Furthermore, if the monosaccharide has an aldehyde group, it is called aldose. A monosaccharide with a keto group is called a ketose. Overview and Key Difference 2. What is Glucose 3. What is Galactose 4. Glucose is a monosaccharide that contains six carbon atoms and an aldehyde group. Therefore, it is a hexose and an aldose. It has four hydroxyl groups and has the following structure. Though it is shown as a linear structure, glucose can be present as a cyclic structure too.
In fact, in a solution, the majority of molecules are in the cyclic structure. When a cyclic structure is formed, the -OH on carbon 5 is converted into the ether linkage to close the ring with carbon 1.
This forms a six-member ring structure. We need a special enzyme, lactase, to break this bond, and the absence of lactase activity leads to lactose intolerance. Food manufacturers are always searching for cheaper ways to produce their food.
One method that has been popular is the use of high-fructose corn syrup as an alternative to sucrose. Nevertheless, because an increase in high-fructose corn syrup consumption see figure below has coincided with the increase in obesity in the U. Opponents claim that high-fructose corn syrup is contributing to the rise in obesity rates. As a result, some manufactures have started releasing products made with natural sugar. You can read about this trend in the following New York Times article in the link below.
Also, manufacturers tried to rebrand high-fructose corn syrup as corn sugar to get around the negative perception of the name. But the FDA rejected the Corn Refiners Association request to change the name officially to corn sugar as described in the second link. It is stored inside the body in bulk form at a place called hemicellulose. Whenever there will be an additional requirement of galactose than the process of hydrolysis takes place and galactan is eventually converted into galactose.
Coming back to glucose, besides D-glucose there is one more glucose, which is biologically inactive. The inactive form of glucose is termed as L-glucose. It is not possible to metabolize the molecules of L-glucose by the process called glycolysis. Glucose and galactose are also synthesized by the body. However, the external sources will vary from each other. Glucose can be divided into two types: simple carbohydrate and complex carbohydrate.
Simple carbohydrates easily get to digest and their main sources include fruits and their juices, alcoholic beverages, sweets and table sugar. Complex carbohydrates get digested slowly. Galactose has a higher melting point than glucose as a result of the structural differences. The main difference between these two sugars from a sensory perspective is that glucose is substantially sweeter, though neither is as sweet as table sugar.
Very few foods naturally contain glucose and galactose, with the exception of sweeteners like honey. However, longer chains of carbohydrates that contain glucose and galactose are very common in the food supply. The main sources of glucose are fruits and dried fruit such as raisins and apricots; fruit juices; and sweeteners like honey. The main source of galactose is foods containing lactose, such as dairy products, though it does occur naturally in honey and beets.
Lactose is broken down to generate galactose and glucose before it is absorbed in the intestine. Starches, which are long strings of sugars, and big sugars like lactose are composed of smaller building block sugars like glucose and galactose. During the digestion of these larger sugar structures, glucose and galactose are released.
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