I am a Christian. I believe in the God of the Bible, in God the Father, in His Son Jesus Christ, and in the Holy Spirit. I believe in Genesis 1:1 - "In the beginning God created the heavens and the earth. (NIV)" I am a biochemist and a pharmacist by education. As such I have a desire to understand nature. I am writing this blog as my way to express the facts of true science as I understand them, from the perspective of one who believes that all things were created by God, for God and for His purposes.

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Thursday, October 20, 2011

Cellulose - That Cotton-Picking Carbohydrate!

When my kids were young we went to carnivals and fairs and would often get that sticky pink web of sugar called cotton candy. It consisted of air that dissolved on your tongue with the sweet taste of spun excitement. Well it got its name because the soft fluffy appearance of the sugary stuff looks very much like an open cotton boll, the seed capsule of the cotton plant. Cotton and cotton candy have more in common than just their good looks, however. Cotton is primarily cellulose, a carbohydrate made up of thousands of glucose molecules and cotton candy is made from sucrose, a disaccharide made from glucose and fructose.

Cotton is the soft, fluffy fiber found inside that cottonseed capsule. The cotton plant is native to tropical and subtropical regions of the world, including the Americas, Africa, and India. Cotton has been spun, woven, and dyed since prehistoric times. It clothed the people of ancient India, Egypt, and China. Cotton was domesticated over 7000 years ago but was not widely used until the invention of the Cotton Gin, a device for removing the seeds from the fibers, in 1793 by Eli Whitney. The cottonseed, which remains after the cotton is ginned, is used to produce cottonseed oil that can be consumed like any other vegetable oil. Cotton fiber is now most often spun into yarn or thread and used to make a soft, breathable cloth. It is the most widely used natural fiber in clothing today.

There are two species of cotton that account for 98% of all cotton production. They are Upland cotton (90%), native to North and Central America, and Egyptian or Pima Cotton (8%), native to South America. The remaining cotton comes from Africa and the Middle East. Although the name Egyptian cotton is sometimes associated with a higher quality product, most products bearing that name are not made with the finest cottons from Egypt. The five leading exporters of cotton are the United States, India, Brazil, Australia, and Uzbekistan. The largest importers are Korea, Taiwan, Russia, Hong Kong and Japan.

Cotton is 91% cellulose (plus 8% water), compared to 40-50% for wood. Cellulose is a polysaccharide consisting of linked glucose units with the formula (C6H10O5)n. Cellulose from wood has typical chain lengths between 300 and 1700 glucose units; cotton and other plant fibers have chain lengths ranging from 800 to 10,000 units. Cellulose is the principal structural component of the cell wall of green plants with 33% of all plant material being made of cellulose. It is the most common organic compound on Earth.

By the mid-1800s, cotton had become the chief plantation crop in the southern United States. Cultivating and harvesting cotton was the leading occupation of slaves. Cotton remained key even after the end of the Civil War as cotton plantations required vast labor forces to hand-pick cotton. It was not until the 1950s that reliable harvesting machinery was introduced into the South.

In North America, the most economically destructive pest affecting cotton is the boll weevil. The cotton industry relies heavily on chemicals, such as herbicides, fertilizers and insecticides. Genetically modified cotton, produced by Monsanto, was developed to reduce the heavy reliance on pesticides and to resist Roundup®, used to control weeds, also sold by Monsanto. Monsanto thus controls the cotton market by selling the seeds and the chemicals used to improve the crop yields.

A very small number of farmers are now moving to organic production, and organic cotton products are available for purchase in limited numbers. Organic cotton is considered cotton from plants that are not genetically modified and are grown without the use of any synthetic fertilizers or pesticides.

Cotton has a number of "competitors" that have been developed over the last hundred years. The first was rayon, developed in France in the 1890s. Rayon is derived from natural cellulose, but requires extensive processing. A succession of synthetic fibers were then introduced by the chemical industry. Acetate fiber was developed in 1924. DuPont introduced nylon in 1936, followed by acrylic in 1944. It was not until the introduction of polyester in the early 1950s, however, that cotton came under threat of market share. While many fabrics are still made completely of cotton, some materials blend cotton with these other fibers to produce a wide variety of fabric choices. Check them out at your favorite department store soon but be sure to wait for the next sale!

"Besides, who would patch old clothing with new cloth? For the new patch would shrink and rip away from the old cloth, leaving an even bigger tear than before. Mark 2:21 (NLT)"

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