Membrane Structure

Which evidence falsifies the Davson-Danielli model?

• the presence of globular proteins in the lipid bilayer

• Membrane proteins remain fixed in position

• there are two layers of phospholipids

• electron micrograph that is similar to a railroad track

What is this model of membrane structure?

• Singer-Nicolson model

• Davson-Danielli model

• Gorter and Grendel model

• Lipoprotein sandwich model

What did Gorter and Grendel find out that helped them propose their model?

• the area occupied by lipid bilayer

• the area occupied by a lipid monolayer

• the area of the cell

• the concentration of red blood cells

What do you call the technique that involves rapid freezing of cells and then fracturing them to see the internal structures?

• fracture method

• freeze method

• freeze fracture method

• frozen cell method

Which model of membrane structure is shown in the picture?

• Gorter and Grendel model

• Davson-Danielli model

• Singer-Nicolson model

• Fluid mosaic model

Which is NOT a function of membrane proteins?

• hormone binding sites

• channels and pumps for transport

• cell adhesion

• protein synthesis

True or False: Membrane proteins vary in number in different cell membranes.

• True

• False

Which is NOT a function of the phospholipid bilayer?

• creates a barrier

• semi-permeability of the membrane

• transport of molecules

• separates internal from external environment of the cell

What do you call the property of phospholipids having both hydrophilic and hydrophobic parts?

• amphiphilic

• amphiphatic

• semipermeability

• selective

Which is the role of cholesterol in cell membranes?

• communication between cells

• control of transport

• control of fluidity of membrane

• enhances the fluidity of the membrane