1. Organic Compounds

2. Organic Compounds
The big four are
carbohydrates

3. Organic Compounds
The big four are
Carbohydrates
lipids

4. Organic Compounds
The big four are
Carbohydrates
Lipids
proteins

5. Organic Compounds The big four are Carbohydrates Lipids Proteins
Nucleic acids

6. Organic Compounds
Each has a specific role within a cell

7. Organic Compounds Each has a specific role within a cell
They all have in common two reactions which are used to form them or break them down. These are the dehydration synthesis reaction and hydrolysis reactions.

8. + (a) Dehydration synthesis
Monomers are joined by removal of OH from one monomer
and removal of H from the other at the site of bond formation. +
Monomer 1
Monomer 2
Monomers linked by covalent
bond

9. (b) Hydrolysis
Monomers are released by the addition of a water molecule,
adding OH to one monomer and H to the other.
Monomer 1 +
Monomer 2
Monomers linked by covalent bond

10. Organic Compounds
Carbohydrates include sugars and starches and are classified into 3 groups depending on the number of sugars.

11. Organic Compounds
Carbohydrates include sugars and starches and are classified into 3 groups depending on the number of sugars.
These are monosaccharides, diassacharides and polysaccharides

12. Organic Compounds Monosaccharides
Most common example is glucose but there are many structural isomers, for example, Fructose and Galactose

13. Organic Compounds Monosaccharides
Most common example is glucose but there are many structural isomers, for example, Fructose and Galactose
These all share a formula of C6H12O6

14. Organic Compounds
Monosaccharides are used as building blocks for more complex carbohydrates and for cell respiration and formation of ATP.

15. Organic Compounds

16. Organic Compounds
Disaccharides are double sugars and are formed from two monosaccharides.

17. Organic Compounds
Disaccharides are double sugars and are formed from two monosaccharides.
Common disaccharides are:
sucrose

18. Organic Compounds
Disaccharides are double sugars and are formed from two monosaccharides.
Common disaccharides are:
sucrose
lactose

19. Organic Compounds
Disaccharides are double sugars and are formed from two monosaccharides.
Common disaccharides are:
sucrose
lactose &
maltose

20. (b) Disaccharides
Consist of two linked monosaccharides
Example
Sucrose, maltose, and lactose
(these disaccharides are isomers)
Glucose
Fructose
Glucose
Glucose
Galactose
Glucose
Sucrose
Maltose
Lactose

21. Organic Compounds
Disaccharides are too large to pass through cell membranes and are broken sown by hydrolysis reactions to monosaccharides.

22. Organic Compounds
Polysaccharides are polymers of simple sugars.

23. Organic Compounds Polysaccharides are polymers of simple sugars.
They are large insoluble molecules and are used for storage of excess carbohydrates or as part of a complex cell membrane molecule.

24. (c) Polysaccharides
Long branching chains (polymers) of linked monosaccharides
Example
This polysaccharide is a simplified representation of
glycogen, a polysaccharide formed from glucose units.
Glycogen

25. Organic Compounds
Glycogen is a common storage carbohydrate found in the liver and muscle tissue.
Glycoproteins are combinations of proteins and sugars. They make up a portion of the surface of the cell membrane and often serve as receptors.

26. Organic Compounds

27. Organic Compounds
Lipids are nonpolar molecules and are insoluble in water.
There are several classes of lipids:
Triglycerides

28. Organic Compounds
Lipids are nonpolar molecules and are insoluble in water.
There are several classes of lipids:
Triglycerides
Phospholipids

29. Organic Compounds
Lipids are nonpolar molecules and are insoluble in water.
There are several classes of lipids:
Triglycerides
Phospholipids
steroids

30. Organic Compounds
Triglycerides are neutral fats and are composed of fatty acids and glycerol.

31. Organic Compounds
Triglycerides are found primarily beneath the skin and serve as insulation and long term energy storage.

