2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Organic and Biochemical Compounds Objectives Describe how carbon atoms bond covalently to form organic compounds. Identify the names and structures of groups of simple organic compounds and polymers. Identify what makes up the polymers that are essential to life. Chapter 5

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Organic and Biochemical Compounds Organic Compounds In chemistry, the word organic is used to describe certain compounds. An organic compound is a covalently bonded compound that contains carbon, excluding carbonates and oxides. Many ingredients of familiar substances contain carbon. Chapter 5

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Organic Compound Section 4 Organic and Biochemical Compounds Chapter 5

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Organic and Biochemical Compounds Organic Compounds, continued Carbon atoms form four covalent bonds in organic compounds. When a compound is made of only carbon and hydrogen atoms, it is called a hydrocarbon. Alkanes are hydrocarbons that have only single covalent bonds. Examples: Chapter 5

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Hydrocarbon Section 4 Organic and Biochemical Compounds Chapter 5

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Alkane Section 4 Organic and Biochemical Compounds Chapter 5

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Organic and Biochemical Compounds Organic Compounds, continued The carbon atoms in any alkane with more than three carbon atoms can have more than one possible arrangement. Carbon atom chains may be branched or unbranched, and they can even form rings. Except for cyclic alkanes, the chemical formulas for alkanes follow a special pattern. The number of hydrogen atoms is always two more than twice the number of carbon atoms. Chapter 5

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Six-Carbon Alkanes Section 4 Organic and Biochemical Compounds Chapter 5

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Organic and Biochemical Compounds Organic Compounds, continued Alkenes are hydrocarbons that contain double carbon-carbon bonds. Example: ethene, Chapter 5 Alcohols have hydroxyl, or –OH, groups. Example: methanol, CH 3 OH Alcohol molecules behave similarly to water molecules. Alcohols, which have the suffix -ol in their names, are found in many household products.

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Alkene Section 4 Organic and Biochemical Compounds Chapter 5

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Alcohol Section 4 Organic and Biochemical Compounds Chapter 5

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Organic and Biochemical Compounds Polymers A polymer is large molecule that is formed by more than five monomers, or small units. Example: polyethene (often known as polyethylene) is a long chain made from many molecules of ethene. Some polymers are natural; others are man-made. Examples: rubber, starch, protein, and DNA are all natural polymers. Plastics and synthetic fibers are man-made polymers. Chapter 5

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Polymers Section 4 Organic and Biochemical Compounds Chapter 5

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Organic and Biochemical Compounds Polymers, continued The elasticity of a polymer is determined by its structure. Examples: A milk jug made of polyethene is not elastic: it can be crushed, but does not return to its original shape. A rubber band is an elastic polymer: when it is stretched and released, it returns to its original shape. Chapter 5

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Comparing Polymer Structures Section 4 Organic and Biochemical Compounds Chapter 5

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Organic and Biochemical Compounds Biochemical Compounds A carbohydate is any organic compound that is made of carbon, hydrogen, and oxygen and that provides nutrients to the cells of living things. A protein is an organic compound that is a polymer of amino acids, and a principal component of all cells. An amino acid is any one of 20 different organic molecules that contain a carboxyl and an amino group. Chapter 5

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Proteins Section 4 Organic and Biochemical Compounds Chapter 5

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 4 Organic and Biochemical Compounds Biochemical Compounds, continued Your DNA determines your entire genetic makeup. DNA is a polymer with a complex structure. It is in the form of paired strands, in the shape of a twisted ladder known as a double helix. Each time a new cell is made in your body, a new copy of your DNA is made for the new cell. The two strands in the helix are separated each time your DNA is copied. Chapter 5

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu DNA Overview Section 4 Organic and Biochemical Compounds Chapter 5

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Concept Mapping Section 4 Organic and Biochemical Compounds Chapter 5