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Natural Polymers

Natural Polymers. Plants are made of a polymer called cellulose. And many plants also make starch . Potatoes, corn, rice, and grains all have a lot of starch. Starch is also a polymer.

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Natural Polymers

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  1. Natural Polymers • Plants are made of a polymer called cellulose • And many plants also make starch. Potatoes, corn, rice, and grains all have a lot of starch. • Starch is also a polymer. • Cellulose and starches are both made from sugars - so they're called polysaccharides (meaning "many sugars"). • Another useful natural polymer produced by plants is rubber. • Natural rubber's scientific name is polyisoprene

  2. The amount of cellulose in fibres varies according to the source • And is usually associated with water, wax, pectin, protein, lignin • The DP of cotton cellulose 15,000 • Wood cellulose DP 10000 • Certain bacteria synthesize cellulose • Cellulose Derivatives • Cellulose esters • – cellulose nitrate first commercial polymer • Manufatcure of explosives, photographic films

  3. Starch – glucose linked through carbons 1 and 4 by alpha linkage. Consists of amylose (30,000 to 1 million) and amylopectin (over 1 million) Partial structure for amylopectin

  4. Physiologically Active Natural Polymers

  5. Protein • One natural polymer that we eat a lot of is also one we are made of - PROTEIN! • Protein also forms some of the things we wear - namely leather, silk, and wool. • Protein is a natural polymer formed from molecules called amino acids. • Protein is the main thing in skin, organs, muscles, hair and fingernails. • The most common protein in the body, collagen, is used for support and structure. • It's in-between all the cells in the body, all around the organs, even in the teeth and bones.

  6. Protein Structure • Proteins are polyamides with alpha-amino acids being the monomer units. • More complex than polysaccharides • The amino group that form peptide linkage in mammalian proteins – located on alpha carbon • All amino acids have the L configuration • They exist as zwitterions (dipolar ions) • Two major groups , fibrous and globular

  7. Like nylon, proteins are polyamides. They have a repeat structure like Each repeat unit in a protein may be different. The body builds proteins from twenty different amino acids . The group R in the diagram above is different in each amino acid. A given protein may contain all twenty, in a precise sequence consisting of thousands of amino acid repeat units.

  8. Common Amino acids

  9. Fibrous Proteins • Held together as fibrils by hydrogen bonds • Structural material of animal tissues • Ex keratin, collagen, silk, myosin • Globular Proteins • Folded and more compact • Intramolecular secondary bonding forces • Soluble in water • Hormones, hemoglobin, egg albumin

  10. Alpha helix of α- keratin Pleated sheet structure (ß- arrangement of silk fibroin)

  11. Silk • Silk protein - a sort of fiber made by special caterpillars. • This stuff has been used to make beautiful fabric for clothing. • Nylon- synthetic silk. • Spider silk is incredibly strong for its weight, and scientists have been working hard to mimic this fiber, too. • Enzymes • Each enzyme is a protein that catalyze a specific reaction in the body, and does it really really fast. • Without enzymes, these reactions either just wouldn't happen, or would go way too slowly to make life possible! • Some enzymes even make other enzymes.

  12. Chitin • Chitin is the strong waterproof polymer that crustaceans like crabs and shrimp and all kinds of bugs make to form their protective outer shells. • It's even found in the cell walls of mushrooms. • Its structure is like cellulose. • Scientists have found a way to purify the chitin into an off-white powder that can be useful to farmers, doctors, and even in food as a thickening agent. From what you know now about natural polymers, can you guess which two are the most common in the whole world? The most common natural polymer is CELLULOSE, and the second most common is CHITIN

  13. Chemically, chitin is poly(N-acetylglucosamine). Here's it's structure:

  14. DNA and RNA Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are polymers we can't live without. The DNA is the blueprint that determines everything about your body. DNA is passed from parents to their children, so children inherit the physical characteristics of their parents. RNA helps the blueprints of DNA to be carried out.

  15. DNA has a spiral staircase-like structure. The steps are formed by the nitrogen bases of the nucleotides where adenine pairs with thymine and cytosine with guanine. The chemical structure of DNA. Hydrogen bonds are shown as dotted lines.

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