Carbohydrates , carbohydrates everywhere!! My reflections

Hi all so this is my reflection on carbohydrates, now I also did a video review on carbs that had alot of interesting stuff , so you go ahead and check it out okay. 🙂 

Carbohydrates – A group of organic compounds whose molecules contain atoms of carbon, hydrogen and oxygen only. 

There are three types of carbohydrates. 

Monosaccharides they are also known as simple sugars.

These are basically the simplest type of carbohydrates, there general formula is (CH2O)n. They dissolve in water to give sweet tasting solutions, when present in a solution they can reduce other chemicals so they are known as reducing sugars. There are many different monosaccharides due to the different number of atoms present ,also the spacial arrangement of them. Some common ones are : 

Trioses example glyceraldehyde 

Pentoses example ribose 

Hexoses example glucose , fructose and galactose. 

Disaccharides they are also known as double sugars 

When two hexose sugar molecules (6 Carbon) react together by a condensation reaction, they form a disaccharide. It is also reversible and the new disaccharide can be converted back into two hexose by a hyrolysis reaction. The bond that forms between the two sugars is know a glycosidic bond. So for example if the bond was formed between carbon 1 and 4 , the bond will be called 1,4 glycosidic bond. These sugars have the formula C12H22O11. And just as a monosccharide it dissolves in solution to give a sweet tasting solution. Some common disaccharides are : 

Maltose formed from two  alpha-glucose 

Lactose formed from alpha-glucose and galactose

Sucrose formed from alpha-glucose and fructose 

While all disaccharides are reducing sugars , sucrose is a non – reducing sugar and this is due to the glycosidic bond in sucrose. Because the anomeric carbons of glucose and fructose are locked up within the bond it cannot be classified as a reducing sugar. 

Polysaccharides they are also known as many sugars.

 

They are more complexed than monosaccharides and disaccharides, and consist of larger molecules. They form long chains that are made up of many monosaccharides, they are called condensation polymers. They are insoluble in water and are neither sweet nor are ‘sugars’. There formula being (C6H10O5)n . Some common examples are:

Starch-  This is an energy store in plants. 

It is a polymer of glucose , which means that it is made from glucose, formed in the plant cells, they are in the form of grains. Because they store food they are insoluble and compact, but can be broken down during a hydrolysis reaction to release the stored food.

It is a mixture of two types of chains

Amylose – Long unbranched chains forming 1, 4 glycosidic bonds. Taking the shape of a helical configuration, each monomer has a bulky side group which has to be accommodated. It forms 20% of starch. 

Amylopectin – Branched and form 1,4 along with 1,6 glycosidic bonds. They contain 1500 monomers with branches every ten units. And forms about 80% of starch. This proportion is not fixed and can vary from one species to another. 

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Glycogen – Found in animals , forms 1,4 and 1,6 glycosidic bonds as well. However the chains are more branched and shorter than amylopectin. Glycogen contains no unbranched chains.  It is a storage product of glucose, it takes the shape of small granules suspended in the cytoplasm , cant be seen in liver and muscle cells. Because of its short length it can hydrolysed rapidly, for an animal’s urgent need. 

Cellulose – Mainly for structural purposes, because it doesnt store food but is needed for structure its more fibrous and strong, it is the major component of plant cell walls. It forms 1,4 glycosidic bonds but instead of having alpha – glucose like starch and glycogen , cellulose has beta – glucose , in order for the appropriate -OH groups to react it needs to alternate 180 degrees. Because the bulky side groups are accommodated on opposite sides alternately, the unbranched chains are straighter and hydrogen bonds form between the OH and the oxygen of adjacent chains. This is what gives cellulose its strong and fibrous structure.  

 

 

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