Chemistry

Functional Groups

Organic Chemistry

The study of carbon-containing compounds Carbon atoms are the most versatile building

blocks of molecules With a total of 6 electrons, a carbon atom has

2 in the first shell and 4 in the second shell Carbon usually completes its valence shell by

sharing electrons with other atoms in four covalent bonds

This tetravalence by carbon makes large, complex molecules possible

Carbon Chains

form the skeletons of most organic molecules

the skeletons may vary in length and may be straight, branched, or arranged in closed rings

the carbon skeletons may also include double bonds

Isomers

Structural isomers Geometric isomers Enantiomers

Structural Isomers

Variation in covalent partners pentane has a straight skeleton and isopentane

has a branched skeleton same molecular formula C5H12

Geometric Isomers

Variation in arrangement about a double bond rhodopsin (in the retina) from one geometric

isomer to another

Enantiomers Variation in spatial arrangement, mirror images enantiomers are possible if there are four different

atoms or groups of atoms bonded to a carbon they are like left-handed and right-handed

versions usually one is

biologically active, the other inactive

Functional Group

A specific configuration of atoms commonlyattached to the carbon skeletons of organic molecules and usually involved in chemical reactions

Hydroxyl -OH Carbonyl CO Carboxyl -COOH Amino -NH2 Sulfhydryl -SH Phosphate -PO4

-2 (-OPO3-2)

Methyl -CH3

1.Hydroxyl Group (-OH)

a hydrogen atom forms a polar covalent bond with an oxygen which forms a polar covalent bond to the carbon skeleton.

Organic compounds with hydroxyl groups are alcohols and their names typically end in -ol

2.Carbonyl Group ( CO)

consists of an oxygen atom joined to the carbon skeleton by a double bond

aldehyde -If the carbonyl group is on the end of the skeleton

ketone - if not at the end

3.Carboxyl Group (-COOH) carbon atom with a double

bond with an oxygen atom and a single bond to a hydroxyl group.

carboxylic acids - compounds with carboxyl groups

Acidic properties - because the combined electronegativities of the two adjacent oxygen atoms increase the dissociation of hydrogen as an ion (H+)

4. Amino Group (-NH2)

nitrogen atom attached to twohydrogen atoms and the carbon skeleton.

Amines - Organic compounds with amino groups.

Basic properties - because ammonia can pick up a hydrogen ion (H+) from the solution

5. Sulfhydryl Group (-SH)

sulfur atom bonded to a hydrogen atom and to the backbone

thiols - organic molecules with sulfhydryl

Sulfhydryl groups help stabilize the structure of proteins

6. Phosphate Group (-OPO3

-2) Phosphorus bound to four

oxygen atoms (three with single bonds and one with a double bond).

Phosphate groups are anions with two negative charges as two protons have dissociated from the oxygen atoms.

One function of phosphate groups is to transfer energy between organic molecules

7. Methyl Group (-CH3)

Carbon bonded to 3 hydrogen atoms. The methyl group may be attached to a or a different atom

Addition of methyl to molecule changes its shape and function

Activity: identify the function group

C - NH

H

H

H

HMethylamine

N - C - C O

OH

H

CH3

H

H

Alanine

Activity

ATP (adenosine triphosphate)

The End