Cell Membrane Basics (Version A)

Which type of biological macromolecule is the main component of the plasma membrane?

• carbohydrate

• lipid

• protein

• nucleic acid

Answer explanation

The main component of the plasma membrane is a lipid, making it a lipid bilayer that provides structure and regulates what enters and exits the cell.

What is NOT TRUE about the cell membrane?

• It controls what enters and leaves the cell

• Semipermeable

• Phospholipid bilayer

• Contains digestive enzymes

Answer explanation

The cell membrane does not contain digestive enzymes, making this statement not true.

Define plasma membrane

• lipid that helps minimize effects of temperature

• only on the outer surface of the plasma membrane and are attached to proteins or lipids; form distinctive cellular markers

• flexible boundary of a cell that separates a cell from its surroundings

• may extend partway into the plasma membrane, cross the membrane entirely, or be loosely attached to its inside or outside face

Answer explanation

The plasma membrane is the flexible boundary of a cell that separates a cell from its surroundings, which is the correct definition provided.

What forms the channels and pumps in the phospholipid bilayer?

• carbohydrates

• proteins

• hydrophilic heads 

• lipids

Answer explanation

Proteins form the channels and pumps in the phospholipid bilayer.

Which statement best describes the cell membrane?

• The protective outer layer that controls what enters and leaves the cell.
  

• Stores information on DNA molecules / Directs and controls the activities of the cell.
  

• A folded membrane that moves materials around inside cells / Also acts as the site of manufacturing materials needed by the cell.
  

• The smallest organelle with a huge job / Makes proteins, which are the building blocks of the body.
  

Answer explanation

The cell membrane is the protective outer layer that controls what enters and leaves the cell, making it the best description among the options provided.

Tags

NGSS.MS-LS1-2

True or false:  Regulating what enters and leaves the cell helps the cell maintain homeostasis. 

• True

• False

Answer explanation

Regulating what enters and leaves the cell helps maintain homeostasis by controlling the internal environment of the cell.

Tags

NGSS.HS-LS1-3

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

• Selectively (or Semi) Permeable 

• Totally Transparent

• Liquid Licorice 

• Heavily Patrolled 

Answer explanation

Something is selectively (or semi) permeable when some molecules can cross the membrane while others cannot.

The cell membrane is selectively permeable, which means...

• All materials can enter and leave the cell

• Certain things can enter while others cannot

• The cell manually sorts through all materials

• Only certain cells can interact with the cell.

Answer explanation

The cell membrane is selectively permeable, which means certain things can enter while others cannot.

This cell organelle helps organisms maintain homeostasis by controlling what substances may enter or leave cells.

• vacuole

• nucleus

• cell membrane

• cell wall

Answer explanation

The cell membrane helps organisms maintain homeostasis by controlling what substances may enter or leave cells.

Tags

NGSS.HS-LS1-3

A phospholipid has 2 parts. What are they called? 

• Hydrophilic Head, Hydrophobic Tail 

• Hydrophobic Head, Hydrophilic Tail 

Answer explanation

The two parts of a phospholipid are the Hydrophilic Head and the Hydrophobic Tail.