1. 6.3 Life Substances Molecules of Life

2. Role of Carbon in Organisms Carbon has four electrons in outer energy level Four covalent bonds fill energy level

3. Role of Carbon in Organisms Carbon can bond with other carbon atoms Double bond = each atom shares two electrons Triple bond = each atom shares three electrons

4. Role of Carbon in Organisms When carbon atoms bond together they can form chains, branched chains or rings This makes a huge number of carbon structures possible

5. Role of Carbon in Organisms Compounds with the same simple structure can have different forms called isomers

6. Role of Carbon in Organisms Carbon compounds can have thousands of carbons Polymer = a large molecule formed when many smaller molecules bond together Condensation = large molecule is formed by removing H-O-H Hydrolysis = large molecule is broken apart by adding H-O-H

7. Role of Carbon in Organisms

8. Carbohydrates Used by cells to store and release energy Organic compound with carbon, hydrogen 2, and oxygen Simple carbohydrate = monosaccharide Two sugar carbohydrate = disaccharide Many sugars = polysaccharide

9. Carbohydrates

10. Molecules of Life Carbohydrates Lipids Proteins Nucleic Acids

11. Lipids Used by cells to store energy, insulate and in protective coatings Organic compound with many more carbon and hydrogen than carbohydrates For example, beef fat C 57 H 110 O 6 Not soluble in water because lipids are non-polar

12. Lipids 2 main types Each made of 3 fatty acids and a glycerol Saturated—bad for you (butter) Unsaturated—good for you (peanut butter)

13. Lipids

14. Proteins Provide structure and carry out cell metabolism Large polymer built of amino acids Carbon, hydrogen, oxygen, nitrogen, sulfur There are 20 common amino acids that can build thousands of proteins

15. Proteins Amino acids link together in peptide bonds Number and order of amino acids determines the kind of protein

16. Proteins Contract muscle tissue Transport oxygen in bloodstream Provide immunity Carry out chemical reactions Enzyme = protein that changes the rate of a chemical reaction

17. Nucleic Acids Stores cellular information in code Made up of nucleotides Carbon, hydrogen, oxygen, nitrogen phosphorus Arranged in a base, a sugar, and a phosphate group

18. Nucleic Acids DNA = Deoxyribonucleic acid Contains instructions on how to make enzymes and proteins Genetic code for how an organism looks Passed from one generation to the next

19. Nucleic Acids - DNA

20. Nucleic Acids RNA = ribonucleic acid Makes copies of DNA for use in making proteins