plasma membranes (transport across membranes)

Question 1

what is a plasma membrane?

Answer 1

a bilayer that regulates transport of substance into and out of the cell (its partially membrane)

Question 2

what are plasma membranes composed of?

Answer 2

several tupes of molecules ( phospholipid, glycoproteins, cholestrol, glycolipids)

Question 3

what do phospholipids form?

Answer 3

bilayers which have hydrophillic heads and hydrophobic tails

Question 4

what does the hydrophobic centre do?

Answer 4

prevents water-soluble substances from diffusing through

Question 5

how are proteins arranged throughout the plasma?

Answer 5

intersped throughout it or may extend across the entire bilayer or are attached to small sections of it

Question 6

what are the functions of the protein in the plasma?

Answer 6

act as protein channels or carrier proteins involved in transport or substances, acts as receptor for detecting hormones/ neurotransmitters/ antigens, allows cells to adhere togethere.

Question 7

what do plasma membranes contain?

Answer 7

glycolipids & glycoproteins

Question 8

what are glycoproteins and glycolipids?

Answer 8

lipids or proteins which have carbohydrates attached (glyco-) and they usually act as either receptors or recognition sites (antigens)

Question 9

what is the arrangement of plasma membrane known as ?

Answer 9

fluic mosaid model

Question 10

what is the fluid mosaic model described as being?

Answer 10

fluid do to its flexibility and ability to change its shape and “mosaic” as the embedded proteins vary in size & shape

Question 11

why is there cholestrol in the plasma?

Answer 11

making membranes less fluid and provides mechanical support