• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Biology essay --- Starch, cellulose and glycogen are all polysaccharides; however they differ in the role they play in living cells. These differences are most likely related to the differences in their structures. What are their uses, and how so their us

Extracts from this document...

Introduction

Biology Essay "Starch, cellulose and glycogen are all polysaccharides; however they differ in the role they play in living cells. These differences are most likely related to the differences in their structures. What are their uses, and how so their uses relate to their structures?" Starch, cellulose and glycogen are all polymers of glucose monomers, polysaccharides joined together by dehydration synthesis. All of them play different roles in living cells --- starch and cellulose in plant cells cell wall and glycogen in cells of human skeletal muscle and liver and some fungi . Starch and glycogen are both made from alpha-glucose, which is an isomer of glucose in which the hydroxyl (-OH) group attached to carbon number 1 is below the plane of the ring. Starch is used as an energy reserve in plants, it is found commonly in everyday food we consume, such as potatoes, rice and yams. Starch is a polysaccharide carbohydrate consisting of a large number of glucose monosaccharide units joined together by glycosidic bonds. It composed of two kinds of polymer: amylose and amylopectin. Amylase is a helical alpha-glucose chain without branches, with a molecular weight ranging from 4000 to 150000. ...read more.

Middle

Glycogen is created when there are high blood sugar levels and excess glucose in the body. The pancreas secretes insulin, which stimulates the creation of glycogen from glucose and signals the body to use glucose as its main form of energy. Cellulose is made from beta-glucose, an isomer of glucose in which the hydroxyl group attached to carbon 1 is above the plane of the ring. Cellulose is the structural component of the primary cell wall of green plants. It has a much more rigid structure than starch or glycogen, as the glucose monomers are linked by 1, 4 glycosidic bonds of beta-glucose, which produce a very straight chain. the beta-1,4 glycosdic bond is stick outward between each beta-glucose unit , which enable the linkage of hydrogen bond with other beta-blucose units surrounding it , thus the hydrogen bond is actually giving the mechanical strength for cellulose. It is highly insoluble in water, and most organisms can not produce enzymes to break it down. Cellulose is highly permeable , hence materials are able to move in or out of the cellulose cell wall freely. Beta-glucose unit in cellulose is paralel array , which there are some microfibrils formed. ...read more.

Conclusion

It is composed of � glucose molecules, which create a more rigid structure when joined than the ? links found in energy storage glycogen and starch molecules. The reason for this is that when you make 1-4 glycosidic bonds with beta glucose it creats a very straight chain. The chains of cellulose lie close to each other so you get hydrogen bonding between the chains. This makes the molecule very stable and highly resistant to breakdown. You are porobably wearing cellulose as you sit here and read this. Cotton used to make clothes etc is cellulose from around the seeds of the cotton plant. Fibre helps the plant keep a strong structure. Humans can't digest fibre, but it is an important part of a healthy diet, because it helps the digestive tract by giving it more to push on. This helps the contents move through at a reasonable rate. It also helps to stop too much water being absorbed in the large intestine and so reduces constipation. It also feeds the bacteria in your large intestine. These bacteria are not bad, they are good. They can digest some of the cellulose and other molecules your enzymes can not. Half the weight of your poo may be bacteria! But with out healthy bacteria you are less likely to have a healthy gut, so keep eating the fibre! ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. biology extended essay - How different diets: vegetarian, vegan and a meat centered diet ...

    Most products produced by animals such as eggs, fish, meat, poultry contain high amounts of proteins, consuming these foods help supply the body with adequate and sufficient amounts of all the amino acids needed by the body. A meat centered diet contains significant amounts of zinc which is important for a healthy immune system.

  2. Biology- Extended essay. For this research, I investigated the effects of DDT and ...

    The results under the Azo-Dye solution first began to show an immense decline under the initial concentration of the Azo-Dye as compared to DDT which only started with a decline of 20 opercular movements. However, with increasing concentrations, I observed that DDT had a much greater impact on the opercular movement as compared to the Azo-Dye.

  1. Penicillin - its discovery, properties and uses.

    However, due to poor knowledge about medicine, they couldn't distinguish or distill the efficacious component in the moulds. The moulds involved in many old treatments. Around 1550 BC in Egypt, an Egyptian physician, stated that if a "wound rots...then bind on it spoiled barley bread"8.

  2. Environmental Factors affecting plant growth

    This shows that the plants grew very slowly even after the supply of all the minerals. Evaluation Most of the results that I achieved do not support my hypothesis. They suggest that the deficiency of phosphorus leads to healthy plant growth which is something that I am not sure about.

  1. Biology Extended Essay 2009

    Hence the research question is narrowed down to "How well can processed orange juice be consumed in substitution of freshly squeezed orange juice, in term of its nutritional value and its impact on human health". This directly links under a subject of diet and nutrition and also associated many biochemical

  2. IB Genetic Unit Notes

    Found in Europe and US. Benefits: - damaged caused by insects are reduced - Bt corn is slightly more expensive, but the difference is less than on extra application of insecticide - Non- Bt corn needs to be checked often for signs of insects - therefore less checking of corn.

  1. Extended Essay- How is production of carbon dioxide (CO2) during digestion affected by the ...

    * Organic evaporated cane juice - organic sugar (.94g per trial) * Truv�a (.94g per trial) * Splenda (.94g per trial) * Yeast (1.0g per trial) * Tap water at 20?C (50mL per trial) * Two 100mL Graduated Cylinders * Ring stand * Ring stand clamp Procedure: 1.

  2. IB Biology Digestive System

    It is full of bacteria, which are obligate anaerobes, and the bacteria?s break down non-digestible material and produce both vitamins and minerals to be absorbed. 5. Describe how the stomach is utilized for both mechanical and chemical digestion. Both mechanical and chemical digestions are processes of the digestive system that

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work