1. What is Water Potential?

Water potential (Ψ) is a measure of the potential energy of water per unit volume relative to pure water. It helps us understand how water moves in plants and soil. The total water potential is the sum of solute potential (Ψ_s) and pressure potential (Ψ_p).

2. How Does the Calculator Work?

The calculator uses the water potential equation:

Where:

• \( \Psi \) — Total water potential (bars)
• \( \Psi_s \) — Solute potential (bars, usually negative)
• \( \Psi_p \) — Pressure potential (bars, usually positive)

Explanation: Water always moves from areas of higher water potential to lower water potential. This simple equation helps us predict water movement in biological systems.

3. Importance of Water Potential

Details: Understanding water potential is crucial for studying how plants take up water from soil, how water moves through plants, and how cells maintain their shape through turgor pressure.

4. Using the Calculator

Tips: Enter both solute potential and pressure potential in bars. The calculator will add them together to give you the total water potential.

5. Frequently Asked Questions (FAQ)

Q1: Why is solute potential usually negative?
A: Solute potential is negative because dissolved substances reduce the potential energy of water compared to pure water.

Q2: What is a typical water potential value for plant cells?
A: Most plant cells have a water potential between -1 to -3 bars when fully turgid.

Q3: How does water potential explain wilting?
A: When a plant's water potential becomes more negative than the soil's, water can't move into the plant, causing wilting.

Q4: Can water potential be positive?
A: Yes, in systems with high pressure (like water in a hose), the pressure potential can make the total water potential positive.

Q5: How is this different from osmosis?
A: Water potential is the measurement that drives osmosis - water moves from high to low water potential.