Plasma Membrane

Front

What is the plasma membrane?

Back

The plasma membrane is a biological membrane that separates and protects the interior of all cells from the external environment. It is composed of a phospholipid bilayer with embedded proteins.

Front

What does it mean for a plasma membrane to be selectively permeable?

Back

It means that the plasma membrane regulates what substances can enter or leave the cell, allowing some molecules to pass while blocking others.

Front

What type of molecules can easily pass through the plasma membrane?

Back

Small, nonpolar, hydrophobic molecules such as fatty acids can easily pass through the membrane's bilayer.

Front

What are phospholipids?

Back

Phospholipids are molecules that make up the plasma membrane, consisting of a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails.

Front

What is the role of cholesterol in the plasma membrane?

Back

Cholesterol helps to stabilize the structure of the plasma membrane and maintain its fluidity.

Front

What are cell surface carbohydrates?

Back

Cell surface carbohydrates are molecules found on the outer surface of the plasma membrane that play a key role in cell recognition and communication.

Front

What is the hydrophilic part of a phospholipid?

Back

The hydrophilic part of a phospholipid is the polar head, which is attracted to water.

Front

What is the hydrophobic part of a phospholipid?

Back

The hydrophobic part of a phospholipid consists of two nonpolar tails that repel water.

Front

How do transport proteins function in the plasma membrane?

Back

Transport proteins facilitate the movement of substances across the plasma membrane that cannot easily pass through the lipid bilayer.

Front

What is endocytosis?

Back

Endocytosis is the process by which cells engulf substances from the outside environment, bringing them into the cell.