Download Chapter 4: Carbon and the molecular diversity of life

Chapter 4: Carbon and the molecular diversity of life
The importance of carbon
1. Organic chemistry is the study of carbon compounds
a. Vitalism gives way to mechanism as chemists synthesize organi
molecules of increasing complexity
2. Carbon atoms are the most versatile building blocks of molecules
a. Can form 4 covalent bonds (tetravalence)
b. Geometry can be tetrahedron (single bond) or planar (double bond)
3. Variation in carbon skeletons contributes to the diversity of organic molecules
a. Can vary in length from CH4 and CO2 to C in the thousand
b. Can vary in shape form linear to branching to complex folds and twists
c. Can form rings
d. Can mix single and double bonds
e. Isomerism is prevalent
i. Compound with the same molecular formula but different
shapes and thus different properties
ii. Structural isomers: differ in the covalent arrangement if their
atoms
iii. Geometric isomers: same covalent bonding but differ in
special arrangement
iv. Enantiomers: molecules that are mirror images of each other
1. an asymmetric carbon has four differrnt atoms aor
groups of atoms attached
2. four gropus can be arranged around the asymmetric
centier to form mirror images, can be a left handed
version and a right handed version of the molecule
3. important becsue in biology one enantiomer is active
the other usually is not
Functional groups
1. Functional groups contribute to the molecular diversity of life
a. Chemical reactions of organic molecules are determined by the
functional groups (biological activity of organic molecules are
determined by the functional groups); there are six important
functional groups in biochemistry
b. The hydroxyl group (OH)
i. Polar (so forms H bonds)
c. The carbonyl group (CO)
i. Produces aldehydes and ketones depending on where the O is,
important in sugars
d. The carboxyl group (COOH)
i. These are organic acids
e. The amino group (NH2)
i. Acts as a base
f. The sulfhydryl group (SH)
i. Forms thiols, S analog of OH
g. The phosphate group (PO4)
One O covalently bonds the PO4 group to the C skeleton