Cell Membrane Processes: Diffusion and Osmosis

Flashcards summarizing key concepts related to diffusion and osmosis at the cell membrane.

What is osmosis?

Osmosis is the diffusion of water.

What happens in diffusion?

Molecules move from an area of high concentration to low concentration.

What is a solute?

A substance that is dissolved within a solution.

What is a solvent?

The material doing the dissolving, often water.

What do you call a combination of a solute and a solvent?

A solution.

What happens to the concentration of a solution if you add more solute?

The concentration of the solution increases.

What is a concentration gradient?

The difference in concentration between two areas.

What is Brownian motion?

The idea that all molecules are always in motion.

Why is diffusion considered an energy-free process?

Because it occurs due to random particle motion and requires no external energy.

What is equilibrium in the context of diffusion?

The state where the concentration of solutes is even throughout a system.

How does oxygen move into our bloodstream?

Oxygen diffuses from the lungs into the bloodstream where there is a lower concentration of oxygen.

What typically drives water movement during osmosis?

Water moves from a region of lower solute concentration to higher solute concentration.

What is the effect of adding water to a concentrated solution?

It dilutes the concentration of the solution.

What drives molecules to move across a semipermeable membrane?

Brownian motion and concentration gradients.

In the context of cell membranes, what is meant by 'semipermeable'?

It allows certain molecules to pass while blocking others.

What do students often learn about diffusion with the example of food coloring?

A drop of food coloring in water will spread out to become evenly distributed.

What is an everyday example of diffusion?

The spreading of perfume scent in a room.

Why is diffusion important for living organisms?

It enables essential substances like oxygen to move without energy expenditure.

What happens during the process of reaching equilibrium?

Molecules will move back and forth equally, maintaining balanced concentrations.

What happens if a molecule is too large to pass through a membrane?

Water will move instead, affecting the concentration on either side.

How does temperature affect diffusion?

Higher temperatures typically increase the speed of diffusion.

What role does random particle movement play in diffusion and osmosis?

It is the mechanism that drives the movement of molecules and water.

How might students experience diffusion during a classroom activity?

By mimicking random motion and 'colliding' to reach an even distribution.

What biological process exemplifies diffusion and osmosis in action?

Gas exchange in the lungs.

What concept explains why molecules continue to move even after reaching equilibrium?

Brownian motion keeps the molecules in constant movement.

What are two main processes discussed in the lecture related to cell membranes?

Diffusion and osmosis.