1. Functional Groups
A few chemical groups are key to the functioning of molecules
Distinctive properties of organic molecules depend on the carbon skeleton structure and on the molecular components attached to it
A number of characteristic groups can replace the hydrogens attached to skeletons of organic molecules

2. Functional groups
Are parts of organic molecules that are involved in chemical reactions
The number and arrangement of functional groups give organic molecules distinctive properties
 hydroxyl  amino
 carbonyl  sulfhydryl
 carboxyl  phosphate
Affect reactivity
makes hydrocarbons hydrophilic
increase solubility in water

3. Hydroxyl
Students may be confused. OH- is known as “the hydroxide ion” in inorganic chemistry and signifies a base, which is all they know at this point. They may or may not know that the OH group attached to a carbon skeleton forms an alcohol. Emphasize the polarity of an alcohol which is exactly why alcohols are water soluble.

4. Carboxyl
Ah, this has many, many names thanks to inorganic and organic chemists that can’t get along! The carboxyl group terminology is in most biology books, as in “carboxylic acids” which we’ll see again as we build amino acids. The “acetyl” group as it is often known in inorganic chemistry.

5. Phosphate
Here’s a biggie! Students should know the phosphate ion from Chemistry I. Furthermore they should already know it has a -3 charge. In ATP we have three of those -3 ions stacked next to each other which is a great deal of negative ion-negative ion repulsion!

6. Amino/Amine
Students should already know that “ammonia”, the NH3 molecule is a weak inorganic base. Emphasize that this is the “amine” portion of amino acid fame.