How do proteins differ from carbohydrates and lipids?

1 Answer
Jun 13, 2015

Proteins are large molecules that consist of long chains of amino acids joined together by peptide (#"CONH"#) bonds.



The structure of a small protein is

Proteins have polar C=O and N-H groups, so they are able to form hydrogen bonds with other molecules and with each other.


Carbohydrates have many polar #"OH"# groups.

A typical carbohydrate is starch, which is consists of many glucose units (#"C"_6"H"_12"O"_6 #) joined together.

Most carbohydrates are hydrophilic and soluble in water because of their polar #"OH"# groups.


Lipids are hydrophobic and insoluble in water.

They have varied structures, but all have a polar "head" and a large nonpolar "tail"".

Fats and oils are typical lipids.

The structure of a typical fat is

The molecule is mostly nonpolar hydrocarbon with some polar #"C=O"# groups at one end.