AP Biology Tonicity

Front

What is tonicity?

Back

Tonicity refers to the ability of a surrounding solution to cause a cell to gain or lose water. It is determined by the concentration of solutes in the solution compared to the concentration of solutes inside the cell.

Front

What happens to a cell in a hypotonic solution?

Back

In a hypotonic solution, water enters the cell, causing it to swell and potentially burst due to the increased internal pressure.

Front

What is the difference between passive transport and active transport?

Back

Passive transport is the movement of materials across a cell membrane without the use of energy, moving from high to low concentration. Active transport requires energy to move materials against their concentration gradient, from low to high concentration.

Front

What role does the cell membrane play in cellular transport?

Back

The cell membrane regulates what enters and leaves the cell, maintaining homeostasis by controlling the movement of substances.

Front

What is an example of a protein channel involved in passive transport?

Back

An example of a protein channel involved in passive transport is aquaporin, which facilitates the movement of water across the cell membrane.

Front

What is the Na/K pump and how does it function?

Back

The Na/K pump is an example of active transport that moves sodium ions out of the cell and potassium ions into the cell, using ATP to maintain the electrochemical gradient.

Front

What occurs in a hypertonic solution?

Back

In a hypertonic solution, water leaves the cell, causing it to shrink or crenate due to the higher concentration of solutes outside the cell.

Front

How does osmosis differ from diffusion?

Back

Osmosis is the specific movement of water across a selectively permeable membrane, while diffusion refers to the movement of solutes from an area of high concentration to an area of low concentration.

Front

What is the significance of solute concentration in determining tonicity?

Back

The concentration of solutes in a solution determines its tonicity, which affects the direction of water movement across the cell membrane.

Front

What is a selectively permeable membrane?

Back

A selectively permeable membrane is a barrier that allows certain substances to pass while blocking others, crucial for maintaining cellular homeostasis.