1. Bio 178 Lecture 5 The Chemical Building Blocks of Life (2)

2. Reading Chapter 3 Quiz Material Questions on P 60 Chapter 3 Quiz on Text Website (www.mhhe.com/raven7)

3. Outline Nucleic Acids (Cntd.) Lipids Carbohydrates

4. DNA Structure Double Helix 2 strands joined together that is then twisted into a helical shape. The strands are antiparallel. Outside of Helix Sugar-phosphate backbone. Inside of Helix Nitrogenous bases linked by hydrogen bonds. Only A can pair with T and C with G.

5. DNA Structure What sequence will pair with AGCTTCAG? TCGAAGTC Why will only certain bases pair? Width of helix Hydrogen bonding

6. RNA Structure

7. DNA Versus RNA DNARNA Sugar Type #of Strands Base Types

8. Adenosine Triphosphate ATP

10. Lipids Molecules that are insoluble in water but soluble in oil. 1. Phospholipids Composition 3 subunits: Glycerol 2 fatty acids Phosphate group (this may have an attached charged organic molecule also)

11. Phospholipids are Amphipathic Molecules

12. Lipids 2. Fats Composition 2 subunits - 3 fatty acids and glycerol. Characteristics Lipids that lack a polar component. Functions Energy storage (X 2 starch) Compact Protection Warmth

13. Saturated & Unsaturated Fats

14. Polyunsaturated Fats When a fatty acid has >1 double bond. Atherosclerosis Plaques of fat and cholesterol (amongst other substances) that develop on the internal lining of blood vessels, impeding blood flow).

15. Lipids 3. Terpenes Long-chain lipids that are components of some biologically active pigments. Eg. Chlorophyll.

16. Lipids 4. Steroids Have 4 carbon rings. Eg. Cholesterol, testosterone, estrogen.

18. Carbohydrates Molecules that contain C, H, and O atoms bonded together to form monomers known as monosaccharides. 1. Monosaccharides Example - Glucose C 6 H 12 O 6 Form rings in an aqueous environment Functions in energy storage

19. Glucose

20. Sugar Isomers Isomers - Molecules that have the same empirical formula but different 3D structures. Structural Isomers Eg. Fructose Identical chemical groups bonded to different C atoms. Stereoisomers Eg. Galactose Identical chemical groups bonded to the same C atoms but in different orientations (mirror images).

21. Carbohydrates 2. Disaccharides Example - Sucrose

22. Transport Disaccharides Plants Sucrose - Enzymes for sucrose metabolism only present in the destination tissue  less likely to be metabolized en route than glucose. Animals Lactose - Milk sugar. Adults have reduced quantities of lactase  ensuring that most of the energy from lactose is reserved for the progeny.

23. Carbohydrates 3. Polysaccharides (a) Storage Polysaccharides Plants Polymers of monosaccharides that convert soluble forms of energy into insoluble ones for storage. Starch - Polymers of glucose. 2 types: Amylose - Unbranched. Amylopectin - Branched (short branches). Animals Glycogen - Branched (long branches).

24.  -Glucose OH group on C 1 below the plane of the ring. Eg. Starch  -Glucose OH group on C 1 above the plane of the ring.

25. Polysaccharides (b) Structural Polysaccharides Cellulose Glucose polymer that consists of all  -glucose subunits. Component of plant cell walls. Breakdown requires special enzymes. Chitin Modified form of cellulose with a N group on the glucose subunits. Exoskeleton of arthropods and fungal cell walls.