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The surface-area-to-volume ratio has physical dimension inverse length (L −1) and is therefore expressed in units of inverse metre (m-1) or its prefixed unit multiples and submultiples. As an example, a cube with sides of length 1 cm will have a surface area of 6 cm 2 and a volume of 1 cm 3. The surface to volume ratio for this cube is thus
In geometry, the Weaire–Phelan structure is a three-dimensional structure representing an idealised foam of equal-sized bubbles, with two different shapes. In 1993, Denis Weaire and Robert Phelan found that this structure was a better solution of the Kelvin problem of tiling space by equal volume cells of minimum surface area than the previous best-known solution, the Kelvin structure.
The increase in the surface area to volume ratio also gives the cell decreased osmotic fragility, as it allows it to take up more water for a given amount of osmotic stress. In vivo (within the blood vessel), the codocyte is a bell-shaped cell. It assumes a "target" configuration only when processed to obtain a blood film.
[8] [9] Microtentacles are cell protrusions attached to free-floating cells, associated with the spread of some cancer cells. [10] In prokaryotes such protrusions are known as surface or cell-surface appendages and include flagella, pili, fimbriae, and nanowires. [11] [8] Some archaea possess very complex appendages known as hami. [12]
Light micrograph of a moss's leaf cells at 400X magnification. The following outline is provided as an overview of and topical guide to cell biology: . Cell biology – A branch of biology that includes study of cells regarding their physiological properties, structure, and function; the organelles they contain; interactions with their environment; and their life cycle, division, and death.
Cytosol makes up about 70% of the cell volume and is a complex mixture of cytoskeleton filaments, dissolved molecules, and water. The cytosol's filaments include the protein filaments such as actin filaments and microtubules that make up the cytoskeleton, as well as soluble proteins and small structures such as ribosomes , proteasomes , and the ...
Indeed, representing a cell as an idealized sphere of radius r, the volume and surface area are, respectively, V = (4/3)πr 3 and SA = 4πr 2. The resulting surface area to volume ratio is therefore 3/r. Thus, if a cell has a radius of 1 μm, the SA:V ratio is 3; whereas if the radius of the cell is instead 10 μm, then the SA:V ratio becomes 0.3.
Thus, microvilli not only increase the cellular surface area for absorption, they also increase the number of digestive enzymes that can be present on the cell surface. Microvilli are also present on immune cells, allowing the immune cells to sense features on the surface of pathogens and other antigen-presenting cells. [4]