1.3 membrane structure

Question 1

what is the structure of a phospholipid?

Answer 1

polar head (hydrophilic)
two nonpolar tails (hydrophobic)

Question 2

how do phospholipids arrange themselves?

Answer 2

in a bilayer with the tails facing inwards and the heads facing outwards

Question 3

what proteins are found in a phospholipid bilayer?

Answer 3

integral proteins (permanently attached)
peripheral proteins (temporarily attached)

Question 4

what is the role of protein in a bilayer?

Answer 4

transport, cell recognition, and attachment.

Question 5

what is the role of cholesterol in bilayers?

Answer 5

acts as a stabilizing component and separates the phospholipid tails to prevent crystallization of the membrane in animal cells

Question 6

what is the davson-daniell model?

Answer 6

based on microscopic observation, proteins were layered on both sides of a lipid layer, this model has been proved incorrect.

Question 7

What is the Singer-Nicolson model( fluid mosaic model)?

Answer 7

used fluorescent tagging and freezing fracturing to split the membrane in half and view the internal components, showing proteins were in the bilayer.

Question 8

what does amphipathic mean?

Answer 8

hydrophilic and hydrophobic