Search results
Results From The WOW.Com Content Network
The prokaryotic cell is shown with its DNA, in green. 2. The bacteriophage attaches and releases its DNA, shown in red, into the prokaryotic cell. 3. The phage DNA then moves through the cell to the host's DNA. 4. The phage DNA integrates itself into the host cell's DNA, creating prophage. 5. The prophage then remains dormant until the host ...
The least sensitive are nerve cells and muscle fibers. Very sensitive cells are also oocytes and lymphocytes, although they are resting cells and do not meet the criteria described above. The reasons for their sensitivity are not clear. There also appears to be a genetic basis for the varied vulnerability of cells to ionizing radiation. [4]
The eukaryotic cell cycle consists of four distinct phases: G 1 phase, S phase (synthesis), G 2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm and cell membrane divides forming two daughter cells.
Recent research has proposed the idea that HeLa cells damaged with radiation (cells that are unique in that they have short-shouldered survival curves and two peaks of radio resistance during the cell cycle phase) show the fact that radio-suppression is mediated by intra-s checkpoints and reduces survival of cells in the s-phase.
Due to its ability to induce cell cycle arrest, ionizing radiation is used on abnormal growths in the human body such as cancer cells, in radiation therapy. Most cancer cells are fully treated with some type of radiotherapy, however some cells such as stem cell cancer cells show a reoccurrence when treated by this type of therapy. [1]
The cell cycle is driven by proteins called cyclin dependent kinases that associate with cyclin regulatory proteins at different checkpoints of the cell cycle. Different phases of the cell cycle experience activation and/or deactivation of specific cyclin-CDK complexes. CyclinB-CDK1 activity is specific to the G2/M checkpoint.
Entry, or penetration, is the second step in viral replication. This step is characterized by the virus passing through the plasma membrane of the host cell. The most common way a virus gains entry to the host cell is by receptor-mediated endocytosis, which comes at no energy cost to the virus, only the host cell. Receptor-mediated endocytosis ...
Radiation used for cancer treatment is called ionizing radiation because it forms ions in the cells of the tissues it passes through as it dislodges electrons from atoms. This can kill cells or change genes so the cells cannot grow. Other forms of radiation such as radio waves, microwaves, and light waves are called non-ionizing.