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The name "homologous series" is also often used for any collection of compounds that have similar structures or include the same functional group, such as the general alkanes (straight and branched), the alkenes (olefins), the carbohydrates, etc. However, if the members cannot be arranged in a linear order by a single parameter, the collection ...
A homologous series is a group of compounds that differ by a constant unit, generally a methylene (−CH 2 −) group. The reactants undergo a homologation when the number of a repeated structural unit in the molecules is increased. The most common homologation reactions increase the number of methylene (−CH 2 −) units in saturated chain ...
More complex alkenes may be named with the E–Z notation for molecules with three or four different substituents (side groups). For example, of the isomers of butene , the two methyl groups of ( Z )-but-2 -ene (a.k.a. cis -2-butene) appear on the same side of the double bond, and in ( E )-but-2-ene (a.k.a. trans -2-butene) the methyl groups ...
The cell cycle is a series of complex, ordered, sequential events that control how a single cell divides into two cells, and involves several different phases. The phases include the G1 and G2 phases, DNA replication or S phase, and the actual process of cell division, mitosis or M phase. [ 1 ]
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.
Alkyl groups form homologous series. The simplest series have the general formula −C n H 2n+1. Alkyls include methyl, (−CH 3), ethyl (−C 2 H 5), propyl (−C 3 H 7), butyl (−C 4 H 9), pentyl (−C 5 H 11), and so on. Alkyl groups that contain one ring have the formula −C n H 2n−1, e.g. cyclopropyl and cyclohexyl.
Extrinsic regulation is made by signals from the niche, where stem cells are found, which is able to promote quiescent state and cell cycle activation in somatic stem cells. [63] Asymmetric division is characteristic of somatic stem cells, maintaining the reservoir of stem cells in the tissue and production of specialized cells of the same.
In eukaryotes, the cell cycle consists of four main stages: G 1, during which a cell is metabolically active and continuously grows; S phase, during which DNA replication takes place; G 2, during which cell growth continues and the cell synthesizes various proteins in preparation for division; and the M phase, during which the duplicated ...