32. Triglyceride, or neutral fat 3 water molecules
(a) Triglyceride formation
Three fatty acid chains are bound to glycerol by
dehydration synthesis +
Glycerol
3 fatty acid chains
Triglyceride,
or neutral fat
3 water
molecules

33. (b) “Typical” structure of a phospholipid molecule
Two fatty acid chains and a phosphorus-containing group are
attached to the glycerol backbone.
Example
Phosphatidylcholine
Polar
“head”
Nonpolar
“tail”
(schematic
phospholipid)
Phosphorus-
containing
group (polar
“head”)
Glycerol
backbone
2 fatty acid chains
(nonpolar “tail”)

34. Organic Compounds
Phospholipids are modified triglycerides and make up an important part of the cell membrane.

35. Organic Compounds
The fatty acids that make up a triglyceride or phospholipid can be classified as saturated or unsaturated.

36. Organic Compounds
The fatty acids that make up a triglyceride or phospholipid can be classified as saturated or unsaturated.
Fatty acids also vary in length and are usually 14 to 20 carbons in length.

37. Organic Compounds
Saturated fatty acids have only single covalent bonds and can pack closely together..

38. Organic Compounds
Unsaturated fatty acids have one or more double covalent bonds and do not pack closely together.

39. Organic Compounds
Trans fatty acids are unsaturated fatty acids that have had some of the double bonds converted to single covalent bonds. Problem, we don't have enzymes to break them down.

40. Organic Compounds
Steroids are structurally not related to the other lipids but are classified as such because they are nonpolar. Most common is cholesterol.

41. Four interlocking hydrocarbon rings form a steroid.
Example
Cholesterol (cholesterol is the
basis for all steroids formed in the body)

42. Organic Compounds
Proteins make up 10 to 30 % of the body’s mass. They play many roles in the cell including:
Structural

43. Organic Compounds
Proteins make up 10 to 30 % of the body’s mass. They play many roles in the cell including:
Structural
Enzymes

44. Organic Compounds
Proteins make up 10 to 30 % of the body’s mass. They play many roles in the cell including:
Structural
Enzymes
Hormones

45. Organic Compounds
Proteins are made up of 20 amino acids. Each amino acid has unique properties and when linked together with other amino acids, forms a unique protein.

46. Amine
group
Acid
group
(a) Generalized
structure of all
amino acids.
(b) Glycine is the simplest
amino acid.
(c) Aspartic acid
(an acidic amino acid)
has an acid group
(—COOH) in the
R group.
(d) Lysine
(a basic amino acid)
has an amine group
(–NH2) in the R group.
(e) Cysteine
(a basic amino acid)
has a sulfhydryl (–SH)
group in the R group,
which suggests that
this amino acid is likely
to participate in
intramolecular bonding.

47. Organic Compounds
Proteins are joined or broken down by hydrolysis or dehydration synthesis reactions

48. + Dehydration synthesis: The acid group of one amino acid is bonded to
the amine group of the
next, with loss of a water
molecule.
Peptide
bond +
Amino acid
Amino acid
Dipeptide
Hydrolysis: Peptide
bonds linking amino
acids together are
broken when water is
added to the bond.

49. Organic Compounds
Proteins can be described in terms of four structural levels.
Primary Structure is the amino acid sequence

50. Levels of protein structure.
Amino acid
Amino acid
Amino acid
Amino acid
Amino acid
Primary structure:
The sequence of amino acids forms the polypeptide chain.

51. Organic Compounds
Proteins can be described in terms of four structural levels. 2. Secondary Structure is brought about by hydrogen bonds between neighboring amino and carboxylic acid groups.

52. Organic Compounds
Proteins can be described in terms of four structural levels. 2. Secondary Structure is brought about by hydrogen bonds between neighboring amino and carboxylic acid groups. Two forms can exist, the alpha Helix and the Beta sheet.

53. Levels of protein structure.
a-Helix: The primary chain is coiled
to form a spiral structure, which is
stabilized by hydrogen bonds.
b-Sheet: The primary chain “zig-zags” back
and forth forming a “pleated” sheet. Adjacent
strands are held together by hydrogen bonds.
(b) Secondary structure:
The primary chain forms spirals (a-helices) and sheets (b-sheets).

