Search results
Results from the WOW.Com Content Network
A cell wall is a structural layer that surrounds some cell types, found immediately outside the cell membrane.It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier. [1]
Structure of a plant cell. Plant cells are the cells present in green plants, photosynthetic eukaryotes of the kingdom Plantae.Their distinctive features include primary cell walls containing cellulose, hemicelluloses and pectin, the presence of plastids with the capability to perform photosynthesis and store starch, a large vacuole that regulates turgor pressure, the absence of flagella or ...
The number of mitochondria in a cell can vary widely by organism, tissue, and cell type. A mature red blood cell has no mitochondria, [19] whereas a liver cell can have more than 2000. [20] [21] The mitochondrion is composed of compartments that carry out specialized functions.
Plant cells, similar to animal cells, respond to externally applied forces, such as by reorganization of their cytoskeletal network. The presence of a considerably rigid extracellular matrix, the cell wall, however, bestows the plant cells with a set of particular properties. Mainly, the growth of plant cells is controlled by the mechanics and ...
Secondary cell walls provide additional protection to cells and rigidity and strength to the larger plant. These walls are constructed of layered sheaths of cellulose microfibrils, wherein the fibers are in parallel within each layer. The inclusion of lignin makes the secondary cell wall less flexible and less permeable to water than the ...
The eukaryotic cell is thought to have arisen when an ancestral archaeal cell internalized an aerobic bacterium (the proto-mitochondrion). Mans et al. [ 5 ] proposed that the evolutionary development of the eukaryotic cell nucleus was triggered by this archaeo-bacterial symbiosis .
Cell expansion begins with the selective loosening of the cell wall, reducing the plant cell's turgor pressure and water potential. This allows for the influx of water, leading to cell enlargement. [3] This enlargement is made possible by the sliding of polymers, increasing the cell wall's surface area. In most plants, cell expansion is ...
The function and significance of vacuoles varies greatly according to the type of cell in which they are present, having much greater prominence in the cells of plants, fungi and certain protists than those of animals and bacteria. In general, the functions of the vacuole include: Isolating materials that might be harmful or a threat to the cell