cell membranes

Question 1

what are phospholipids?

Answer 1

chemicals in which glycerol bonds with two fatty acids and an inorganic phosphate group

Question 2

what happens when the phospholipids contact water?

Answer 2

polar phosphate part is hydrophilic and dissolves in water
lipid tails are hydrophobic and repel water

Question 3

what is a monolayer?

Answer 3

molecules that are tightly packed in water with hydrophilic heads in water and hydrophobic tails in air

Question 4

what is a micelle?

Answer 4

cluster of molecules with hydrophilic heads pointing outwards and hydrophobic tails tucked inside

Question 5

why does a phospholipid form a bilayer?

Answer 5

because there are water based solutions on either side of the membrane while in a monolayer develops at a surface between air and water

Question 6

what is a bilayer?

Answer 6

double layer of closely packed molecules with water on each side. Hydrophilic heads point in the water and while hydrophobic tails are kept in the middle

Question 7

what molecules does the phospholipid bilayer let through?

Answer 7

fat-soluble compounds, non polar compounds

Question 8

what is the fluid mosaic model?

Answer 8

current model of the structure of the cell membrane including floating proteins forming pores, channels and carriers in the lipid bilayer

Question 9

what are gated channels?

Answer 9

protein channels through lipid bilayer of a membrane that are open or closed, depending on conditions in the cell

Question 10

why does cholesterol decrease the permeability of the membrane?

Answer 10

cholesterol is a rigid molecule, makes the membrane stronger and stable. This makes it harder for small molecules and ions to pass through