Review
Overview
Finish O-Chem
Start Macromolecules
Isomers
Three types of isomers:
Structural Isomers
Differ in the covalent arrangement of their atoms
H C C
H
H C H
H C H
H C H
C
H C H
C
H C H
H
H H
H H H C H C
C H
C
H H H C H X H
H
X H
X H CO2H
C CH3
X CO2H C CH3
H
NH2 NH2
H
Geometric Isomers
Have same covalent partnerships, but differ in their spatial relationships Due to double bond between carbon atoms
H H C H
H C H
H C H
H C H
H C H
H
H
H H H C H
H C C
C H
H H H C H
H
X H
C
X
H
C C
X
H CO2H
C
H CO2H
X
cis
H C CH3 NH2 NH2
trans
C
CH3 H
Enantiomers
Molecules that are mirror images of each other
H H C H H C H H C H H C H H C H H H H H H C H H C C C H H H H C H H
*Little black carbons are asymmetric carbons. They X H X X C C C C have 4 bonds. X H H H
CO2H C CH3 CO2H
H
NH2 NH2
C
CH3
H
Left `L'
Right `D'
Enantiomers
Enantiomers are important in the pharmaceutical industry
L-Dopa (effective against Parkinson's disease)
D-Dopa (biologically inactive)
Functional Groups
The parts of molecules involved in chemical reactions Distinctive properties of organic molecules depend on arrangement of carbon skeleton and the molecular components attached to the skeleton.
Functional Groups
`Replace' one or more of the hydrogens bonded to the carbon skeleton Each functional group behaves consistently Number & arrangement of functional groups on a molecule give it its unique properties
Functional Groups
Estradiol
OH CH3
HO
Female lion
OH CH3
CH3
O
Testosterone
Male lion
Functional Groups *MEMORIZE*
Six functional groups are important in the chemistry of life
Hydroxyl Carbonyl Carboxyl Amino Sulfhydryl Phosphate
Hydroxyl Group
O
OH
(may be written HO )
C
Not the same as hydroxide ion. Not charged. Oxygen atom bound to Hydrogen atom. 2 covalent bonds. Found in alcohols. Polar.
Carbonyl Group
O
O
C
OH
(may be written HO )
C
OH
A carbon atom double bound to an oxygen atom. Carbonyl bound to carbon skeleton. Carbon in middle can be bound to 2 other Carbons or 1 Carbon & 1 Hydrogen. Found in Ketones & Aldehydes. Polar. Aldehydes typically end in al. Alcohols typically end in ol.
Carboxyl Group
O
O
C
OH
written HO )
C
OH
Bound to Carbon skeleton. Written as COOH. Found in Carboxylic Acids. Acts as an Acid. Typically present in ionic form. If no Hydrogen then it's COO.
Functional Groups in Organic Molecules
H H C H H O H H H C H H C C OH O
H
C H
OH
H
C
C
H
H
H
H C H
H C H C
O
H
Amino Group
H
N H
SH (may be written HS )
Consists of a Nitrogen atom covalently bonded to two Hydrogen atoms. Found in Amines. Acts as a base. Typically present in ionic form.
Sulfhydryl Group
H N H
SH
(may be written HS )
O O P OH OH
Sulfur atom bound to Hydrogen atom. Found in thiols. Important in protein structure.
Phosphate Group
H N H
SH
(may be written HS )
O O P OH OH
Found in organic phosphates. Typically found in ionized form. Each Oxygen has a negative charge. Phosphate in ionized form is OPO3
Functional Groups in Organic Molecules
O C HO
H C H N
H
H H C
H
H
OH OH H SH H C H C H C H O
O P O O
C
H
H
Glycine
Ethanethiol
Glycerol phosphate
ATP
Adenosine triphosphate Important source of energy for cellular processes
ATP
Summary
Carbon skeletons make up backbone of organic molecules Carbon skeletons vary greatly Functional groups add personality to carbon skeletons
Introduction to Macromolecules
September 13, 2006
The Molecules of Life
Small organic molecules join together to form larger molecules Macromolecules:
Large molecules formed by the joining of smaller molecules
Macromolecules
Four main classes of large biological molecules Carbohydrates Lipids Proteins Nucleic Acids
Macromolecules
Most macromolecules are polymers that are built from monomers Polymer: -A long molecule consisting of many similar or identical building blocks linked by covalent bonds Monomer: -The repeating unit used as the building block of polymers
Polymers
Long molecules consisting of many similar building blocks Carbohydrates, proteins...etc?
Monomers
Carbohydrates: monosaccharides
Proteins: amino acids
Nucleic Acids: nucleotides
*4 nucleotides used to make DNA ATCG
Making Polymers
Monomers join together to form larger molecules by condensation reactions called dehydration reactions
HO
1
2
3
H
HO
H
Short polymer
Dehydration removes water a molecule, forming a new bond HO
Unlinked monomer
H2O
1
2
3
4
H
Longer polymer
Breaking Polymers
Polymers are disassembled by hydrolysis Hydrolysis = to break with water Hydrolysis is basically the reverse of the dehydration reaction.
