Essential knowledge 4.A.1:

1. Essential knowledge 4.A.1: The subcomponents of biological molecules and their sequence determine the properties of that molecule.

2. Macromolecules Bozeman Biology: https://www.youtube.com/watch?v=PYH63o10iTE&list=PL8GOEDwLwlIOiSrWJuCzUxJ_zMemyYDDZ&index=5 Other macromolecule video: https://www.youtube.com/watch?v=H8WJ2KENlK0&list=PL8GOEDwLwlIOiSrWJuCzUxJ_zMemyYDDZ

3. Structure and function of polymers are derived from the way their monomers are assembled.

4. Polymers • Covalent monomers • Condensation reaction (dehydration reaction): One monomer provides a hydroxyl group while the other provides a hydrogen to form a water molecule • Hydrolysis: bonds between monomers are broken by adding water (digestion)

5. Carbohydrates • MonosaccharidesCH2O formula; √ multiple hydroxyl (-OH) groups and 1 carbonyl (C=O) group: aldehyde (aldoses) sugar ketone sugar √ cellular respiration; √ raw material for amino acids and fatty acids

6. Carbohydrates • Disaccharides glycosidic linkage (covalent bond) between 2 monosaccharides; covalent bond by dehydration reaction • Sucrose (table sugar)most common disaccharide

7. Polysaccharides Energy Storage: Plants: starch (glucose monomers) Animals: glycogen PolysaccharidesStructural in function: Plants: Cellulose Animals:Chitin (found in the exoskeleton of arthropods; also in the cell walls of fungi; Carbohydrates

8. Carbohydrates Summary: • Carbohydrates are composed of sugar monomers whose structures and bonding with each other by dehydration synthesis determine the properties and functions of the molecules. • Illustrative examples include: cellulose versus starch.

9. Lipids • No polymers; glycerol and fatty acid • Fats, phospholipids, steroids • Hydrophobic; H bonds in water exclude fats • Carboxyl group = fatty acid • Non-polar C-H bonds in fatty acid ‘tails’ • Ester linkage: 3 fatty acids to 1 glycerol (dehydration formation) • Triacyglycerol (triglyceride) • Saturated vs. unsaturated fats; single vs. double bonds

10. Phospholipids • 2 fatty acids instead of 3 (phosphate group) • ‘Tails’ hydrophobic; ‘heads’ hydrophilic • Micelle (phospholipid droplet in water) • Bilayer (double layer); cell membranes

11. Steroids • Lipids with 4 fused carbon rings • Ex: cholesterol: cell membranes; precursor for other steroids (sex hormones); atherosclerosis

12. Lipids Summary • In general, lipids are nonpolar; however, phospholipids exhibit structural properties, with polar regions that interact with other polar molecules such as water, and with nonpolar regions where differences in saturation determine the structure and function of lipids.

13. Proteins • Importance: instrumental in nearly everything organisms do; 50% dry weight of cells; most structurally sophisticated molecules known • Monomer: amino acids (there are 20) ~carboxyl (-COOH) group, amino group (NH2), H atom, variable group (R)…. • Variable group characteristics: polar (hydrophilic), nonpolar (hydrophobic), acid or base • Three-dimensional shape (conformation) • Polypeptides (dehydration reaction): peptide bonds~ covalent bond; carboxyl group to amino group (polar)

14. Protein Structure • Primary • Secondary • Tertiary • Quaternary

15. Primary Structure • Conformation: Linear structure • Molecular Biology: each type of protein has a unique primary structure of amino acids • Ex:lysozyme • Amino acid substitution: hemoglobin; sickle-cell anemia

16. Secondary Structure • Conformation: coils & folds (hydrogen bonds) • Alpha Helix: coiling; keratin • Pleated Sheet: parallel; silk

17. Tertiary Structure • Conformation: irregular contortions from R group bonding √hydrophobic √disulfide bridges √hydrogen bonds √ionic bonds

18. Quaternary Structure • Conformation: 2 or more polypeptide chains aggregated into 1 macromolecule • Ex: collagen (connective tissue) • hemoglobin

19. Types of Proteins • Structural Protein • Storage Proteins • Transport Proteins • Receptor Proteins • Contractile • Defensive • Enzymes • Signal • Sensory • Gene Regulator

20. Protein Summary • In proteins, the specific order of amino acids in a polypeptide (primary structure) interacts with the environment to determine the overall shape of the protein, which also involves secondary tertiary and quaternary structure and, thus, its function. • The R group of an amino acid can be categorized by chemical properties (hydrophobic, hydrophilic and ionic), and the interactions of these R groups determine structure and function of that region of the protein.

21. Nucleic Acids, I • Deoxyribonucleic acid (DNA) • Ribonucleic acid (RNA) • DNA->RNA->protein • Polymers of nucleotides (polynucleotide):nitrogenous base pentose sugar phosphate group • Nitrogenous bases: pyrimidines~cytosine, thymine, uracilpurines~adenine, guanine

22. Nucleic Acids • Pentoses: √ribose (RNA) √deoxyribose (DNA) √nucleoside(base + sugar) • Polynucleotide: √phosphodiester linkages (covalent); phosphate + sugar

23. Nucleic Acids • Inheritance based on DNA replication • Double helix (Watson & Crick - 1953) H bonds~ between paired bases van der Waals~ between stacked bases • A to T; C to G pairing • Complementary

24. Nucleic Acids Summary • In nucleic acids, biological information is encoded in sequences of nucleotide monomers. Each nucleotide has structural components: • a five-carbon sugar (deoxyribose or ribose), a phosphate and a nitrogen base (adenine, thymine, guanine, cytosine or uracil). • DNA and RNA differ in function and differ slightly in structure, and these structural differences account for the differing functions.

25. Directionality influences structure and function of the polymer. Examples are found in DNA, Proteins and Carbohydrates on the following slides.

26. DNA • 1. Nucleic acids have ends, defined by the 3' and 5' carbons of the sugar in the nucleotide, that determine the direction in which complementary nucleotides are added during DNA synthesis and the direction in which transcription occurs (from 5' to 3'). • http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120076/bio23.swf::How%20Nucleotides%20are%20Added%20in%20DNA%20Replication

27. Proteins • 2. Proteins have an amino (NH2) end and a carboxyl (COOH) end, and consist of a linear sequence of amino acids connected by the formation of peptide bonds by dehydration synthesis between the amino and carboxyl groups of adjacent monomers.

28. Carbohydrates • 3. The nature of the bonding between carbohydrate subunits determines their relative orientation in the carbohydrate, which then determines the secondary structure of the carbohydrate.