urea in the olive oil

Na⁺ and Cl^- in the olive oil

phospholipid at the interface between the oil and water

phospholipids with their tail groups in the water and head groups in the olive oil

phospholipid in the olive oil

Gap junctions

Occluding junctions

Microfilaments

Desmosomes

Tight junctions

Provides covalent bonds between phospholipids in the cell membrane

Binds adjacent hydrophobic tails of lipid bilayers to make the cell membrane more rigid

Form aqueous pores in the cell membrane that allow substances to easily traverse the membrane

Form kinks in the cell membrane allowing substances to traverse more easily

Form kinks in the cell membrane making it harder for substances to traverse the membrane

A, B and C

B and C

To act as a permeability barrier between inside and outside

To use cholesterol to make the membrane more rigid

To provide structures that aid in cell recognition by the immune system

is charged

decreases membrane fluiditiy

improves membrane permeability

is a prominent lipid component of all membranes in a cell.

forms the vesicles of the Golgi apparatusincrerases

Cell membranes contain only phospholipid and protein molecules.

Micelles are tiny droplets of phospholipids in water. In each micelle the headgroups of the phopholipids are exposed to the water and the tailgroups protected from the water in the centre of the micelle.

Integral proteins can be removed from biological membranes by mild chemical treatments that leave the lipid bilayer intact.

The lipid bilayer of biological membranes is formed by phospholipid molecules with hydrophilic fatty-acid, tailgroups and hydrophobic headgroups.

The biological membrane is described as fluid because the phospholipid molecules but not the proteins can move around in the lipid bilayer.

a relatively high concentration of calcium

a high concentration of organic ions and proteins

a high concentration of sodium and a low concentration of potassium

a relatively low concentration of magnesium

a high concentration of inorganic ions