Breaking Polymers
HO
1
2
3
4
H
Hydrolysis adds a water molecule, breaking a bond
H2O
HO
1
2
3
H
HO
H
Diversity of Polymers
Each class of polymer is formed from a specific and limited set of monomers Immense variety of polymers can be built from a small set of monomers
Carbohydrates
Serve as fuel and building material
Includes both sugars and their polymers
Monosaccharides
The monomer of carbohydrates Simple sugars Can be used for fuel Can be combined to form polymers
Monosaccharides
Molecular formula: CH2O
Contain carbonyl -Aldose -ketose Contain hydroxyls
*-ose usually denotes sugar or carbohydrate
Monosaccharides
Molecular formula: CH2O
Carbon skeleton length: n(CH2O) -Typically 3-7 carbons Spatial arrangement of atoms
Monosaccharides
Triose sugars Pentose sugars (C3H6O3) (C5H10O5)
H C H C C H OH OH H H H
Hexose sugars (C6H12O6)
H C
O
H C C C C
O OH OH OH
O C
C C
H C H HO HO H H C C C C C H
O OH H H OH OH
H
HO H
OH
H OH
Aldoses
H
Glyceraldehyde
H
C H
OH
H
H
C
C H
OH
OH
Ribose
Glucose
H H C OH C O H H H H H C OH C O HO H H H H
Galactose
C OH C O
Ketoses
H
C OH H
C OH C OH C OH
C H C OH C OH
Dihydroxyacetone
H
H
C OH H
Ribulose
Fructose
Monosaccharide Structure
Linear carbon skeleton
Ring structures -Most monosaccharides with 5 or 6 carbons form rings in aqueous solutions
Monosaccharide Structure
H
1C
O
6CH OH 2 6CH OH 2
H HO
2
3
C
OH
5C
H
H
4C
O
H
5C
O
1C
CH2OH H
6
C
H
H OH
3
H
4C
H
4
5
O
1
H OH
4
H
H
C
5
OH
H
2C
1C
OH
OH
O
H OH
3C
H
2C
H OH
3 2
C
C
OH
HO OH
H
OH
H
6
C
H
OH
H
OH
H
OH
Numbering Carbon Atoms
Aldoses: numbering begins at aldehyde Ketoses: numbering begins with the end closest to the ketone group
Disaccharides
Consist of two monosaccharides that are joined by a glycosidic linkage Glycosidic linkage: -The covalent bond formed between two monosaccharides by a dehydration reaction
Disaccharides
CH2OH CH2OH H
CH2OH H
OH OH H O H OH H
CH2OH H
14 1 glycosidic linkage
H HO
O H OH H H OH
H OH
HO
O
H OH
H
H
4
O H OH H
H OH
H OH
HO H
OH
O
H
Maltose
OH
H2O
Glucose Glucose
CH2OH
H
HO
O H OH H
CH2OH H OH HO
CH2OH O HO CH2OH HO H OH
Sucrose
H
H
O H OH H
H
H
H
OH
12 glycosidic 1 linkage
CH2OH O
2
H
H
HO
O OH H
CH2OH
OH H2O
H
Glucose
Fructose
Disaccharides
CH2OH CH2OH H
CH2OH H
OH OH H O H OH H
CH2OH H
14 1 glycosidic linkage
H HO
O H OH H H OH
H OH
HO
O
H OH
H
H
4
O H OH H
H OH
H OH
HO H
OH
O
H
Maltose
OH
H2O
Glucose Glucose
CH2OH
H
HO
O H OH H
CH2OH H OH HO
CH2OH O HO CH2OH HO H OH
Sucrose
H
H
O H OH H
H
H
H
OH
12 glycosidic 1 linkage
CH2OH O
2
H
H
HO
O OH H
CH2OH
OH H2O
H
Glucose
Fructose
Polysaccharides
Macromolecule Polymers of sugars joined by glycosidic linkages Serve many roles in organisms
Storage Structural
Storage Polysaccharides
Hydrolyzed when sugar is necessary for cells Starch (plants) Glycogen (animals)
Starch
A polymer consisting entirely of glucose monomers Major storage form of glucose in plants
Starch
Chloroplast Starch
1 m
Amylose
Amylopectin
Glycogen
A polymer consisting of glucose monomers More branched than amylopectin Glycogen stored in liver and muscle cells
Glycogen
Mitochondria Giycogen granules
0.5 m
Glycogen
Structural Polysaccharides
Building materials for structures that protect a cell or whole organism Cellulose Chitin
Cellulose
Major component of the tough walls of plant cells Polymer of glucose
Glucose Ring Structures
Alpha Beta
Carbonyl carbon below plane of ring
Carbonyl carbon above plane of ring
Starch vs. Cellulose
Every single glucose monomer in cellulose is in beta form.
Starch vs. Cellulose
Notice: hydroxyl groups on opposite sides
Cellulose
Cellulose is Difficult to Digest
Enzymes that digest starch are unable to hydrolyze the linkages of cellulose Due to difference in shape of the two molecules Insoluble fiber
Chitin
Used by arthropods to build their exoskeletons Similar to cellulose
*Same thing as cellulose but it has nitrogen appendage thing
Summary
Carbohydrates
-Monosaccharides -Disaccharides -Polysaccharides