Sterols

Definition

Sterols are a subgroup of steroids with a hydroxyl group at the 3-position of the A-ring. They play crucial roles in cell membrane structure and function.

5 Must Know Facts For Your Next Test

1. Sterols, such as cholesterol, are essential components of eukaryotic cell membranes, providing stability and fluidity.
2. Ergosterol is a key sterol in fungal cell membranes and a target for antifungal drugs.
3. Sterols help modulate membrane permeability and fluidity, crucial for cellular processes.
4. Many antimicrobial drugs target sterol synthesis or function to disrupt microbial cell membranes.
5. Prokaryotic cells generally lack sterols in their membranes, which is a distinguishing feature from eukaryotic cells.

Review Questions

• What role do sterols play in eukaryotic cell membranes?
• Why is ergosterol an important target for antifungal drugs?
• How do sterols affect membrane permeability and fluidity?

Related terms

Cholesterol:

A type of sterol found in animal cell membranes that helps maintain membrane integrity.

Ergosterol:

A sterol component of fungal cell membranes targeted by many antifungal drugs.

Phospholipid Bilayer: A fundamental structure of cell membranes consisting of two layers of phospholipids with embedded proteins and other molecules like sterols.