Search results
Results from the WOW.Com Content Network
Cell structure of a gram positive bacterium. In comparison to eukaryotes, the intracellular features of the bacterial cell are extremely simple. Bacteria do not contain organelles in the same sense as eukaryotes. Instead, the chromosome and perhaps ribosomes are the only easily observable intracellular structures found in all bacteria. There do ...
Structural model at atomic resolution of bacteriophage T4 [1] The structure of a typical myovirus bacteriophage Anatomy and infection cycle of bacteriophage T4.. A bacteriophage (/ b æ k ˈ t ɪər i oʊ f eɪ dʒ /), also known informally as a phage (/ ˈ f eɪ dʒ /), is a virus that infects and replicates within bacteria and archaea.
The body's cells constantly display short fragments of their proteins on the cell's surface, and, if a T cell recognises a suspicious viral fragment there, the host cell is destroyed by 'killer T' cells and the virus-specific T-cells proliferate. Cells such as the macrophage are specialists at this antigen presentation. [156]
Replication follows the ssDNA rolling circle model. DNA-templated transcription is the method of transcription. The virus exits the host cell by viral extrusion. [23] Viral assembly occurs at the inner membrane (in case of Gram-negative bacteria), mediated by a membrane-embedded motor protein complex. [23]
Spiral bacteria are another major bacterial cell morphology. [2] [30] [31] [32] Spiral bacteria can be sub-classified as spirilla, spirochetes, or vibrios based on the number of twists per cell, cell thickness, cell flexibility, and motility. [33] Bacteria are known to evolve specific traits to survive in their ideal environment. [34]
The virus then releases its genetic material (either single- or double-stranded RNA or DNA) into the cell. In some viruses this genetic material is circular and mimics a bacterial plasmid. At this stage the cell becomes infected and can also be targeted by the immune system. It is mostly aided by receptors on the surface of the cell.
6. After the host cell has divided, the phage DNA in the daughter cells activate, and the phage DNA begins to express itself. Some of the cells containing the prophage go on to create new phages which will move on to infect other cells. Lysogeny, or the lysogenic cycle, is one of two cycles of viral reproduction (the lytic cycle being
When the bacterial DNA packaged into the virus is inserted into the recipient cell three things can happen to it: [citation needed] [5] The DNA is recycled for spare parts. If the DNA was originally a plasmid, it will re-circularize inside the new cell and become a plasmid again. If the new DNA matches with a homologous region of the recipient ...