chapter 4 carbon and the molecular diversity of life p. 58-67
TRANSCRIPT
Importance of Carbon
Cells are composed of C-based compounds– Proteins– DNA– Lipids– Carbohydrates
Other cell ingredients include H, O, N, P, S– Along w/C, are found in relatively same
proportions in all organisms
Organic Chemistry is the Study of Carbon Compounds
Compounds containing Carbon are called Organic
– Organic cmpnds can be small (CO2) to very large (proteins)
– Organic cmpnds found in living organisms can now be synthesized in a laboratory (i.e. acetic acid)
C Atoms are Versatile Building Blocks
C’s electron configuration determines its bonding properties
– 4 valence e- cause C to form 4 covalent bonds with other atoms (“tetravalence”)
Carbon Molecule Shapes
A molecules shape often determines its function
When C forms 4 single bonds, takes on tetrahedron shape
When C=C, molecule lies flat
The e- configuration of C allows it to easily form covalent bonds with H, O, N, & other C – Will form single/double bonds until valence shell
is full
Variations in C Skeletons
C chains form the skeleton of most organic molecules
– Vary in length– May be straight, bent, or
in rings
Hydrocarbons
Hydrocarbon: an organic molecule containing only carbon and hydrogen (i.e. petroleum)
– Non-polar– Hydrophobic– Many molecules have
sections of hydrocarbons (i.e. fats)
– Able to store large amounts of energy
Isomers
Isomers: compounds with same molecular formula but different structure and properties
3 types:– Structural– Geometric– Enantiomers
Structural Isomers
Differ in covalent arrangement
– As size of C skeleton increases, # possible structural isomers increases
– i.e.: C8H14 = 18 variations; while C20H42 has 366,319 variations!!
Butane Isobutane
(Both are C4H10)
Geometric Isomers
Differ in their spatial arrangement– Due to inflexibility of double bonds– Can affect function (i.e.: vision)
Enantiomers
Molecules that are mirror images of each other
Caused by an Asymmetric Carbon: a C bonded to 4 different atoms/molecules
– May have drastic effect on the function of the molecule (i.e.: thalidomide)
Functional Groups
Functional Groups: attachments to C skeletons that are involved in chemical reactions
-Behave consistently from molecule to molecule
-All are hydrophilic, so they help increase the solubility of organic molecules in H2O