Unit 4222-265 Causes and spread of infection (ICO2) Understand the causes of infection 1. The differences between bacteria, viruses, fungi and parasites Bacteria belong to a group of single celled microorganisms which are classified as prokaryotes i.e. they do not have membrane bound organelles. They have no true nucleus as the DNA is not contained within a membrane or separated from the rest of the cell, but is coiled up in a region of the cytoplasm called the nucleoid and the cell is surrounded by a cell wall an outer covering that protects the bacterial cell and gives it shape. Viruses are infectious agents, often highly host-specific, consisting of genetic material surrounded by a protein coat.
The article “Do Viruses Meet the Conditions to be Called a Life Form” by Jackson Pollock states “To be called "living" the organism must qualify under the seven categories; they must have order, be able to reproduce, be able to grow and develop, utilize energy, respond to their environment, maintain homeostasis, and adapt through evolution. Viruses qualify under all of these categories except metabolism and reproduction, for which they act as a parasite and use a host cell to do it for them.” This shows that viruses do not meet all of the characteristics needed to be considered a living thing. However some might that viruses are living things because according to the the article “Giant Viruses are Ancient Living Organisms” by LiveScience Staff states “For instance, the ocean's largest virus, a giant virus called CroV, has genes that let it repair its genome.” That means that viruses are able to repair their DNA without the help of another cell. On the other there is better evidence to support the claim that viruses are not living because according to the article “HIV: Evolving Menace” by anonymous states “But a virus can’t make copies by itself; it needs the equipment of a living cell.” That shows that since viruses can’t reproduce on their own, they are not a living thing. The article “Do Viruses Meet the Conditions to be Called a Life Form” by Jackson Pollock states “A virus is not alive, but is on the
What is recombinant DNA technology? 6. What are the molecular tools used to assemble recombinant DNA? 7. How can recombinant DNA and bacterial cells be used to produce vaccines?
Changes in climate or introduction of a new species from elsewhere can greatly affect the balance of nature. A virus is a small infectious agent that can replicate only inside the living cells of organisms. Most viruses are too small to be seen directly with a light microscope. Viruses infect all types of organisms, from animals and plants to bacteria and archaea. All viruses have genes made from either DNA or RNA, long molecules that carry genetic information; all have a protein coat that protects these genes; and some have an envelope of fat that surrounds them when they are outside a cell.
Prokaryotic cells are found in organisms such as bacteria, most commonly eubacteria and archae bacteria. Eukaryotic cells are therefore are found in all other living organisms, the name implying that there is a proper nucleus present. As there is no nucleus present in prokaryotic cells the DNA helix is a single coiled chromosome that is unsupported and so can float freely around the cell, however in a eukaryotic cell the DNA helix is made up of linear chromosomes supported by the histone protein. In Eukaryotic cells there is also a distinct nuclear membrane Prokaryotic cells are smaller than Eukaryotic cells, according to “Pharmaceutical Microbiology†the majority of bacteria fall within the general dimensions of 0.75 to 4mm compared to the size of common eukaryotic cells which can be up to 40 times larger than Prokaryotic cells and measure between 50 and 150mm. Prokaryotic cells and Eukaryotic cells both can contain a cell wall however in prokaryotic cells the cell wall is peptidoglycan (a mixture of sugar and protein) if the organism is a eubacteria, or pseudomurein if the organism is a archae bacteria whereas in eukarotic cells a cell wall is only present if the organism is a plant or a fungi and the cell wall is constructed of cellulose in plants or chitin if the organism is a fungi.
But some bacteria can cause diseases, either because they end up in the wrong place in the body or simply because they are 'designed' to invade us. Bacteria can infect humans, plants, or animals VIRUSES - A virus (from the Latin virus meaning toxin or poison) is a small infectious agent, too small to be seen by the naked eye. They can't multiply on their own, only inside the cells of other organisms. They have to invade a 'host' cell and take over its machinery in order to be able to make more virus particles. Viruses consist of genetic materials (DNA or RNA) surrounded by a protective coat of protein.
Prions are neither fungal nor viral and they contain no genetic material, but they have been held responsible for a number of degenerative brain diseases including CJD. The harmless and infectious forms of prion protein are nearly identical making it nearly impossible to tell the difference, but the infectious prion takes a folded shape compared to the normal protein. For many reasons still unknown this prion, when altered, can destroy nervous system tissues like the brain and the spinal cord. Creutzfeldt-Jakob disease and its variants belong to a broad group of human and animal diseases known as transmissible spongiform encephalopathies or TSEs. The name is derived from the spongy holes that are only visible under a microscope that develop in the affected brain tissue.
There are many different reasons of why a zombie outbreak could happen. The first reasons are because of GMO’s. GMO’s are ‘Genetically Modified Organisms’ that meet the specifications of a zombie. They are usually plants and/or animals that have been genetically engineered and implanted with DNA from bacteria, viruses, and other species that could have had a possible case of rabies. Another reason that a zombie outbreak could happen is because of biological warfare.
Changes in climate or introduction of a new species from elsewhere can greatly affect the balance of nature. Viruses: A virus is a small infectious agent that can replicate only inside the living cells of organisms. Most viruses are too small to be seen. Viruses infect all types of organisms, from animals and plants to bacteria . All viruses have genes made from either DNA or RNA, all have a protein coat that protects these genes; and some have an envelope of fat that surrounds them when they are outside a cell.
Gabriella Wright BSc Biomedical Science Y2 Immunology An account of the immune response to parasites Introduction As a host the human body is constantly bombarded by pathogenic invasion. The prime first defence to these invasive antigens is our skins epithelial surface and gut lining. The Innate and adaptive immune system work together to provide the host with a unique defence system, in encountering a wide variety of pathogens. There are four types of pathogen that can invade a host; these are viruses, protozoa, helminths and bacteria. The following essay will give an account of the immune response to bacterial parasites, and then follow with an account of an immune response to Malaria which is a protozoan disease.