The Chemistry of Life

1. The Chemistry of Life Chapter 2

2. Water • Water makes up approx 70 to 95 percent of most organisms. • When the electrons in a covalent bond are not shared equally they form a polar molecule. • Polar Molecule: unequal distribution of charge, the molecule has a distinct partial positive end and a partial negative end. Universal Solvent: “like dissolves like”

3. H20 - Polar molecule Hydrogen 1p+ S- S- Hydrogen 1p+ 2e- 6e- 8p+ 8n0 S+ S+ S+ S+ Oxygen

4. Water - Polarity

5. http://www.youtube.com/watch?v=DAilC0sjvy0&feature=related Water • Properties • High Specific Heat – resists changes in temp. • Water retains its state at temperature levels where other liquids would begin to turn into gas or evaporate. • Cohesion – attraction of water molecules, • provides surface tension. • Adhesion – attraction of water to different substances….meniscus

6. Role of Carbon • Carbon has 4 electrons to share and it can share these electrons in three different ways. • 4 Covalent bonds it can form • 1. Single C - C • 2. Double C = C • 3. Triple C C

7. Carbon-based molecules have three general types of structures. • Straight • Branched • Ring

8. ISOMERS • Isomers - compounds that have the same molecular formula but different structural formula.

9. Monomer - singular unit or molecule • Polymer - a group of molecules or units bonded together. cellulose

11. FUNCTIONAL GROUPS • Most organic compounds have functional groups of atoms that carry out chemical reactions. • FUNCTIONAL GROUPS • -NH2 Amine Proteins • -PO4 Phosphate Nucleic Acids • -COOH Carboxylic Acid Fats • -OH Hydroxyl or Lipids & Alcohol Carbohydrates

12. ENDINGS • -ose Sugars (Sucrose) • -in Proteins (Pepsin) • -ase Protein Enzyme (Amylase) • -ol Lipid (Glycerol)

13. CARBOHYDRATES • - C, H, O • 1 Carbon : 2 Hydrogens : 1 Oxygen • 1:2:1 ratio • Example: • Glucose C6H12O6

14. CARBOHYDRATE MONOMERS • Monosaccharides - simplest carbohydrate • Most common arrangement : C6H12O6 • Names : Glucose, Fructose, Galactose

15. CARBOHYDRATE POLYMERS • Disaccharides - 2 monosaccharides covalently bonded together. • Glucose + Galactose = Lactose (milk sugar) • Glucose + Fructose = Sucrose (table sugar) • Glucose + Glucose = Maltose (malt sugar)

16. Disaccharides

17. CARBOHYDRATE POLYMERS • Polysaccharides - long chains (polymers) • Glycogen- made and stored in animals …highly branched compared to plant starches (store food in the liver as glycogen) • Starch – is made and stored by plants (potatoes) • Cellulose – straight rigid structure that makes up the cell wall in plants (celery, cotton) • Chitin – rigid structure that makes up exoskeleton of insects

18. Polysaccharides

20. Processes of Forming and Breaking Bonds • 1) Dehydration Synthesis/Condensation - put monomers together by removing water (H2O) • 2) Hydrolysis - Add H20 to break covalent bonds http://nhscience.lonestar.edu/biol/dehydrat/dehydrat.html

21. Dehydration Synthesis Hydrolysis

22. LIPIDS • - C, H, O • Fats, oils, waxes, cholesterol (steroids), phospholipids (C57H110O6) • Nonpolar - insoluble in water, make up cell membrane, energy, used to make hormones, and Elle’s love for *all* her students. • Fat = 3 Fatty acids + glycerol (monomers) • Fatty acid : 1. Chain of C and H atoms 2. Carboxyl group -COOH • Glycerol : 3 Carbon molecule, backbone of a lipid. (polymer)

