Types Of Polysaccharides

Classification of Polysaccharides Storage polysaccharides are those that are used for storage. For instance, plants store glucose in the form of starch. Animals store simple sugars in the form of glycogen. Structural polysaccharides are carbohydrates that have a structural role.

Usually, the structure of polysaccharides is six-carbon repeating monosaccharides linked together by oxygen. The chemical formula is often (C6H10O5)n, where the n is a number larger than 40. The specific formation of the polysaccharide is dependent upon its use.

They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch, glycogen and galactogen and structural polysaccharides such as cellulose and chitin. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit.

Polysaccharide Functions The three main functions of polysaccharides are providing structural support, storing energy, and sending cellular communication signals. The carbohydrate structure largely determines its function.

• Glycogen: It is made up of a large chain of molecules.
• Cellulose: The cell wall of the plants is made up of cellulose.
• Starch: It is formed by the condensation of amylose and amylopectin.
• Inulin: It is made up of a number of fructofuranose molecules linked together in chains.

All monosaccharides have the same general formula of (CH2O)n, which designates a central carbon molecule bonded to two hydrogens and one oxygen. The oxygen will also bond to a hydrogen, creating a hydroxyl group. Because carbon can form 4 bonds, several of these carbon molecules can bond together.

Structure and nomenclature. With few exceptions (e.g., deoxyribose), monosaccharides have this chemical formula: (CH2O)x, where conventionally x ≥ 3. Monosaccharides can be classified by the number x of carbon atoms they contain: triose (3), tetrose (4), pentose (5), hexose (6), heptose (7), and so on.

The two main functions of monosaccharides in the body are energy storage and as the building blocks of more complex sugars that are used as structural elements. Monosaccharides are crystalline solids that are soluble in water and usually have a sweet taste.

Monosaccharides are classified according to three different characteristics: the location of their carbonyl group, the number of carbon atoms they contain, and their chiral property. If the carbonyl group is an aldehyde, the monosaccharide is an aldose. If the carbonyl group is a ketone, the monosaccharide is a ketose.

The figure below shows the most common monosaccharides: glucose, fructose and galactose (six-carbon monosaccharides), and ribose and deoxyribose (five-carbon monosaccharides). Note that they are all named using the suffix –ose, which means sugar.

Classify monosaccharides as aldoses or ketoses and as trioses, tetroses, pentoses, or hexoses. Distinguish between a D sugar and an L sugar.

The simplest monosaccharides are said to be the trioses which are the two three-carbon trioses. We can have three possible trioses: L-Glyceraldehyde, D-Glyceraldehyde, and dihydroxyacetone or just glycerone.

Glucose

: a sugar that is not decomposable into simpler sugars by hydrolysis, is classed as either an aldose or ketose, and contains one or more hydroxyl groups per molecule. — called also simple sugar.

A monosaccharide is a carbohydrate consisting of one sugar unit. Common examples of simple sugars or monosaccharides are glucose and fructose. 2: Glucose and fructose are monosaccharides, or simple sugars. Glucose and fructose are both very soluble in water.

Monosaccharides

• Honey.
• Dried fruits such as apples, dates and sultanas.
• Fruit jams, chutney’s, barbecue & plum sauce, gherkins, sundried tomatoes.
• Breakfast cereals with whole wheat, oats and fruits.
• Canned fruits such as pineapple, strawberry and plum.
• Fresh fruits including grapes, apples, pear, kiwi & banana.

Oligosaccharides are formed when two or more monosaccharides join together by O-glycosidic bonds. Examples include sucrose, lactose and maltose.

Sucrose consists of a glucose and a galactose unit. So, it is a disaccharide and not a monosaccharide.

The major dietary source of galactose is lactose, a disaccharide formed from one molecule of glucose plus one of galactose. Lactose is found only in milk; after weaning, significant quantities of dietary lactose are found only in dairy products (Table 1).

Solution. Among the given carbohydrates, fructose is a monosaccharide.

This is the storage form of glucose in animals and humans which is analogous to the starch in plants. Glycogen is synthesized and stored mainly in the liver and the muscles….

Cellulose is a polysaccharide.

There are 3 monosaccharides: Glucose. Fructose. Galactose.

Common Naturally Occurring Monosaccharides

• Glucose or dextrose.
• Fructose.
• Galactose.
• Mannose.
• Ribose and deoxyribose.

All monosaccharides are reducing sugars because they either have an aldehyde group (if they are aldoses) or can tautomerize in solution to form an aldehyde group (if they are ketoses). This includes common monosaccharides like galactose, glucose, glyceraldehyde, fructose, ribose, and xylose.

Simple sugars are called monosaccharides, made up of single sugar molecules. Examples of these are glucose, fructose, and galactose. When two simple sugars are joined together by a chemical bond they are called disaccharides, the most common of which is sucrose or table sugar.

Simple sugars are carbs with one (monosaccharide) or two (disaccharide) sugar molecules. Many healthy foods like fruit and vegetables naturally contain sugar and shouldn’t be avoided as they benefit your health. However, excess added sugar is linked to obesity and increased heart disease and cancer risk.

Carbohydrates are sugars that come in 2 main forms – simple and complex. This is also referred to as simple sugars and starches. The difference between a simple and complex carb is in how quickly it is digested and absorbed – as well as it’s chemical structure.