1. MOLECULES OF LIFE CH5 All living things are made up of 4 classes of large biomolecules: o Proteins o Carbohydrates o Lipids o Nucleic acids Molecular structure and biological function are intricately related

2. I. Macromolecules Large molecules made of thousands of atoms covalently bonded 3 of the 4 biomolecules are polymers: proteins, carbs, nucleic acids Polymer: a macromolecules made of repeating units called monomers

3. The Synthesis and Breakdown of Macromolecules Macromolecules are made by dehydration reactions Macromolecules are broken down by hydrolysis reactions

4. II. Carbohydrates Sugars and the polymers of carbohydrates o Monosaccharides o Disaccharides o polysaccharides

5. A. Monosaccharides (CH 2 O) structure o A single sugar ex: glucose o Classified by number of carbons in chain and location of carbonyl

6. function o Quick energy source o Immediately enters into cellular respiration for production of ATP

7. Most monosaccharides exist as a ring

8. isomers o Molecules with same structural formula but different arrangement of atoms o Ex: glucose, fructose, and galactose

9. B. Disaccharides Structure o 2 monosaccharides linked via dehydration reactions o EX: sucrose, lactose Function Energy

10. C. Polysaccharides Long chain of GLUCOSE molecules linked via dehydration reactions 2 groups of polysaccharides o Storage: starch and glycogen o Structural: cellulose chitin

11. 1. Storage polysaccharides Glycogen – Stores glucose in animals – Many glucose molecules linked via α1-4 linkages Starch – Stores glucose in plants – Many glucoses linked by α1-4 linkages – http://bcs.whfreeman.com/thelifewire/conte nt/chp03/0302002.html http://bcs.whfreeman.com/thelifewire/conte nt/chp03/0302002.html

12. 2. structural polysaccharides cellulose o forms cell wall in plants o many glucoses linked via β1-4 linkages chitin o forms exoskeleton in arthropods and cell wall in fungi

14. Most animals have enzymes to break α1-4 linkage but not β1-4 linkage. Most cellulose consumed exits as insoluble fiber Only some bacteria have enzymes to break β1-4 linkage

15. III. Lipids Diverse group of hydrophobic molecules Only macromolecule that doesn’t form polymer

16. A. Triglycerides (fats and oils) One glycerol + 3 fatty acids linked via dehydration reactions http://www2.nl.edu/jste/bioch em.htm

17. Fatty Acid Long chain of C and H with a carboxyl group Usually 14 to 20 Cs Fatty acids can be – Saturated: no carbon to carbon double bonds. Solid at room temp – Monounsaturated: 1 carbon to carbon double bond. Liquid at room temp – Polyunsaturated: more than 1 carbon to carbon double bond. Liquid at room temp

19. – Function of triglycerides Long term energy storage Seeds use stored triglycerides as energy during germination Insulation in mammals http://bcs.whfreeman.com/thelifewire/ content/chp03/0302002.html http://bcs.whfreeman.com/thelifewire/ content/chp03/0302002.html

20. B. Phospholipids Structure o One glycerol + 2 fatty acids + 1 phosphate head

21. Property o Amphiphathic: polar charged phosphate head and nonpolar uncharged fatty acid tails Function: o Make up phospholipid bilayer found in all biological membranes

23. C. Waxes and Steroids Waxes – Function as protective barrier Steroids – Function as chemical messengers

24. IV. Proteins About 50% of all macromolecules are proteins

25. A. Functions of Proteins

27. Polypeptide: long chain of amino acids Protein: biologically functional molecule made of 1 or more polypeptides

28. B. Amino Acids: monomer of proteins general structure o all contain amino and carboxyl group but differ in their R group

29. Groups of amino acids: based on the characteristics of R group

30. Linking of amino acids Link to form peptide bond by dehydration reaction Amino end of incoming amino acid links to carboxyl end of growing chain Each polypeptide has a unique order of amino acids

31. http://www2.nl.edu/jste/biochem.htm http://bcs.whfreeman.com/thelifewire/conte nt/chp03/0302002.html

32. Protein Structure Protein structure is determined by the sequence of amino acids Structure determines its function As protein is being synthesized, it begins to fold into its correct shape Proteins fold as a result of the interactions between amino acids in the polypeptide chain http://www.ncbi.nlm.nih.gov/sites/entrez?db =structure http://www.ncbi.nlm.nih.gov/sites/entrez?db =structure

33. There are 4 levels of protein structure primary structure

34. number and order of amino acids in the protein chain primary structure is determined by______________ all proteins have a different primary structure

35. secondary structure – Hydrogen bonding between amino and carboxyl groups – 2 forms: α helix and β sheet

37. Tertiary structure – Interaction among the R groups of amino acids – Interactions include ionic bonds, hydrogen bonds, hydrophobic interactions, and covalent bonds – What type of amino acids involved in each?

39. Quaternary structure 2 or more polypeptide chains associated together to form a functional protein

40. In a cell, special proteins called chaperonins help proteins fold into their shape http://parasol- www.cs.tamu.edu/groups/amatogroup/resea rch/folding/proteinA.php http://parasol- www.cs.tamu.edu/groups/amatogroup/resea rch/folding/proteinA.php

42. D. Protein unfolding Denaturation: unfolding of a protein as a result of changes in pH and temp

43. V. Nucleic Acids The information molecules: contain the code to make proteins

44. Structure – Long chains of nucleotides Nucleotides – Made of a: 5 carbon sugar Phosphate group One of 4 bases Function – DNA: stores hereditary info – RNA: expresses it