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This was a major advance in the field of biology since little was known about animal structure up to this point compared to plants. From these conclusions about plants and animals, two of the three tenets of cell theory were postulated. 1. All living organisms are composed of one or more cells 2. The cell is the most basic unit of life
The description of the cells was evident from passages such as: [3] Some, however, appear to remain for a longer period; occasionally, although rarely, a cell-nucleui is here and there seen upon the side of a nerve (the white substance of which is completely developed), lying in the pale border, which surrounds the white substance.
Generally, a monosaccharide with n asymmetrical carbons has 2 n stereoisomers. The number of open chain stereoisomers for an aldose monosaccharide is larger by one than that of a ketose monosaccharide of the same length. Every ketose will have 2 (n−3) stereoisomers where n > 2 is the number of carbons.
A triose is a monosaccharide, or simple sugar, containing three carbon atoms. There are only three possible trioses: the two enantiomers of glyceraldehyde, which are aldoses; and dihydroxyacetone, a ketose which is symmetrical and therefore has no enantiomers. [1] Trioses are important in cellular respiration.
In mammals, major cell types include skin cells, muscle cells, neurons, blood cells, fibroblasts, stem cells, and others. Cell types differ both in appearance and function, yet are genetically identical. Cells are able to be of the same genotype but of different cell type due to the differential expression of the genes they contain.
Neurons, cells of the renal medulla and erythrocytes depend on glucose for their energy production. [70] In adult humans, there is about 18 g (0.63 oz) of glucose, [71] of which about 4 g (0.14 oz) is present in the blood. [72] Approximately 180–220 g (6.3–7.8 oz) of glucose is produced in the liver of an adult in 24 hours. [71]
Cellulose is an important structural component of plant's cell walls and glycogen is used as a form of energy storage in animals. Sugar can be characterized by having reducing or non-reducing ends. A reducing end of a carbohydrate is a carbon atom that can be in equilibrium with the open-chain aldehyde ( aldose ) or keto form ( ketose ).
The biological organisation of life is a fundamental premise for numerous areas of scientific research, particularly in the medical sciences. Without this necessary degree of organisation, it would be much more difficult—and likely impossible—to apply the study of the effects of various physical and chemical phenomena to diseases and ...