Fundamental building blocks of all cell membranes are phospholipids, which consist of two hydrophobic fatty acid chains linked to a phosphate-containing hydrophilic head group. explain how the structure of the bilayer membrane acts as a stable barrier between two aqueous (water based) areas.

Phospholipids spontaneously form stable bilayers. In phospholipid layer in cell membrane, there are hydrophilic heads (polar part of the layer) and hydrophobic tails (nonpolar part of the layer).

Polar head groups are exposed to water and their hydrophobic tails buried in the interior of the membrane.

1) Small, non-polar molecules diffuse easily through this layer, no energy is required, this is passive transport.

2) Polar molecules cannot diffuse through phospholipid layer using passive transport, because hydrophobic tails does not allow that (polar molecules are reppeled), energy is required for that, this is active transport.

Also, the lighter (smaller) particles move more quickly than heavier (larger) ones at the same temperature.

answer

i think the answer is a) as air pressure in an area increases, the density of the gas particles in that area decreases.

hope it

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?