Biology 211 Anatomy & Physiology I

1. Biology 211Anatomy & Physiology I Macromolecules

2. Many molecules in the human body are very large, consisting of hundreds or even thousands of atoms. These are called macromolecules. Four types of macromolecules are particularly important in the human body: P C L N

3. All of these macromolecules are polymers which consist of repeating smaller subunits called monomers Polymer:Monomers Protein Carbohydrate Lipid Nucleic Acid

4. All of these monomers and polymers consist of chains or rings of covalently bonded carbon atoms, with other atoms (primarily hydrogen, oxygen, nitrogen, and phosphorus) attached. Therefore, these are defined as organic molecules. Example: Phospholipid Example: Fatty Acid

5. Rather than draw out these large organic molecules, we typically use a set of shorthand figures for them Amino acids are usually shown as circles Monsaccharides are usually shown as polygons showing the number of carbons Fatty acids are usually shown as wavy lines Nucleotides are usually shown with three parts

8. Polymer:Monomers: Protein Carbohydrate Monosaccharides Lipid Fatty acids & Glycerol Nucleic Acid Nucleotides

9. Proteins form parts of cell membranes enzymes antibodies some hormones molecules which produce movement in muscle fibers in the extracellular matrix ... many other molecules Some proteins exist alone, but many are combined with carbohydrates to form glycoproteins

10. Proteins are composed of unbranching chains of amino acids arranged in different sequences. There are 21-22 different amino acids, all of which have the same basic structure: Where "R" is different for each amino acid

11. Amino Group Carboxyl Group

14. The sequence of amino acids in a protein is called Thus, the proteins Glycine - Alanine - Glutamine - Alanine - Serine and Alanine - Alanine - Glycine - Serine - Glutamine have different structures even though they contain the same amino acids

15. The chain of amino acids in a protein will fold into specific patterns, called Different parts of each chain fold in different ways; Thus, they have different structures

16. This folded protein folds even further to form Since proteins with different primary structures will fold into different secondary structures, they will also fold into different structures

17. These folded proteins may group together, providing the protein with Obviously, proteins with different primary structures will have different secondary structures and thus different tertiary structures which will group into different quaternary structures

19. The specific function of any protein depends on its three-dimensional shape (secondary, tertiary, and quaternary structures) If the shape of the protein is changed, it will no longer function as it should. This is called denaturing the protein

20. Polymer:Monomers: Protein Amino acids Carbohydrate Lipid Fatty acids & Glycerol Nucleic Acid Nucleotides

21. Different monosaccharides have different structures, but all share the same basic formula: Most common monosaccharides: C6 H12 O6 Also found: C3 H6 O3 C4 H8 O4 C5 H10 O5

23. 2 monosaccharides =

24. 2 monosaccharides = 3 monosaccharides = Many monosaccharides = Fuzzy terminology: Monosaccharides Disaccharides = sugars Sometimes: All monosaccharides disaccharides called "sugars" polysaccharides Sometimes: All monosaccharides disaccharides called "carbohydrates" polysaccharides

26. Functions of carbohydrates: 1) Storage of fuel for energy Amylose (starch) in plants Glycogen in animals Human cells can digest amylose but not synthesize it. They can both synthesize & digest glycogen

28. Functions of carbohydrates: 2) Structural carbohydrates Cell walls in plants / bacteria = cellulose & others Exoskeletons of invertebrates = chiton Many in extracellular matrix of all tissues Receptors on cell surfaces (usually bound to proteins or lipids)

29. Polymer:Monomers: Protein Amino acids Carbohydrate Monosaccharides Lipid Nucleic Acid Nucleotides

30. Lipids: Molecules which are hydrophobic and do not mix with water Two major types:

31. Fats & Oils: Monomer (basic repeating units) are bound to a 3-carbon molecule called

32. Fatty acids are long carbon chains (up to 20 or more) with a carboxyl group at one end. If they have no double bonds between carbons, they are called fatty acids

33. If they have one or more double bonds between carbons, they are called fatty acids

34. Glycerol is a 3-carbon molecule: to which fatty acids bond by dehydration synthesis

35. Most common: (2 fatty acids bound to glycerol) (3 fatty acids bound to glycerol)

36. Diglycerides and triglycerides are energy-storage molecules. They can be found in most type of cells, but are primarily found in adipocytes, in which they form large fat droplets in the center. When needed for energy, fatty acids can be released and broken down to release energy to form ATP

37. Related to triglycerides are the , in which one fatty acid is replaced by a phosphate-containing group.

39. Phospholipids are the major component of all cellular membranes Phospholipids are also the surfactant molecules which allow the small air sacs (alveoli) of the lungs to stay open

40. Other type of lipid: Steroids Do not contain glycerol or fatty acids Basic unit = sterol Cholesterol

41. Other steroids include Vitamin D Bile Salts (help absorb fat) Hormones from adrenal gland testes ovaries

42. Polymer:Monomers: Protein Amino acids Carbohydrate Monosaccharides Lipid Fatty acids & Glycerol Nucleic Acid

43. Each nucleotide has three parts:

44. Rribonucleic acid (single chain)

45. Deoxyribonucleic acid (double chain)

46. There are five different base groups in nucleic acids Both DNA & RNA A C G DNA RNA U T