Cell membranes Ck-12

Which cell structure is made of a bilayer of phospholipids and encloses all cells?

• cytoskeleton

• cell membrane

• cytoplasm

• cell wall

Which statement about the cell membrane is false?

• The tails of the cell membrane are hydrophobic.

• The cell membrane is made primarily of carbohydrates.

• The cell membrane has two layers.

• The cell membrane is semipermeable.

A ___________

is a lipid molecule with a hydrophilic head and two hydrophobic tails.

The cells of all organisms are separated from the outside by a __________

The cell membrane mainly consists of DNA.

• True

• False

The tails of phospholipid molecules in the cell membrane are hydrophobic.

• True

• False

The middle of the cell membrane bilayer is an area without water.

• True

• False

The cell membrane _____________.

• has hydrophobic tails on the exterior

• is semipermeable

• has three layers

What term refers to the part of the cell that includes the cytosol and all organelles (except the nucleus)?

• cytosol

• cytoplasm

• cell membrane

What is a phospholipid molecule made of?

• a hydrophilic head and hydrophobic tails

• a hydrophobic head and hydrophobic tails

• a hydrophilic head and hydrophilic tails

• a cytosol and a cytoplasm