Introduction
Viruses are the most abundant organisms in the sea, with approximately ten billion in every litre of sea water(1, 2). Viruses are very small at generally 20-200nm, and have a simple structure consisting of genetic material with a protein coat, and sometimes a lipid envelope(2). Due to their simplicity, viruses rely on exploiting living cells and using the host’s cellular machinery to replicate(3). Irrespective of their size, viruses have been found to have a significant influence on many ecological processes and biogeochemical cycles in marine ecosystems(2, 4). Studies suggest that viruses contribute to nutrient recycling through the infection and lysis of marine microorganisms, which in turn controls the composition and diversity of microbial communities in marine environments(1, 5). Genes involved in photosynthesis have also been found in viral genomes, leading researchers to believe that proteins involved in bacterial photosynthesis originate from bacteriophages, viruses which infect the bacteria(6, 7). Research on marine viruses is important because it allows us to gain a deeper understanding of ocean ecology and the driving forces behind marine and global ecosystems(8).
Discussion
Every second, approximately 1023 viral infections occur in the ocean(8). These infections affect the mortality of marine organisms and are subsequently a major force behind global geochemical cycles and the structure of microbial populations and communities(4, 5, 8). Microorganisms constitute 90% of the living biomass in the sea, and it is estimated that 20% of this biomass is eliminated by viruses every day(8).Viruses influence the mortality of bacteria in the ocean and therefore regulate both bacterial populations and those in subseq...
... middle of paper ...
...olonen AC, Rohwer F, Chisholm SW. 2004. Transfer of photosynthesis genes to and from Prochlorococcus viruses. Proceedings of the National Academy of Sciences of the United States of America 101:11013-11018.
17. Lindell D, Jaffe JD, Johnson ZI, Church GM, Chisholm SW. 2005. Photosynthesis genes in marine viruses yield proteins during host infection. Nature 438:86-89.
18. Mann NH, Clokie MR, Millard A, Cook A, Wilson WH, Wheatley PJ, Letarov A, Krisch HM. 2005. The genome of S-PM2, a "photosynthetic" T4-type bacteriophage that infects marine Synechococcus strains. Journal of bacteriology 187:3188-3200.
19. Brussaard CPD, Wilhelm SW, Thingstad F, Weinbauer MG, Bratbak G, Heldal M, Kimmance SA, Middelboe M, Nagasaki K, Paul JH, Schroeder DC, Suttle CA, Vaque D, Wommack KE. 2008. Global-scale processes with a nanoscale drive: the role of marine viruses. ISME J 2:575-578.
The majority of life on Earth depends on photosynthesis for food and oxygen. Photosynthesis is the conversion of carbon dioxide and water into carbohydrates and oxygen using the sun’s light energy (Campbell, 1996). This process consists of two parts the light reactions and the Calvin cycle (Campbell, 1996). During the light reactions is when the sun’s energy is converted into ATP and NADPH, which is chemical energy (Campbell, 1996). This process occurs in the chloroplasts of plants cell. Within the chloroplasts are multiple photosynthetic pigments that absorb light from the sun (Campbell, 1996).
Todar, K. (2002). Streptococcus pyogenes (Vol. 1). Madison: University of Wisconsin-Madison Department of Bact. Retrieved July 30, 2008, from http://www.textbookofbacteriology.net/streptococcus.html
Viruses have been long considered to be a living organism. They have their own DNA which makes it a debatable issue of whether or not to categorize them as living. They require energy to replicate/ survive within a host cell and so they take control of various organelles including mitochondria. [1]
Orthopoxvirus variola is the virus responsible for the well-known smallpox disease. It belongs to the Poxviridae family which is further split into the subfamilies Entomopoxivirinae which only affects insects, and Chordopoxivirinae which infects vertebrae (Hughes). It is in group one of the Baltimore Classification since it possesses double-stranded DNA. This group also includes viruses in the Herpesviridae family, certain bacteriophages, as well as the mimivirus. The linear genome consists of approximately 186 kb pair and, like all orthopoxviruses, is about 200 nm in diameter (Li; Riedel). Virus particles may be enveloped, but the majority will be nonenveloped when released from a lysed cell, ready and capable to affect another. Extracellular enveloped viruses evolve from their precursors intracellular enveloped virus and cell-associated enveloped virus and contain proteins that aid the virus in neutralizing host cell antibodies to enhance virus spread (Smith). Entrance into the host cell may be accomplished by fusion of endocytosis, contingent on the particular strain. Host cell cytoplasm is the site of poxvirus replication, therefore host nuclear enzymes are unavailable to the virus; to overcome this, DNA-dependent RNA polymerase enters the host with the virus (Hughes).
