Lab 4 - Diffusion and Osmosis

This set of flashcards covers key concepts related to diffusion, osmosis, and active transport as discussed in lab 4.

What is diffusion?

Movement of molecules down their concentration gradient, occurring spontaneously without the need for energy.

What particles can cross the plasma membrane?

Lipophilic (non-polar) small molecules like O2, CO2, and Steroids.

What particles cannot cross the plasma membrane?

Hydrophilic (polar or charged) molecules, macromolecules, glucose, ions, and H2O.

What is facilitated diffusion?

Passive movement of particles that require membrane proteins to help them cross the plasma membrane.

What is active transport?

Transport that occurs against the concentration gradient and requires energy.

What is osmosis?

Passive movement of water across a selectively permeable membrane.

How does osmolarity affect cells?

Osmolarity is the concentration of all impermeable solutes; it affects whether cells gain or lose water.

What does isotonic mean?

A solution that has the same osmotic pressure as the inside of the cell, resulting in no net movement of water.

What happens in a hypotonic solution?

The solution surrounding the cell has a lower concentration of solutes, which can lead to cell swelling or bursting.

What is osmotic pressure?

The pressure required to stop the net movement of water across a selectively permeable membrane.