You must have tried a variety of food like beans, milk, popcorn, potatoes, spaghetti, peas, whole grains, barley, oats, brown rice, corn, and cherry pie in your diet plan. But, what is important is a balanced died. Do you remember the composition of a balanced diet?
Carbohydrate-rich foods are an essential component of a balanced diet. Carbohydrates provide glucose to the body, which is converted into energy for bodily functions and physical activity. From health point of view, we can consider two carbohydrate sources. One which is digested to give glucose and the other not so easily digestible. Carbohydrates from unprocessed or lightly cooked whole grains, vegetables, fruits, and beans promote good health by providing vitamins, minerals, fibre, and a variety of important phytonutrients. White bread, pastries, sodas, and other highly refined or processed foods are all unhealthy sources of carbohydrates. These foods contain easily digestible carbohydrates, which may contribute to weight gain, impede weight loss, and encourage heart diseases and diabetes.
There is a lot to know about these carbohydrates.
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Carbohydrates of sucrose, cellulose, starch, glucose, etc were isolated in Germany Their reactions with phenyl hydrazine to produce crystalline phenylosazone were carried out Fischer inicatingby reacting two phenyl hydrazine with the aldehyde group and the carbon adjacent to the aldehyde group.
Carbohydrates, which include sugars, fibres, and starches, are essential nutrients. Plants are the primary producers of carbohydrates. They are found in grains, vegetables, fruits, milk, and other dairy products. They are the fundamental food group required for a healthy lifestyle. Carbon (C), hydrogen (H), and oxygen (O) atoms make up carbohydrates.
Carbohydrates got their common name from the fact that they frequently have the formula CX(H2O)Y. They appeared to be 'carbon hydrates.' For example, the formula of glucose, C6H12O6, clearly fits into the general formula of carbohydrates, i.e., CX(H2O)Y.
So, can we say that all of the compounds that fit into the formula of CX(H2O)Y are carbohydrates?
'No,' is the answer to this question. There are compounds,-
Although acetic acid, CH3COOH is not a carbohydrate but it satisfies the general formula formula of carbohydrate(i.e C2(H2O)2)
As a result, we can conclude that carbohydrates cannot be explained solely using this formula.
Carbohydrates can also be defined as optically active polyhydroxy aldehydes or ketones or substances that hydrolyze to yield polyhydroxy aldehydes and ketones. Almost all carbohydrates are chiral and have optical properties. 1,3-dihydroxypropane is an exception to this rule. Simple carbohydrates are also referred to as saccharides or sugars.
Carbohydrates are classified according to three characteristics:
Carbohydrates Based on Hydrolysis Products:
Monosaccharides are further classified into two types based on the number of carbon atoms and functional groups present.
Based on the number of the monomeric unit formed during the hydrolysis Oligosaccharides are classified into disaccharides, trisaccharides, tetrasaccharides etc
Disaccharides are formed when two monosaccharides are joined together or when carbohydrates are hydrolyzed to produce only two molecules of monosaccharides.
For example, hydrolysis of one molecule of sucrose yields one molecule of glucose and one molecule of fructose.
Furthermore, when maltose is hydrolyzed, it yields only two molecules of glucose, as shown below.
Complex carbohydrates are made from more than one sugar molecules. Complex carbohydrates molecules are digested slowly than simple carbohydrates like glucose and sucrose They are abundant in potatoes, wheat, rice, beet root and fruits.
Here are some examples of polysaccharides.
Classification based on Reducing Nature:
Carbohydrates can also be divided into two types based on their ability to reduce Tollens' and Fehling's reagents as reducing sugar and non-reducing sugar.
Reducing Sugar: It is a carbohydrate which reduces Tollens' and Fehling's reagent, and they must have at least one hemiacetal or hemiketal functional group.
Non-reducing sugar: Sugars that do not reduce Tollens or Fehling's solutions, should have an acetal linkage.
Note: Except for sucrose, all monosaccharides and oligosaccharides are reducing sugars; all polysaccharides are non-reducing sugars.
Q1. Which of the following is an example of a monosaccharide?
Solution: Monosaccharides are the simplest carbohydrates that cannot be hydrolyzed into simpler carbohydrates. Some important example of Monosaccharides includes- Glucose, fructose, ribose, etc.
Lactose is an example of a disaccharide and cellulose and starch is an examples of a polysaccharide. Therefore option (D) is correct
Q2. Select the correction option which is an example of a non-reducing sugar.
Solution: Non-reducing sugar: Sugars that do not reduce Tollens or Fehling's solutions, should have an acetal linkage. Except for sucrose, all monosaccharides and oligosaccharides are reducing sugars; all polysaccharides are non-reducing sugars. Therefore option (A) is correct.
Q3. Which of the following option is incorrect with respect to the carbohydrates?
A. Carbohydrates are optically active polyhydroxy aldehydes and ketones or substances that hydrolyze to yield polyhydroxy aldehydes and ketones.
B. All carbohydrates are represented by the general formula CX(H2O)Y.
C. Sucrose is an example of non -reducing sugar
D. Carbohydrates, which include sugars, fibres, and starches, are essential nutrients.
Solution: Carbohydrates are optically active polyhydroxy aldehydes and ketones or substances that hydrolyze to yield polyhydroxy aldehydes and ketones. Carbohydrates, which include sugars, fibres, and starches, are essential nutrients. It is generally represented by the general formula CX(H2O)Y but there are few molecule like CH3COOH is not a carbohydrate but it satisfies the general formula formula of carbohydrate(i.e C2(H2O)2). Rhamnose, C6H12O5, is a carbohydrate but does not satisfy the general formula of carbohydrates.
Sugars that do not reduce Tollens or Fehling's solutions, should have an acetal linkage are non-reducing sugar. Except for sucrose, all monosaccharides and oligosaccharides are reducing sugar.
Therefore, option (B) is incorrect.
Q4. Select the correct option which represents the example of Polysaccharide.
D. Both A and B are correct
Solution: They are carbohydrates that produce a large number of monosaccharide molecules (>10). They are also known as complex carbohydrates because they are made up of several monomers that have been polymerized together. Polysaccharides are carbohydrates that have a lot of branching and are homopolymers, such as starch, glycogen, and cellulose (made up of just glucose units). Therefore, option (D) is correct.
Q1 . What are the main sources of carbohydrates?
Answer: Carbohydrates can be obtained from a variety of sources. Some of them are detailed below.
Q2. What are the functions of carbohydrates?
Answer: Some important functions of carbohydrates includes:
Q3. What are simple and complex carbohydrates?
Answer: The primary distinction between simple and complex carbohydrates is that simple carbohydrates are rapidly digested and absorbed by the body, whereas complex carbohydrates take longer to digest. Simple carbohydrates are small molecules while complex carbohydrates are polymeric in nature.
Q4. How are carbohydrates digested?
Answer: Carbohydrate digestion starts in the mouth and ends when the polysaccharides are broken down into single sugars, or monosaccharides, that the body can absorb.
Salivary glands secrete the enzyme salivary amylase, which initiates the breakdown of polysaccharides in carbohydrate food.
The pancreas releases the enzyme pancreatic amylase in response to the presence of chyme in the duodenum, which breaks the polysaccharide down into a disaccharide. The enzymes lactase, sucrase, and maltase are then produced by the small intestine to break down the disaccharides into monosaccharides.
Carbohydrates that were not digested and absorbed by the small intestine reach the colon, where intestinal bacteria break them down partially. Fibre is excreted with faeces or partially digested by intestinal bacteria.