Cell Membrane and Transport

Phospholipid molecules have a 'head' region that contains a phosphate group and a 'tail' region composed of two hydrocarbon chains. Which term correctly describes the properties of the phosphate head?

• Hydrophillic

• Agoraphobic

• Hydrophobic

• Amphipathic

Which molecules can not cross the phospholipid bilayer by diffusion?

• small, polar molecules (e.g. water, ethanol)

• large, polar molecules (e.g. glucose)

• hydrophobic molecules (e.g. benzene)

• small, non-polar (carbon dioxide, oxygen)

Diffusion is...

• when a substance is present in equal concentrations on both sides of a membrane

• the movement of a substance from an area of low concentration to an area of high concentration

• the movement of a substance from an area of high concentration to an area of low concentration

• the speed at which molecules move across a biological membrane

Select the correct description of the location of a peripheral protein within a plasma membrane.

• embedded in the hydrophobic layers of the plasma phospholipid bilayer

• attached to one surface of the phospholipid bilayer

Which of the following are possible functions of membrane proteins?

• communication

• adhesion

• transport

• receptor

During active transport, a substance is moved

• From high to low concentration by a carrier protein

• From low to high concentration by a carrier protein

• From high to low concentration through the phospholipid bilayer

• From low to high concentration through the phospholipid bilayer

Which is true about active transport?

• It requires energy

• it does not require energy

• It moves substances down the concentration gradient

• it moves material from high to low concentration

What is the function of a cell’s selectively permeable membrane?

• It helps the cell to manufacture proteins.

• It regulates the amount of ATP the cell produces.

• It regulates what materials enter and leave the cell.

• It packages and stores most of the material in a cell.

Tags

NGSS.MS-LS1-2

A cell membrane is ___________ ____________ when some molecules can cross the membrane while others cannot. 

This egg has shrunk, what type of solution was it placed in?

• tap water

• salt water

• distilled water