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In carbohydrate chemistry carbohydrate acetalisation is an organic reaction and a very effective means of providing a protecting group. The example below depicts the acetalisation reaction of D-ribose 1. With acetone or 2,2-dimethoxypropane as the acetalisation reagent the reaction is under thermodynamic reaction control and results in the ...
Since many sugars are polyhydroxy aldehydes and ketones, sugars are a rich source of acetals and ketals. Most glycosidic bonds in carbohydrates and other polysaccharides are acetal linkages. [2] Cellulose is a ubiquitous example of a polyacetal. Benzylidene acetal and acetonide as protecting groups used in research of modified sugars.
A column of porous black graphite formed during the experiment. Carbon snake experiment. The carbon snake is a demonstration of the dehydration reaction of sugar by concentrated sulfuric acid. With concentrated sulfuric acid, granulated table sugar performs a degradation reaction which changes its form to a black solid-liquid mixture. [1]
Approximately 80-90% of the hydroxyl groups of wood are modified during the process. The whole process is an environmentally friendly treatment, and has emerged, in the 21st century, as a significant innovation in the scientific area of wood science. [15] [16]
Gregor Mendel's experiments with the garden pea led him to surmise many of the fundamental laws of genetics (dominant vs recessive genes, the 1–2–1 ratio, see Mendelian inheritance) (1856–1863). Charles Darwin demonstrates evolution by natural selection using many examples (1859).
The general structure of a hemiacetal (left) and hemiketal (right). In organic chemistry, a hemiacetal is a functional group the general formula R 1 R 2 C(OH)OR, where R 1, R 2 is a hydrogen atom or an organic substituent.
Carbohydrase is the name of a set of enzymes that catalyze five types of reactions, turning carbohydrates into simple sugars, from the large family of glycosidases. [1] Carbohydrases are produced in the pancreas, salivary glands and small intestine, breaking down polysaccharides.
Molisch test (using α-napthol) indicating a positive result (see purple ring). Molisch's test is a sensitive chemical test, named after Austrian botanist Hans Molisch, for the presence of carbohydrates, based on the dehydration of the carbohydrate by sulfuric acid or hydrochloric acid to produce an aldehyde, which condenses with two molecules of a phenol (usually α-naphthol, though other ...