History of the cell membrane structure

Question 1

what was discovered in 1915 about the cell membrane

Answer 1

studied red blood cells
cell membrane contains proteins and lipids

Question 2

what did Gorter and Grendel discover in 1924

Answer 2

cell membrane is a lipid bilayer

Question 3

what did Davson and Danielli & Robertson discover in 1950

Answer 3

Dark outer layers = protein, lighter region = lipid
three layer sandwich model
layer of protein covering surface of membrane
Later interpretation changed – dark region = phosphate heads
light region = lipid tails

Question 4

what did the freeze fracture evidence discover 1960

Answer 4

The membrane was a smooth surface with bumps in it
The bumps are proteins
Proteins are embedded IN the lipid bilayer rather than on the outside of the bilayer

Question 5

what did Frye and Edidin discover 1970

Answer 5

Cell membrane must be fluid (proteins diffused through membrane)

Question 6

what did Unwin and Henderson discover in 1980

Answer 6

Peripheral proteins loosely attached
Integral proteins are fully embedded in membrane

Question 7

what did Lectins research evidence discover 1980

Answer 7

outer surface of the membrane is different to the inner surface carbohydrate only on the outside