1. 1 Chemistry of Life : Organic Molecules

2. 2 Elements found in living organisms = –Carbon, hydrogen, oxygen, nitrogen, phosphorus, & sulfur Organic Molecules = - contain carbon - made by living things Life is carbon-based : - due to carbon atoms having 4 bonding sites and the ability to form long, complex chains

3. 3 Organic Molecules of Life Organic molecules are put together (synthesized) in a process called polymerization and broken down (hydrolyzed) by all living things in never-ending chemical reactions. Monomers = - building blocks of large organic molecules - like “letters of the alphabet” to make big words Polymers = - large molecules of life made from only a few different monomers - like “big words” that can be created w/ a few letters

4. 4 Organic Molecules of Life (cont.) Synthesis Reactions: Monomers are bonded together to make polymers. Ex. = glucose molecules bonded together to make starch in plants. Ex. = amino acids bonded together to make proteins. Hydrolysis Reactions: Polymers are broken into individual monomers. Ex.= Digestion of starch into glucose molecules in your digestive system. Ex.= Breakdown of fat molecules into small fatty acids when on a diet. monomers polymer monomers polymer

5. 5 http://staff.jccc.net/pdecell/biochemistry/sucrosesyn.gif Polymerization Examples Glucose + Fructose = Sucrose + Water Six monomers linked together to make one polymer and releasing 5 water molecules.

6. 6 Classes of Organic Molecules Molecules of life can be grouped into four classes: 1. Carbohydrates (C,H,O) ex. = sugars, starch, glycogen, cellulose 2. Lipids (C,H,O) ex. = fats, oils, phospholipids, cholesterol 3. Proteins (C,H,N,O,S) ex. = enzymes, hormones, lots of structures! 4. Nucleic Acids (C,H,N,O,P,S) ex. = DNA, RNA

7. 7 1. Carbohydrates Functions = - energy, energy storage, some structural jobs Monomers = monosaccharides (simple sugars) - ex. = glucose, fructose - disaccharides = 2 monomers bonded ex. = sucrose (table sugar) and lactose (milk sugar) Polymers = polysaccharides (many sugars) ex. = starch, glycogen, cellulose, chitin

8. 8 1. Carbohydrates (Cont.) Polysaccharides (Cont.) - starch = energy (glucose) storage in plants - glycogen = energy (glucose) storage in animals - cellulose = makes up plant cell walls (and “wood”) - chitin = makes up fungi cell walls and exoskeleton of crabs, lobsters, insects, etc.

9. 9 2. Lipids Functions = - energy storage, insulation, make up cell membranes Monomers = - 1 glycerol molecule + 3 fatty acid molecules Fats = solid at room temp. ; found in animals ; energy storage ; insulation ; cushioning Oils = liquid at room temp ; energy storage ; mostly in plants

10. 10 2. Lipids (Cont.) Phospholipids = - make up cell membranes - allow materials to enter or exit cells Cholesterol = - found in cell membranes - found in some hormones Waxes = - found mostly in plants - waterproofing Hydrophobic = water fearing Hydrophilic = water loving

11. 11 3. Proteins Monomers = amino acids (a.a.’s) - 20 diff. a.a.’s make up all proteins of life - a.a.’s bonded together w/ peptide bonds Functions of Proteins = - proteins are the structural and functional units of all life!! - each different protein has a different shape and different function Amino acid structure + Peptide bond

12. 12 3. Proteins (Cont.) Enzymes = proteins that act as catalysts - catalyst = molecule that speeds up chemical reactions without being affected by the reaction - each enzyme only works on one specific molecule and does only one specific job - substrate = the molecule an enzyme works on - active site = part of the enzyme molecule where the substrate fits - Induced Fit theory = how enzyme and substrate interact

13. 13 http://www.phschool.com/science/ biology_place/labbench/lab2/induced.html Enzyme Specificity When different substrate molecules are present, only those that have the specific shape complementary to the active site of the enzyme are able to bind with the enzyme. See this animation over again

14. 14 Induced Fit Theory of Enzyme Action When an enzyme binds to the appropriate substrate, subtle changes in the active site occur. This alteration of the active site is known as an induced fit. Release of the products restores the enzyme to its original form. The enzyme can repeat this reaction over and over, as long as substrate molecules are present. See this animation over again

15. 15 4. Nucleic Acids (DNA &RNA) Monomers = nucleotides - nucleotide = nitrogen base, sugar, and a phosphate group (PO4) Functions of Nucleic Acids = - carry and transfer hereditary information