An increase in temperature will increase the kinetic energy of molecules. This means that if a cell is heated the phospholipids will vibrate more, creating larger gaps for molecules to diffuse through. At a certain temperature the proteins will start to denature. This will leave big gaps in the membrane resulting in an increase in the volume of pigment/ molecule diffusing out of the cell.
Movement of water across a selectively permeable membrane from an area of high water potential to an area of low water potential - down a concentration gradient - passive
Large molecules across the membrane, which attach and the protein changes shape - the binding of the molecule changes tertiary structure - which releases the molecule on the other side of the membrane
The net movement of non-polar particles from a high concentration to a low concentration until equilibrium is reached, it is passive and goes down a concentration gradient.
The head is hydrophilic - attracting water so it faces out towards the water. The tail is hydrophobic - it repels water so it faces inwards away from the water.
Cholesterol molecules fit between the phospholipids, binding to the hydrophobic tails of the phospholipids, causing them to pack more closely together. This restricts the movement of the phospholipids, making the membrane less fluid and more rigid.