d2.3 water potential Flashcards
(20 cards)
What is a solvent and a solute in a solution?
The solvent dissolves substances, while solutes are the dissolved particles.
What is solvation?
The process by which solvent molecules surround and interact with solute particles.
Why can water dissolve charged and polar molecules?
Water is polar, allowing it to form hydrogen bonds with other polar and charged molecules.
What is osmolarity?
The concentration of solute particles in a solution.
How do hydrophilic and hydrophobic substances interact with water?
- Hydrophilic substances dissolve in water due to polarity.
- Hydrophobic substances repel water and do not dissolve.
Define isotonic, hypotonic, and hypertonic solutions.
- Isotonic: Same solute concentration as the cell.
- Hypotonic: Lower solute concentration than the cell.
- Hypertonic: Higher solute concentration than the cell.
What is the unit for solute concentration in a solution?
Molarity (M), osmolarity (Osm), or percentage concentration.
What is the net movement of water between different solution types?
- Water moves into the cell in hypotonic solutions.
- Water moves out of the cell in hypertonic solutions.
- No net movement in isotonic solutions.
What is osmosis?
The passive movement of water across a membrane from low solute concentration to high solute concentration.
Is osmosis passive or active transport?
Passive transport—no energy required.
What happens to cells placed in isotonic, hypotonic, and hypertonic solutions?
- Isotonic: Normal shape, no net water movement.
- Hypotonic: Water enters, cells may burst (lysis in animal cells).
- Hypertonic: Water exits, cells shrink (crenation in animal cells).
How does plant tissue mass change in hypotonic vs. hypertonic solutions?
- Hypotonic: Water enters, tissue swells and becomes turgid.
- Hypertonic: Water exits, tissue shrinks and undergoes plasmolysis.
How can solute concentration in plant tissue be determined?
By measuring mass or length changes in different tonicity solutions.
How do hypertonic and hypotonic solutions affect animal cells?
- Hypertonic: Cells lose water and shrink (crenation).
- Hypotonic: Cells absorb water and may burst (lysis).
What is the function of the contractile vacuole in freshwater unicellular organisms?
Pumps out excess water to maintain osmotic balance.
Why must tissue fluid be isotonic to surrounding cells?
To prevent excessive water loss or gain, ensuring cell stability.
What are the strength and permeability properties of a cell wall?
- Provides structural support.
- Allows passage of water and some solutes.
How do hypertonic and hypotonic solutions affect plant cells?
- Hypotonic: Water enters, cell becomes turgid (rigid).
- Hypertonic: Water leaves, plasmolysis occurs (membrane pulls away).
What effects do isotonic, hypertonic, and hypotonic solutions have on human cells?
- Isotonic: Maintains balance without shrinking or swelling.
- Hypotonic: Causes swelling; dangerous in excess.
- Hypertonic: Causes shrinkage; used to reduce swelling.
What is “normal saline” used for in medical procedures?
An isotonic solution used for IV therapy, hydration, and wound cleaning.
