Figure 3.1 Some Functional Groups Important to Living Systems (Part 1)

1. Figure 3.1 Some Functional Groups Important to Living Systems (Part 1) Class of compounds and an example Functional group Properties Alcohols Polar. Hydrogen bonds with water to help dissolve molecules. Enables linkage to other molecules by dehydration. Hydroxyl Ethanol Aldehydes C==O group is very reactive. Important in building molecules and in energy-releasing reactions. Aldehyde Acetaldehyde Ketones C==O group is important in carbohydrates and in energy reactions. Keto Acetone

2. Figure 3.1 Some Functional Groups Important to Living Systems (Part 2) Class of compounds and an example Functional group Properties Carboxylic acids Acidic. Ionizes in living tissues to form —COO– and H+. Enters into dehydration synthesis by giving up —OH. Some carboxylic acids important in energy-releasing reactions. Carboxyl Acetic acid Amines Basic. Accepts H+ in living tissues to form —NH3 Enters into dehydration synthesis by giving up H+. Amino Methylamine

3. Figure 3.1 Some Functional Groups Important to Living Systems (Part 3) Class of compounds and an example Functional group Properties Organic phosphates Negatively charged. Enters into dehydration synthesis by giving up —OH. When bonded to another phosphate, hydrolysis releases much energy. Phosphate 3-Phosphoglycerate Thiols By giving up H, two —SH groups can react to form a disulfide bridge, thus stabilizing protein structure. Sulfhydryl Mercaptoethanol

4. Butane Isobutane

5. Figure 3.2 Optical Isomers Molecule Mirror image Mirror image Hand Asymmetrical carbon atoms

6. Figure 3.3 Substances Found in Living Tissues Proteins (polypeptides) Macromolecules Nucleic acids Water Carbohydrates (polysaccharides) Ions and small molecules Lipids

7. Figure 3.4 Condensation and Hydrolysis of Polymers Condensation Hydrolysis Monomer

8. Side chain α carbon Amino group Carboxyl group

9. Figure 3.5 A Disulfide Bridge Cysteine molecules in polypeptide chain Side chains

10. Figure 3.6 Formation of Peptide Linkages Amino group Carboxyl group Peptide linkage N terminus (+H3N) C terminus (COO–)

11. Figure 3.7 The Four Levels of Protein Structure (Part 1) Peptide linkage Amino acid monomers Primary structure

12. Figure 3.7 The Four Levels of Protein Structure (Part 2) Hydrogen bond Secondary structure β pleated sheet α helix Hydrogen bond

13. Figure 3.7 The Four Levels of Protein Structure (Part 3) Tertiary structure Quaternary structure β pleated sheet Subunit 1 Subunit 2 Hydrogen bond Disulfide bridge α helix Subunit 3 Subunit 4

14. Figure 3.8 Three Representations of Lysozyme Space-filling model Stick model Ribbon model β pleated sheet β pleated sheet α helix α helix

15. Figure 3.9 Primary Structure Specifies Tertiary Structure (Part 1) Chemically denature functional ribonuclease, disrupting disulfide bridges and other intramolecular interactions that maintain the protein’s shape, so that only primary structure (i.e., the amino acid sequence) remains. Once denaturation is complete, remove the disruptive chemicals. α helix β pleated sheet Disulfide bridge Denatured protein

16. Figure 3.9 Primary Structure Specifies Tertiary Structure (Part 2) When the disruptive agents are removed, three-dimensional structure is restored and the protein once again is functional.

17. Figure 3.10 Quaternary Structure of a Protein α subunits β subunits Heme

18. Figure 3.11 Noncovalent Interactions Between Proteins and Other Molecules Molecule 1 Molecule 2

19. Figure 3.12 Chaperones Protect Proteins from Inappropriate Binding Denatured protein “Lid” HSP60 “cage”

20. Figure 3.13 From One Form of Glucose to the Other Aldehyde group Hydroxyl group α-D-glucose β-D-glucose Straight-chain form Intermediate form

21. Figure 3.14 Monosaccharides Are Simple Sugars Three-carbon sugar Five-carbon sugars (pentoses) Glyceraldehyde Ribose Deoxyribose Six-carbon sugars (hexoses) α-mannose α-galactose Fructose

22. Figure 3.15 Disaccharides Form by Glycosidic Linkages (Part 1) α-1,2 glycosidic linkage Formation of α linkage α-D-glucose Fructose α-D-glucose Fructose Sucrose

23. Figure 3.15 Disaccharides Form by Glycosidic Linkages (Part 2) α-1,4 glycosidic linkage Formation of α linkage α-D-glucose α-D-glucose β-D-glucose β-D-glucose Maltose

24. Figure 3.15 Disaccharides Form by Glycosidic Linkages (Part 3) β-1,4 glycosidic linkage Formation of α linkage β-D-glucose β-D-glucose β-D-glucose β-D-glucose Cellobiose

25. Figure 3.16 Representative Polysaccharides (Part 1) Molecular structure Cellulose Starch and glycogen

26. Figure 3.16 Representative Polysaccharides (Part 2) Macromolecular structure Linear (cellulose) Branched (starch) Highly branched (glycogen) Polysaccharides in cells

27. Figure 3.17 Chemically Modified Carbohydrates (Part 1) Sugar phosphate Phosphate groups Fructose Fructose 1,6 bisphosphate

28. Figure 3.17 Chemically Modified Carbohydrates (Part 2) Amino sugars Glucosamine Galactosamine

29. Figure 3.17 Chemically Modified Carbohydrates (Part 3) N-acetyl group Chitin Glucosamine N-acetylglucosamine Chitin

30. Figure 3.18 Synthesis of a Triglyceride Glycerol (an alcohol) Ester linkage + 3 Fatty acid molecules Triglyceride

31. Figure 3.19 Saturated and Unsaturated Fatty Acids (Part 1) Palmitic acid Oxygen Hydrogen Carbon

32. Figure 3.19 Saturated and Unsaturated Fatty Acids (Part 2) Linoleic acid

33. Figure 3.20 Phospholipids (Part 1) Phosphatidylcholine Positive charge Choline Hydrophilic head Negative charge Phosphate Glycerol Hydrophobic tail Hydrocarbon chains

34. Figure 3.20 Phospholipids (Part 2) Phospholipid bilayer Water Hydrophilic “heads” Hydrophobic fatty acid “tails” Hydrophilic “heads” Water

35. Figure 3.21 -Carotene is the Source of Vitamin A Central double bond -carotene Vitamin A Vitamin A

36. Figure 3.22 All Steroids Have the Same Ring Structure Cholesterol Vitamin D2 Cortisol Testosterone

37. Fatty acid Alcohol Ester linkage