consists of a polyhedral head and a tail. The tail is used to inject DNA into a
It is obvious that the sharks and rays of the ocean have existed for a tremendous length of time, 450 million years to be exact. They have survived without dying from bacterial infections, diseases or viruses. This may be because their immune system has changed minutely over those 450 million years. It seems that cartilaginous fish have four different classes of immunoglobulin and that shark antibodies lack the specificity that permits recognition of the subtle differences between two similar types of bacteria (Litman, 68). Sharks antibodies lack the capacity to bind more strongly to an antigen during the course of a prolonged immune response, which has been determined to be an advantage in fighting infection (Litman, 68). Some would think that this inhibits the shark from being able to fight off anything. However, this ancient immune system benefits the shark wholeheartedl...
Viruses are the simplest and tiniest of microbes, and are made up of proteins, nucleic acid, and lipids. The nucleic acids contain the genetic code that helps them grow and reproduce, but only once they find their way into a living organism. Viruses themselves are not considered living organisms because they don’t have cells, they don’t metabolize nutrients, produce and excrete wastes, and they can’t move around on their own. The remains of the nucleic acid then forms a covering, called the capsid. Once the capsid gets removed, viruses use the building materials of th...
Despite its importance as an infectious agent, relatively little is known about T. pallidum in comparison with other bacteria. The genome of Treponema pa...
Tettelin, H., Nelson, K. E., Paulsen, I. T., Eisen, J. A., Read, T. D., Peterson, S., et al. (2001). Complete genome sequence of a virulent isolate of Streptococcus pneumoniae. Science. Retrieved from http://www.sciencemag.org/content/293/5529/498.short (Accessed December 12, 2013).
Dinoflagellates are one of the four main types of phytoplankton, which are photosynthetic, single celled and free living organisms in the ocean. Dinoflagellates cause the Harmful Algal Blooms (HAB) also known as the red tide effect (Hackett et al 2004). Toxicity persisting at upper levels of the food chain is detected in them from the ones which are toxic, but not all such blooms are toxic. Enhanced detection capabilities may in part contribute to observed high frequency and severity of toxic blooms. As they are also important in the health of coral reefs their study has gained significant interest. Species are often selected for genome sequencing based on their importance as a model organism or relevance to human health, such as the HAB case.
“Photosynthesis (literally, “synthesis from light”) is a metabolic process by which the energy of sunlight is captured and used to convert carbon dioxide (CO2) and water (H2O) into carbohydrates (which is represented as a six-carbon sugar, C6H12O6) and oxygen gas (O2)” (BioPortal, n.d., p. 190).
Microbes are everywhere in the biosphere, and their presence invariably affects the environment in which they grow. The effects
The energy extracted today by the burning of coal and petroleum products represents sunlight energy captured and stored by photosynthesis almost 200 million years ago. A third very interesting group of bacteria synthesize sugars, not by using sunlight’s energy, but by extracting energy from inorganic chemical compounds; In a (d) deep sea vent, chemoautotrophs, such as these (e) thermophilic bacteria, capture energy from inorganic compounds to produce organic compounds.
These results agree with the hypothesis that our “untouched and super-productive world” is affecting marine life ecosystems (Vannela, 2012). All of these results combined confirm the overall hypothesis that pollution is getting worse in the ocean and more marine life ecosystems are being affected, but there