the reverse transcription of its genome from RNA into DNA, which can then be integrated into the host's genome with an integrase. The virus itself is a storage form for its nucleic acid genome as well as a means of delivery of its genome into targeted cells, which constitute the infection. Once in the host's cell, the RNA strands undergo reverse transcription in the cytosol. Once integrated into the host's genome, the retroviral DNA, is then referred to as a provirus.
While transcription was classically thought to only occur from DNA to RNA, reverse transcriptase transcribes RNA into DNA. The term "retro" in retrovirus refers to this reversal of the central dogma of molecular biology. Reverse transcriptase activity outside of retroviruses has been found in almost all eukaryotes, enabling the generation and insertion of new copies of retrotransposons into the host genome.
Because reverse transcription is missing the usual "proofreading" of DNA transcription, this kind of virus mutates very often. This enables the virus to quickly grow resistant to antiviral pharmaceuticals, and is one of...
Bacteria? Many people believe that bacteria only cause disease and death. This is not technically true. While we have all suffered from some kind of an infection which we are told is caused some noxious form of bacteria, this is just a small part of what bacteria contribute to out lives. First, it would be well to add a bit of science to be clear about what bacteria are. Defined most
What are Bacteria and Viruses? The most palpable variance between bacteria and viruses is their size. Whereas both bacteria and viruses are too tiny to notice with the naked eye, most bacteria are about one micrometer in length and can be perceived with a good optical microscope. On the other hand, viruses are smaller than the wavelength of visible light, which implies that they can be solely perceived by using an
Bacteria Effect of date extract on different types of bacteria Taxonomy of date Kingdom: Plantae Division: Magnoliophyta Liliopsida Order: Arecales Family: Arecaceae Genus: Phoenix Species: Phoenix dactylifera Binomial mane: Phoenix dactylifera Linn (Bostoen 2005) Botanical Descriptions The date palm is known in technical terms by its botanical name Phoenix dactylifera. The properties and the composition of the date extract have been noted to have many beneficial effects in medicine as well as domestically. The following paper intends to shed light on the impact
human papilloma virus and the description of epidemiology as it relates to the virus. Steps and methods of epidemiology have been discussed in detail alongside statistical data for demographics taken from surveillance records. Moreover, research data have been taken as vital assistance to compliment the study of this research paper and to prove results with evidences from researches (Duncan, 1988). Statistics have been taken from World Health Organization for the
Gram Stain Bacteria Identification Following standard procedure for Gram staining, a slide was prepared by heat fixing the sample and applying the primary crystal violet stain (Bruckner, 2012). After incubation in the primary stain for a period of one minute, the stain was rinsed under a slow stream of water for four seconds before fixing the remaining dye with Gram's iodine, with immersion in this mordant lasting one minute (Bruckner, 2012). Following
HIV Human Immunodeficiency Virus (HIV) is a virus that attacks the immune system causing the individual to be at risk for opportunity infections, or infections that come about because the immune system is weak. It is a slow progressive disease that is present throughout the body. Humans can get infected with HIV through contact with tissues, such as vaginal, anal area, mouth, eyes, or a break in the skin, such
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