Polymers are huge molecules which are formed with the combination of smaller molecules which are joined together by the ends. These smaller molecules are known as monomers and help to form additional polymers. They play an important role in everyday life and are also present in different living things. They have properties in plastics and even the human DNA which are important for the existence of life. Polymers are formed from different substances and one of the most common one in this case is glucose. There are two different types of polymers which are formed from glucose and they are known as starch and cellulose. Both of these are made from the same monomer and the same units which are required but still there are few differences between them which make them distinct in their own way. The main variation between these two types of polymers is that in starch all the units of glucose follow the same direction as others and do not deviate from their path. For cellulose, all the glucose units are at the angle of 180 degrees and rotated at the same rate on the axis. Both of these are needed to compensate the energy requirement in the world and also belong to the same group but there are also differences in the way they are linked together. In starch the glucose units are linked together with the help of glycoside linkage while they are joined together with the alpha 1.4 linkage for cellulose. Another difference is in the appearance where grain is the form in which starch exists while fiber is the form in which cellulose exists. There are also variations in the physical and chemical properties of both these. Both of these use different monomer. The main one for starch is a-glucose while the main one in cellulose is b-glucose. The bonding such as amylose and amylopectin is only available in starch while is absent in glycogen. There are many branched chains which are smaller in size, while some of them are coiled together for starch while the nature of chains in cellulose is unbranched chains which are longer in length and form H-bonds. The main function of starch in plants is the energy storage in the form of carbohydrates while the main function of cellulose in plants is structural changes. Starch exists in the form of grains while cellulose is available in the form of fibers. There are many other differences between them too which will be listed at the end. A brief description of both these types of glucose polymers is given below.
Definition of Starch
This word was originated from German language and means strength, or to stiffen something. It is therefore linked with the main molecule of glucose. Starch is one of the type of glucose polymers which is formed by the combination of glucose molecules which follow the same trajectory and do not change their path, they are available in the form of grains and are the most abundant type of carbohydrate which is available in plants and human body. Their main role is to store energy in the form of carbohydrates therefore they are favorable for humans and plants alike. They are most commonly found in food items such as potato, wheat and rice. The normal color of starch is white and there are two different types of molecules in it which are branched together, these branches are smaller in size. Usually around 1000 glucose molecules are required to form a single starch molecule which face in the same direction as all others.
Definition of Cellulose
This was discovered in 1838 from the plant matter and was used to produce thermoplastic for the first time and therefore has many applications. It was chemically synthesized for the first time at the end of 20th century and is an important component in plants and cell walls. It has more applications in plants and objects than human beings. It is used to produce paper and can be converted in to different products such as rayon. For its use in industry is obtained from cotton and wood. It takes around 500 molecules of glucose to form one cellulose molecule, these have no proper arrangement and are usually deviated at an angle of 180 degrees from their axis. Because of this pattern, hydrogen bonding between them takes place which attracts the hydrogen and oxygen molecules. It is therefore stronger than the starch molecule because of the bonding although it is smaller in size.
Differences in a Nutshell
- Both have different types of monomers. Starch uses a-glucose monomer while cellulose uses b-glucose monomer.
- It takes around 200-1000 molecules of glucose to form one molecule of starch while it takes 500 molecules of glucose to form one molecule of starch.
- The nature of chain in starch is that amylose is coiled together in unbranched manner while amylopectin is chained together and is longer in size. For cellulose the chains are long and unbranched.
- There is hydrogen bonding between cellulose molecules while it is not the case with starch.
- Cellulose molecules are rigid than the starch molecules.
- Main role of starch is to store energy in the form of carbohydrates while the main role of cellulose is to form a specific structure of plants.
- Starch is mostly found in human bodies and food items while cellulose is mostly found in plants.
- Starch is mostly found in granular form while cellulose is mostly found in fibrous state.
How food is stored in the body of humans and plants is of extreme interest for people who are involved in the subject and have the aim of knowing more. There are many differences between the processes and the way they are stored in the form of starch and cellulose and this article has explained all those differences clearly.