Chemistry 30: Organic Reactions and Biochemistry

1. Chemistry 30: Organic Reactions and Biochemistry Christopher Chui Organic Reactions and Biochemistry - C. Chui

2. Organic Reactions • Substitution reactions: a functional group replaces a hydrogen atom or another functional group • Alcohols react with hydrogen halides to form alkyl halides • Alkyl halides react with ammonia, NH3, to produce amines • Addition reactions: one bond of a double bond breaks to bond with some other atom • Elimination reactions: to remove certain atoms from a molecule to create a double bond; HCl and HNO2 are often eliminated • Esterification: the reaction of an alcohol with an organic acid to produce an ester • Saponification: a metallic salt of the carboxylic acid is obtained, such as soap, which is a metallic salt of a fatty acid • Polymerization: compounds with double bonds add on to each other to form a polymer Organic Reactions and Biochemistry - C. Chui

3. Petroleum • Petroleum can be separated into portions with different boiling ranges by fractional distillation • Crude oil can be used to manufacture hundreds of products: gases, chemicals, gasoline, naphtha, kerosene, furnace oil, diesel oil, lubricating oil, asphalts, waxes, and coke • Natural rubber is a polymer of 2-methylbutadiene • A low-density organic polymer that conducts electricity better than copper is available in Germany • Gasolines are rated by octane rating. High octane • more ring compounds and highly-branched HC. Tetraethyl lead was used to improve octane rating Organic Reactions and Biochemistry - C. Chui

4. Synthetic Rubber and Plastics • Natural rubber is a polymer of 2-methylbutadiene • Natural rubber and many synthetics are elastomers • Plastics are made by polymerization • Thousands of types of plastics: polyethylene, polypropylene, polyvinyl chloride (PVC), polyvinyl acetate, polystyrene, Teflon, acrylics, etc • Condensation polymerization produces polyesters and polyurethane • Most polymers can be softened by heating, which can forced into molds to make thousands of products Organic Reactions and Biochemistry - C. Chui

5. Synthetic Fibers • Rayon is reconstituted cellulose • Cellulose is a natural polymer of glucose, C6H12O6 • Nylon is the name for a group of polyamide fibers • Nylon-66 can be made from adipic acid (hexanedioic acid) and hexamethylenediamine (1,6-diaminohexane). The amino group of the amine and the carboxyl group of the acid form an amide by condensation Organic Reactions and Biochemistry - C. Chui

6. Proteins • Proteins are polymers made of amino acids • About ½ of proteins are enzymes • Enzymes are catalysts to enable biochemical reactions at body temperatures • Carboxylic acids react with amines to form amides • Amide links are called peptide bonds • Linking 2 amino acids is called a dipeptide; linking 3 amino acidstripeptide, etc • A polypeptide with a biological functionprotein • Proteins differ in the order of amino acids, in the way the chain is folded, or twisted, and in the type of bonds holding the polymer in a particular shape Organic Reactions and Biochemistry - C. Chui

7. Amino Acids • Amino acids are not synthesized in the body • Amino acids come from various food in the diet • 20 left-handed amino acids are found in proteins • Symbols of amino acids: Gly, Ala, Val, Leu, Ile, Trp, Lys, Arg, Phe, His, Asn, Gln, Ser, Thr, Asp, Glu, Tyr, Met, Cys, Pro • In cells, excess energy is used to produce ATP • All organisms, from single-celled algae to humans, use ATP as their energy transfer molecule • Crab shells (chitin) are used as pesticide to kill nematodes, which damage crops in the US Organic Reactions and Biochemistry - C. Chui

8. Carbohydrates • Carbohydrates are simple sugars or polymers of sugars, such as glucose, and fructose • Combining two simple sugars produces a disaccharide • Combining glucose and fructosesucrose • Plants store carbohydrates as starch • Animals store carbohydrates as glycogen • Glycogen, starch, and cellulose differ in the way the monomers are bonded to each other • Carbohydrates break down in the organism to produce H2O, CO2, and energy Organic Reactions and Biochemistry - C. Chui

9. Lipids (Fats) • Proteins and carbohydrates are more soluble in H2O than in nonpolar solvents • Lipids are more soluble in nonpolar solvents than in water • Fats are esters formed from glycerol and fatty acids • Fatty acids are carboxylic acids with 12 to 20 C atoms in the chain • Animals fats are saturated and plant oils are not • Steroids are lipids having a tetracyclic ring system • Cholesterol is found in bile, and in cell membrane • Some vitamins are lipids • Vitamins are substances used by cells to aid enzymatic reactions • Hemoglobin is the red pigment that is an oxygen carrier in humans and some other animals Organic Reactions and Biochemistry - C. Chui

10. Nucleic Acids • Nucleic acids are polymers of nucleotides • Each nucleotide consists of a N-base, a sugar, and a phosphate group • Only 2 sugars are found in nucleic acids: ribose and deoxyribose • 2 nucleic acids: ribonucleic acid (RNA), and deoxyribonucleic acid (DNA) • DNA consists of adenine, cytosine, guanine, and thymine; RNA consists adenine, cytosine, guanine, uracil • DNA is unique for each person: DNA fingerprinting Organic Reactions and Biochemistry - C. Chui

11. Biomaterials • Biomedical engineering have continue to make replacement parts of the body: artificial heart valves, ears, limbs, and organs • Engineers have overcome the rejection problem • Implanted biomaterials can cause blood clots • Researchers are attempting to produce materials by imitating or reusing body materials • Artificial blood vessels are usually made of Dacron or Teflon • Pyrolytic carbon is a biomaterial, a noncrystalline form of carbon • Biomolecular computing is the frontier of research Organic Reactions and Biochemistry - C. Chui