2. To continue

5. Recall: In our study of biology We are considering what I call: LIVING SYSTEMS Highly organized systems of Matter and Energy

6. In our discussions then, we must Consider the relation of CHEMISTRY to the patterns and processes of LIVING SYSTEMS

7. The processes of chemisty are actually rather straightforward…

8. Here is chemistry in action!

9. But…what have we here?

10. We will end the semester with this, the Universe’s most complex chemical structure, and the “secret of life.” It’s DNA

11. But the chemistry of a l.s. requires us to consider certain ELEMENTS and their Chemical interactions

12. Here are most of the elements!

13. But a l.s. does not concern itself with every one of the approximately 90 naturally occurring elements…

14. Not this one…

15. This one…

16. Carbon, ol’ #6, is the “element of life,” and life is based on the Chemistry of Carbon

17. So why IS CARBON and its chemistry the basis of Living Systems?

18. But, then, what is chemistry?

19. Let’s pause a moment and ask a question…

20. The Purpose of Life is: a. to use matter and energy b. to survive and reproduce c. to understand the Universe d. to use chemical reactions

21. The Purpose of Life is: a. to use matter and energy b. to survive and reproduce c. to understand the Universe d. to use chemical reactions

22. But what was that we were saying about CHEMISTRY?

24. We are talking about SPONCH and the “Big C”

25. I’m a Woodchuck, and I’m full of SPONCH!

26. SPONCH? The major ELEMENTS found In Living Systems: Sulfur, Phosphorus, Oxygen Nitrogen, Carbon, Hydrogen

27. In order of abundance: Hydrogen Oxygen (A lot of H 2 O in a l.s.) Carbon Nitrogen Phosphorus Sulfur

28. SPONCH and some pals in a l.s.

29. Quick tour of Chemistry…

30. You know all about this, don’t you?

31. ISOTOPES—we’ll meet some of these later. Distinguish from ISOMERS, which we’ll meet today.

32. Although there is only a handful of different kinds of ELEMENTS in a living system, There are millions of kinds of MOLECULES

33. Let’s go from ATOMS to MOLECULES via a CHEMICAL REACTION

34. This one

36. Hydrogen plus oxygen…

38. What’s that “Delta G” thingy? It’s the “energy part” of a chemical reaction

39. A Chemical Reaction Involves the Making or Breaking of bonds, which are Electron Relations Between atoms

41. A Bond

42. Those bonds were COVALENT BONDS, (shared pairs of electrons) but there are other kinds of bonds that we can see in some molecules. In particular, Water illustrates the kind of bond called a HYDROGEN BOND

46. And water is also involved in the chemical condition that we call pH

48. Let’s pause for a moment…

49. A molecule is two or more atoms held together by a/an: a. exergonic relation b. chemical bond c. nuclear reaction d. elemental action

50. A molecule is two or more atoms held together by a/an: a. exergonic relation b. chemical bond c. nuclear reaction d. elemental action

51. When we look at living systems, from atom to organism, we can view it in terms of Levels of Structure

53. NIBMSEITLOE… Life has evolved chemically, as well as structurally, and all the chemical evolution is based on the chemistry of Carbon Molecules

56. Carbon molecules doing living things!

57. This is a fossil leaf, and the dark material

58. Is the carbon that made up its organic molecules…

59. The key element is Carbon

60. CARBON, Hooray!

61. Elemental Carbon as SOOT

62. Elemental Carbon As GRAPHITE

63. Elemental Carbon as DIAMOND

64. But we are interested in CARBON Which is in the form of ORGANIC MOLECULES

66. Here is a collection of a Variety of both Inorganic and Organic Molecules

68. And how do we build the thousands of different organic molecules that we find in any living system?

70. I call it “building the Chemical Cathedral”

74. But METABOLISM consists of TWO parts: ANABOLISM—the “building up” of large molecules from smaller ones. But also there is CATABOLISM, the breakdown of larger molecules into smaller ones.

75. The breakdown process…

76. Hydrolysis is DOWNHILL towards less structure, and the Universe favors processes like this over those in the direction of more structure

81. Let’s begin to look at building up and breaking down in relation to one of our classes of Organic Molecules, CARBOHYDRATES

82. The Basic Carbohydrate (for our purposes) Is a hexose, A monosaccharide, A simple sugar… GLUCOSE

85. But subtle differences in structure (ISOMERS) can produce sugars of different types

88. And there are other kinds of Sugars than Hexoses [6C] We can find: Trioses [3C] Pentoses [5C]

90. Let’s do a little “Cathedral Building”

92. We call this dehydration synthesis

93. So why IS CARBON and its chemistry the basis of Living Systems?

94. But, then, what is chemistry?

95. The Purpose of Life is: a. to use matter and energy b. to survive and reproduce c. to understand the Universe d. to use chemical reactions

96. The Purpose of Life is: a. to use matter and energy b. to survive and reproduce c. to understand the Universe d. to use chemical reactions

97. To be continued…