54. Organic Compounds
Proteins can be described in terms of four structural levels. 3. Tertiary Structure is superimposed on the secondary structure. This represents the shape of the entire protein. It is usually described as globular or fibrous.

55. Tertiary structure of prealbumin
(transthyretin), a protein that
transports the thyroid hormone
thyroxine in serum and cerebro-
spinal fluid. (
Superimposed on secondary structure. a-Helices and/or b-sheets are
folded up to form a compact globular molecule held together by
intermolecular bonds.

56. Organic Compounds
. 3. Tertiary Structure is stabilized by covalent bonds of adjacent cysteine amino acids.

57. Tertiary Structure

58. Importance?

59. Organic Compounds
Proteins can be described in terms of four structural levels. 4. Quaternary Structure involves the interaction of two or more protein chains. Hemoglobin is an example of this.

60. Hemoglobin

61. Organic Compounds
What maintains the shape of the protein?
Temperature

62. Organic Compounds What maintains the shape of the protein? TemperaturepH

63. Organic Compounds What maintains the shape of the protein? TemperaturepH
salt concentrations

64. Organic Compounds What maintains the shape of the protein? TemperaturepH
salt concentrations
Changes in any of these results in the protein being denatured.

65. Organic Compounds
Remember enzymes?

66. Organic Compounds
Remember enzymes?
They are:
substrate specific

67. Organic Compounds Remember enzymes? They are: substrate specific
act as a catalyst by reducing the activation energy
action is do to a “lock and key” mechanism

68. . WITHOUT ENZYME WITH ENZYME Activation energy required
Less activation
energy required
Reactants
Reactants
Product
Product

69. Product (P) e.g., dipeptide Substrates (S) e.g., amino acids Energy is
absorbed;
bond is
formed.
Water is
released.
Peptide
bond +
Active site
Enzyme-substrate
complex (E-S)
Enzyme (E)
Enzyme (E)
Substrates bind
at active site.
Enzyme changes
shape to hold
substrates in
proper position. 1
Internal
rearrangements
leading to
catalysis
occur. 2
Product is
released. Enzyme
returns to original
shape and is
available to catalyze
another reaction. 3

70. Organic Compounds
Remember DNA?
Contains a deoxyribose sugar

71. Organic Compounds Remember DNA? Contains a deoxyribose sugar
Phosphate group

72. Organic Compounds Remember DNA? Contains a deoxyribose sugar
Phosphate group
Four bases

73. Organic Compounds Remember DNA? Contains a deoxyribose sugar
Phosphate group
Four bases
Adenine
Guanine
Cytosine
Tyrosine

74. . Sugar: Deoxyribose Base: Adenine (A) Phosphate Thymine (T) Sugar
Adenine nucleotide
Thymine nucleotide
Hydrogen
bond
(a)
Deoxyribose
sugar
Sugar-phosphate
backbone
Phosphate
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
(b)
(c) Computer-generated image of a DNA molecule

75. Organic Compounds Remember RNA? Contains a ribose sugar
Phosphate group
Four bases
Adenine
Guanine
Cytosine
Uracil

76. Table 2.4 Comparison of DNA and RNA

77. How Does ATP Work?
Coupled reactions where stable molecules become phosphorylated and activated

78. . High-energy phosphate bonds can be hydrolyzed to release energy.
Adenine
Phosphate groups
Ribose
Adenosine
Adenosine monophosphate (AMP)
Adenosine diphosphate (ADP)
Adenosine triphosphate (ATP)

79. Review
1. What are the 3 classes of carbohydrates?

80. Review
1. What are the 3 classes of carbohydrates? 2. What reaction is used to join simple sugars together?

81. Review
1. What are the 3 classes of carbohydrates? 2. What reaction is used to join simple sugars together? 3. How do triglycerides and phospholipids differ?