ch5 - factors affecting membrane structure

Name the two factors which affect membrane structure and permeability 

Temperature

Solvents 

What occurs at low temperatures (below 0°C)

phospholipids have little kinetic energy & are tightly packed together forming a rigid cell membrane = low membrane permeability 

What occurs as temperature increases

phospholipids gain kinetic energy so move faster and will no longer be packed as closely together increasing membrane permeability - molecules diffuse through phospholipid bilayer quicker  

What occurs at high temps (above 40°C)

phospholipid bilayer start to break down & channel and carrier proteins denature further increasing membrane permeability - phospholipid bilayer will no longer be able to control what enters or leaves the cell

What is an organic solvent

liquids such as ethanol in which lipid substances dissolve in

What happens when a cell is placed in an organic solvent

phospholipid bilayer dissolves which causes the membrane to become more fluid simultaneously increasing the membranes permeability