Question

How do lipids differ from carbohydrates and proteins?

Answer 1

Lipids are hydrophobic and insoluble in water. Carbohydrates and proteins are hydrophilic and able to form hydrogen bonds with water.

Explanation:

Lipids

Lipids 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.

Proteins

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

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.