23. LIPID carboxyl http://users.uma.maine.edu/SusanBaker/triglyceride.html Triglyceride

24. Phospholipid 1. Glycerol 2. 2 fatty acids 3. Phosphate head

25. Steroids Cholesterol

26. 2 KINDS OF FATS • 1. Saturated Fats - single carbon bonds (solids) • 2. Unsaturated Fats - double or triple carbon bonds (liquids)

27. PROTEINS • -N, C, H, O sometime S, and always love • made up of amino acids (monomers/basic building blocks of a protein) 1 amino group (-NH2) 1 side chain (R) 1 Carboxyl group

28. Amino acids differ in side groups, or R groups.

29. PROTEINS • PEPTIDE BONDS : bonds formed between the amino group of one amino acid and the carboxyl group of another, with love. • What process allows peptide bonds to take place? H R H R H - N - C - C - OH + H - N - C - C - OH H O H O Dehydration Synthesis

30. hydrogen bond Hemoglobin • Amino acids interact to give a protein its shape. • Proteins differ in the number and order of amino acids. • Incorrect amino acids change a protein’s structure and function.

31. PROTEINS • Polypeptides : proteins, long chains of amino acids • 20 different amino acids

32. NUCLEIC ACIDS • P, N, C, H, O • Hereditary Material • 1. DNA - 2 chains - deoxyribose sugar - phosphate backbone - nitrogeneous base • 2. RNA - 1 chain - ribose sugar - phosphate backbone - nitrogeneous base

33. NUCLEIC ACIDS • Nucleotides : monomer of a nucleic acid. • Nucleotides are composed of 3 separate parts • 5 Carbon + PO4 + Nitrogen Base Sugar Phosphate Group S N P Nucleotide

34. nitrogen-containing molecule,called a base A phosphate group deoxyribose (sugar) • Nucleic acids are polymers of monomers called nucleotides. • Nucleotides are made of a sugar, phosphate group, and a nitrogen base.

35. DNA Nucleotides

36. DNA Nucleotides

37. ATP Nucleotide

38. NUCLEIC ACIDS • Nitrogen Bases adenine (purine) guanine (purine) cytosine (pyrimidine) thymine (pyrimidine) uracil (pyrimidine) *Only in DNA *Only in RNA

39. ENZYMES • Protein catalysts necessary for most of the chemical rxns that occur in living cells. • Catalysts : a substance that increase the rate of a chemical rxn.

40. HOW DO YOU RECOGNIZE AN ENZYME? • *Enzymes are usually named after the substrate with an -ase ending. • Substrate : the substance an enzyme acts upon • EXAMPLES : • Enzyme that splits maltose into 2 glucose molecules is maltase • Proteins - Protease • Lipids - Lipase

41. HOW DO ENZYMES WORK? 1. The enzyme shape makes it able to do work. Active Site Enzyme 2. The active site is the place on the enzyme where the rxn occurs. 3. The substance the enzyme act upon is the substrate maltose * The active site must fit the shape of the substrate

42. HOW DO ENZYMES WORK? 4. The substrate and the active site of the enzyme come together briefly to form the enzyme - substrate complex. Enzyme *While temporarily together the enzyme may make or break bonds within the substrate. OH OH * Note enzymes are not changed by the rxn Enzyme

43. QUESTION ? * What enzyme broke the bond between the disaccharide maltose in the previous slide? Maltase

44. HYPOTHESIS FOR HOW AN ENZYME WORKS (2) • 1. Lock & Key Hypothesis: • Proposes that the substrate fits exactly into the active site on the enzyme. • * Key - Active Site unlocks the lock - substrate • 2. Induced Fit Hypothesis : • Proposes that the enzyme changes shape slightly to grasp the substrate at the active site. • * Hand grasping a baseball (molds to shape of object)

46. http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.htmlhttp://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__enzyme_action_and_the_hydrolysis_of_sucrose.html

47. Diffusion • Diffusion : the net movement of particles from an area of higher concentration to an area of lower concentration. Key factors in the rate of diffusion: concentration, temperature, and pressure.

48. What is Equilibrium? • Equilibrium : when concentrations are equal and the net movement of particles is equal.