Grade 11 Biology: Cell Membrane and Phospholipids

Vocabulary flashcards covering the structure and permeability of the cell membrane and its phospholipid bilayer as described in the Grade 11 Biology excerpt.

Phospholipids

Lipid molecules consisting of a phosphate head attached to a glycerol molecule and two fatty acid tails.

Hydrophilic surfaces

The parts of the phospholipid molecules (phosphate heads) that are in contact with aqueous fluid both inside and outside of the cell.

Hydrophobic region

The interior of the membrane formed by fatty acid tails facing each other, also described as the non-polar region.

Semipermeable (partially permeable)

A characteristic of the cell membrane that allows certain materials, such as lipid-soluble (non-polar) substances, to pass through while preventing others.

Small hydrophobic molecules

Molecules such as oxygen ($O_2$) and carbon dioxide ($CO_2$) that cross the cell membrane rapidly.

Small polar molecules

Molecules such as water ($H_2O$) and ethanol ($C_2H_5OH$) that can pass through the membrane, but do so slowly.

Highly charged molecules

Substances such as ions whose diffusion is restricted by the cell membrane and require specific transport proteins for passage.

Large molecules

Substances like sugars and amino acids that cannot easily pass through the membrane and rely on embedded transport proteins.

Transport proteins

Proteins embedded in the membrane that facilitate the passage of ions and large molecules like sugars and amino acids.

Principal components of cell membrane

A combination of lipids (phospholipids and cholesterol), proteins (integral and peripheral), and carbohydrates (glycolipids or glycoproteins).

Lipid components

The primary fats in the cell membrane consisting of phospholipids and cholesterol.

Protein components

Structural elements of the cell membrane categorized as integral and peripheral proteins.

Carbohydrate components

Elements of the cell membrane that exist as glycolipids or glycoproteins.