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The glycocalyx (pl.: glycocalyces or glycocalyxes), also known as the pericellular matrix and cell coat, is a layer of glycoproteins and glycolipids which surround the cell membranes of bacteria, epithelial cells, and other cells. [1] Animal epithelial cells have a fuzz-like coating on the external surface of their plasma membranes.
The last eukaryotic common ancestor (LECA) is the hypothetical last common ancestor of all living eukaryotes, around 2 billion years ago, [3] [4] and was most likely a biological population. [8] It is believed to have been a protist with a nucleus, at least one centriole and cilium , facultatively aerobic mitochondria, sex ( meiosis and syngamy ...
The eukaryotic signature proteins have no homology to proteins in other domains of life, but appear to be universal among eukaryotes. They include the proteins of the cytoskeleton, the complex transcription machinery, the membrane-sorting systems, the nuclear pore , and some enzymes in the biochemical pathways.
Organelles are parts of the cell that are adapted and/or specialized for carrying out one or more vital functions, analogous to the organs of the human body (such as the heart, lung, and kidney, with each organ performing a different function). [2] Both eukaryotic and prokaryotic cells have organelles, but prokaryotic organelles are generally ...
In 1903, Nikolai K. Koltsov proposed that the shape of cells was determined by a network of tubules that he termed the cytoskeleton. The concept of a protein mosaic that dynamically coordinated cytoplasmic biochemistry was proposed by Rudolph Peters in 1929 [12] while the term (cytosquelette, in French) was first introduced by French embryologist Paul Wintrebert in 1931.
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.
The evolution of eukaryotes, and possibly sex, is thought to be related to the GOE, as it probably pressured two or three lineages of prokaryotes (including an aerobe one, which later became mitochondria) to depend on each other, leading to endosymbiosis. Early eukaryotes lost their cell walls and outer membranes.
The Golgi apparatus (/ ˈ ɡ ɒ l dʒ i /), also known as the Golgi complex, Golgi body, or simply the Golgi, is an organelle found in most eukaryotic cells. [1] Part of the endomembrane system in the cytoplasm, it packages proteins into membrane-bound vesicles inside the cell before the vesicles are sent to their destination.