Membrane Structure and Function (Ch 7, U 2)

The cell membrane is...

• a phospholipid bilayer

• a phospholipid trilayer

• a protein bilayer

• two stranded molecule

Cell membranes are mainly composed of... (select all that apply)

• carbohydrates

• proteins

• phospholipids

• cholesterol

The ____ is hydrophobic

• tail

• head

T or F: Passive transport requires energy

• True

• False

The concentration gradient is...

• high -> high

• low -> high

• low -> low

• high -> low

Why does active transport require energy?

• the molecules being transported are too big

• it goes against the concentration gradient

• it is a faster way of transporting molecules

• there are too many substances being transported

T or F: Exocytosis is when material is released into the extracellular environment

• True

• False

Cytosis is the transport of which type of molecules?

• hydrophillic

• charged

• bulk

• ATP

What does "fluid" mean in the fluid mosaic model?

• that there is constant fluid flowing into and out of the membrane

• that the membrane flows around the cell

• that there is a lot of extracellular liquid surrounding the membrane

• that components move freely in the cell membrane

Select the two types of passive transport

• simple diffusion

• sodium-pottasium pump

• facilitated transport

• ATP hydrolosis