BRAINCAKESolvents
Water is a polar solvent. All living cells exist in an aqueous internal or external environment.
The phospholipid membrane is not soluble in water so forms a selectively permeable barrier to substances on either side of the membrane.
Small, non-polar molecules and substances that dissolve in lipid can pass through between gaps between the hydrophobic tails of the phospholipid molecules.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
Key terms in this lesson
- phospholipid bilayer
- Two layers of phospholipid molecules arranged with hydrophilic heads facing outwards and hydrophobic tails facing inwards, forming the basic structure of cell membranes.
- selectively permeable
- Describes a membrane that allows some substances to cross it but not others.
More in Plasma Membrane
- Extrinsic Proteins
- Cholesterol
- Sites of Chemical Reactions
- Effect of Temperature
- Diffusion
- Diffusion Across Membranes
- Facilitated Diffusion
- Active Transport
All 18 lessons in Plasma Membrane · All OCR AS-level Biology topics