KEAM Reason: Intermolecular hydrogen bonding is present in them. AIIMS In aqueous solution, an amino acid exists as KEAM Which vitamin is fat soluble? The one letter code for the amino acid tryptophan is KEAM Chemistry Most Viewed Questions. Identify a molecule which does not exist. You may use sugar on a daily basis by adding it to your recipes and hot beverages to make them sweeter, but there's much more to this white substance than its sweet flavor. Plus, not all sugars have the same chemical properties.
While all sugars are soluble, not all sugars are reducing. To understand why sucrose that's the stuff you add to your favorite hot beverage is a non-reducing sugar, you have to know the difference between reducing sugar and non-reducing sugar.
Sucrose is a non-reducing sugar because its chemical structure does not allow certain organic compounds to form a hemiacetal. Sugar is a natural carbohydrate that provides the body with energy.
The most common sugar in the body is glucose, which plays an important role in the function of the brain, organs and muscles.
Sucrose exists naturally in foods and breaks down in the body in the same way as glucose. All the sugar you have in your pantry, such as caster sugar, icing sugar and demerara, is a manufactured form of sucrose.
A reducing agent is a compound like sugar or an element like calcium that loses an electron to another chemical type in a redox chemical reaction.
Reducing sugars, like glucose and lactose, have free ketone or aldehyde functional groups, which enable the formation of a hemiacetal, a carbon connected to two oxygen atoms: an alcohol OH and an ether OR.
You can oxidize a reducing sugar with mild oxidizing agents, such as metal salts. The redox processes are the wide range of reactions that include the majority of the chemical and biological processes taking part around us. Rusting and dissolution of the metals, browning of the fruits, fire reactions, respiration and the process of photosynthesis are all oxidation-reduction processes.
The redox reactions involve the transfer of hydrogen, oxygen, or electrons where two very important characteristics are common in all three reactions. Secondly , they always involve a net chemical change where new substituents are formed by the reaction of reactants. The examples of all three forms of chemical reaction have been elaborated on below. Two very important tests are often performed to identify the presence of reducing sugar.
These tests are the Benedict test and the Fehling test. After around ten minutes the solution starts to change its color. If the color changes to blue it means that there is no reducing sugar present.
But if the color changes to green, yellow, orange, red, and then finally to dark red or brown color confirms the presence of reducing sugar in the food. The chemical composition of the Benedict solution states that it is made of an anhydrous solution of sodium citrate, sodium carbonate, and copper II sulfate pentahydrate. During its reaction with the reducing sugar, the blue copper sulfate in the solution is converted into red-brown copper sulfide.
It is worth mentioning here that these tests only show the qualitative analysis of reducing sugar. In the Fehling test, the solution is warmed until the sample where the availability of reducing sugar has to be tested is homogeneously mixed in water after which the Fehling solution is added. If the reducing sugar is present the color of the solution will be changed to a red precipitate color resembling rust.
This test is specifically used for the identification of monosaccharides, especially ketoses and aldoses. These tests can be used in the laboratory for the determination of reducing sugar present in the urine which can be used to diagnose diabetes mellitus.
It must be noted here that the reduction of aldehydes results in the formation of primary alcohols while the reduction of ketones gives secondary alcohols.
The most common example of reducing sugar and monosaccharides is glucose. In the human body, glucose is also referred to as blood sugar. It is essential for the proper functioning of brains and as a source of energy in various physical activities. Another reducing sugar is fructose, which is the sweetest of all monosaccharides.
Galactose is another example of reducing sugar. It is a component of lactose available in many dairy products. Moreover, the list of reducing sugars also includes maltose, arabinose, and glyceraldehyde. Carbohydrates, especially reducing sugar are the most abundant organic molecules that can be found in nature. They have a wide range of functions in biology.
They provide a significant fraction of daily used dietary calories in most of the living organisms living on the earth. Also, their major role is to act as the storage of energy in living bodies. Read: Glycolysis , Fermentation , and Aerobic respiration.
Carbohydrates also serve as one of the cell membrane components and function primarily in mediating various intermolecular communications in the bodies of living organisms. Lastly, via Maillard reactions, carbohydrates are responsible for determining the crust color and the taste of the food such as coffee, bread, and roasted food items.
There are many uses of reducing sugar in our daily life activities. In medicines, the Fehling solution has been used as a test to detect diabetes in human blood. The relative measurement of the number of oxidizing agents reduced by the available glucose makes it easy to calculate the concentration of glucose present in the human blood or urine. Moreover, after the calculation of the exact amount of glucose present, it becomes easier to prescribe the amount of insulin that must be taken by the patients from the doctors.
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