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In music theory, a tetrachord (Greek: τετράχορδoν; Latin: tetrachordum) is a series of four notes separated by three intervals.In traditional music theory, a tetrachord always spanned the interval of a perfect fourth, a 4:3 frequency proportion (approx. 498 cents)—but in modern use it means any four-note segment of a scale or tone row, not necessarily related to a particular tuning ...
Many eukaryotic cells contain large ribonucleoprotein particles in the cytoplasm known as vaults. [3] The vault complex comprises the major vault protein (), two minor vault proteins (VPARP and TEP1), and a variety of small untranslated RNA molecules known as vault RNAs (vRNAs, vtRNAs) only found in higher eukaryotes.
Embedded within this membrane is a macromolecular structure called the porosome the universal secretory portal in cells and a variety of protein molecules that act as channels and pumps that move different molecules into and out of the cell. [2]
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.
The first type is a circular genome that has introns (type 2) and may range from 19 to 1000 kbp in length. The second genome type is a circular genome (about 20–1000 kbp) that also has a plasmid-like structure (1 kb) (type 3). The final genome type found in plants and fungi is a linear genome made up of homogeneous DNA molecules (type 5).
But this is only present when the cell divides. Researchers have now been able to model the structure of chromosomes when they are active. This is extremely important because the way that DNA folds up in chromosome structures is linked to the way DNA is used. Scientists have been able to develop the 3D structures of chromosomes in a single cell.
Five nucleobases—adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U)—are called primary or canonical. They function as the fundamental units of the genetic code, with the bases A, G, C, and T being found in DNA while A, G, C, and U are found in RNA. Thymine and uracil are distinguished by merely the presence or absence of a ...
The mitochondrion is commonly called "the powerhouse of the cell", [30] for its function providing energy by oxidising sugars or fats to produce the energy-storing molecule ATP. [ 31 ] [ 32 ] Mitochondria have two surrounding membranes , each a phospholipid bilayer , the inner of which is folded into invaginations called cristae where aerobic ...