d2.3

Flashcards covering key concepts from the lecture on water potential and its movement in biological systems.

What is the structure of a water molecule?

A water molecule consists of 2 hydrogen atoms covalently bonded to 1 oxygen atom.

What property of water arises from its dipolar nature?

The partial charges due to oxygen being more electronegative cause water to form hydrogen bonds.

What are hydration shells?

Hydration shells are layers of water molecules that surround and separate ions, facilitating their dissolution.

What is the definition of solute?

A solute is a substance that dissolves in water.

What is osmosis?

Osmosis is the movement of water across a selectively permeable membrane from low solute concentration to high solute concentration.

What occurs in a hypertonic solution relative to a cell?

Water moves out of the cell, causing it to shrink (crenation in animal cells and plasmolysis in plant cells).

What are isotonic solutions?

Isotonic solutions have equal solute concentrations, resulting in no net water movement and maintaining dynamic equilibrium.

What are the effects of a hypotonic solution on animal and plant cells?

In a hypotonic solution, water moves into the cell, causing animal cells to swell and possibly burst (lysis), while plant cells swell but do not burst due to their cell wall.

What is turgor pressure in plant cells?

Turgor pressure is the pressure exerted by the cytoplasm against the cell wall, increasing when water enters the cell by osmosis.

How does water potential influence water movement?

Water moves from areas of higher water potential to lower water potential until equilibrium is reached.

What is the relationship between solute potential and water potential?

Solute potential lowers water potential; the presence of solutes decreases the number of free water molecules.

What happens to plant tissue in a hypertonic solution?

Plant tissue loses mass and length as water moves out, leading to plasmolysis.

What is the purpose of isotonic solutions in medical applications?

Isotonic solutions prevent water loss or gain by osmosis and help provide nutrients and oxygen during organ preservation.

What happens to cells that lack a cell wall in hypotonic solutions?

Cells swell and may burst due to excess water entry.

What is the effect of pressure potential on water movement?

Positive pressure potential increases water potential, while negative pressure potential decreases it.