Hydroxyl group

Definition

A hydroxyl group is a functional group consisting of an oxygen atom bonded to a hydrogen atom (-OH). It is commonly found in alcohols and plays a vital role in the structure and function of lipids.

5 Must Know Facts For Your Next Test

1. Hydroxyl groups are polar, which allows them to form hydrogen bonds with water molecules, increasing solubility.
2. In fatty acids, hydroxyl groups can be involved in forming ester linkages during triglyceride formation.
3. Phospholipids contain hydroxyl groups that contribute to their amphipathic nature, crucial for membrane structure.
4. The presence of hydroxyl groups in sterols like cholesterol affects their interaction with membrane lipids.
5. Lipases are enzymes that hydrolyze ester bonds in lipids, often acting on the hydroxyl groups.

Review Questions

• What role do hydroxyl groups play in the solubility of lipids?
• How do hydroxyl groups contribute to the formation of triglycerides?
• In what way do hydroxyl groups affect the properties of phospholipids?

Related terms

Fatty Acid: A carboxylic acid with a long aliphatic chain, which may be saturated or unsaturated.

Phospholipid: A lipid containing a phosphate group in its molecule, essential for cell membranes.

Sterol: A subgroup of steroids with a hydroxyl group at the 3-position of the A-ring, such as cholesterol.