Cell membranes STUDENT.pdf: BIOL-120-01 (22170.202601)

What is the primary structure of a cell membrane?

A phospholipid bilayer.

What molecules are embedded within the phospholipid bilayer?

Proteins.

What is the main function of cell membranes?

To control the movement of substances in and out of cells.

What term describes the fluid nature of cell membranes?

Fluid mosaic model.

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

Small, nonpolar molecules.

What do we call molecules that are both hydrophobic and hydrophilic?

Amphipathic molecules.

What is the role of cholesterol in cell membranes?

To maintain membrane fluidity.

What are glycoproteins and glycolipids involved in?

Cell recognition and signaling.

What does selective permeability mean?

Only certain substances can pass through the membrane.

What is the difference between passive and active transport?

Passive transport does not require energy; active transport does.

What is osmosis?

The diffusion of water across a selectively permeable membrane.

What does hypertonic mean in relation to a cell?

A solution with a higher concentration of solutes compared to the cell.

What is a hypotonic solution?

A solution with a lower concentration of solutes compared to the cell.

What happens to a cell in isotonic solution?

The cell remains the same, as the concentration is balanced.

What is facilitated diffusion?

Transport of substances across a membrane via proteins without energy.

What are channel proteins?

Proteins that provide passageways for specific substances.

What are carrier proteins?

Proteins that change shape to transport substances across the membrane.

What is endocytosis?

The process by which a cell takes in material by engulfing it.

What is exocytosis?

The process by which a cell expels material in vesicles.

What is the function of the sodium-potassium pump?

To transport sodium out of and potassium into the cell.

What is membrane potential?

The difference in charge across a membrane.

What are receptors in the context of cell membranes?

Proteins that bind signaling molecules.

What is signal transduction?

The process through which a cell responds to signals.

What role do membranes play in apoptosis?

They can release signals that trigger programmed cell death.

What is the extracellular matrix?

A network that provides structural and biochemical support to surrounding cells.

What is the importance of membrane fluidity?

It allows for the movement and functioning of proteins and lipids.