Cell Membranes And Transport

Question 1

Describe the fluid mosaic model

Answer 1

Molecules of membrane are free to move (fluid)

Proteins are scattered through bilayer are varied in size and shape (mosaic)

Question 2

What are the two types of proteins within the bilayer

Answer 2

Extrinsic and Intrinsic

Question 3

Define bilayer

Answer 3

Two layers of phospholipids

Question 4

Describe the head of the phospholipid

Answer 4

Polar hydrophilic phosphate head

Faces towards the aqueous solutions of the cytoplasm and outside of cell.

Question 5

Describe tail of phospholipid

Answer 5

Non polar hydrophobic fatty acid tail

Faces inwards to avoid the aqueous solutions of the cytoplasm and outside of cell

Question 6

What is the role of the phospholipid

Answer 6

Provides barrier to large non-polar molecules
Allows small polar molecules to diffuse through

Question 7

Define a polar molecule

Answer 7

Water soluble molecule that has an imbalance of charges

Question 8

describe the role of extrinsic proteins

Answer 8

act as receptor cells for hormone signals, form recognition sites and identify cells

Question 9

describe the role of channel proteins

Answer 9

facilitate diffusion of small, polar molecules trough the phospholipid bilayer. allow active transport of ions

Question 10

describe the role of carrier proteins

Answer 10

carry large, non-polar. not water soluble molecules across the cell surface membrane

Question 11

What is the bilayer weak to

Answer 11

Ethanol
pH
Temperature