D 2.3: Water Potential

Solvation

The process of dissolving.

Solvents

Are liquids that can dissolve other substances to make solutions.

Solutes

Are dissolved substances in solutions.

Osmosis

Is a net movement of water across a membrane due to the attractions between solutes and water.

Diffusion

When solute goes from a state of low to high concentration.

Hypertonic solution

High solute concentration saturated with solutes - water moves into the solution.

Hypotonic solutions

Low solute concentration relative to a substance, not all saturated with solutes.

Isotonic solution

Net movement: equal amounts of solute concentrations in and out, same solute concentration as the cells inside them.

Net Movement

There is no net movement of water into or out of an isotonic solution, so cells inside do not have an change in volume.

Crenation

Is when a cell loses water and shrinks.

Cohesion

Is when water molecules stick together due to their tendency to make hydrogen bonds with other water molecules.

Adhesion

Is when water molecules stick to other (polar but non-water) surfaces due to hydrogen bonds.

Amphipathic

Molecules contain both polar and nonpolar components (hydrophilic and hydrophobic parts).

Surface tension

Is a property of water that allows it to resist an external force; water has a very high surface tension.

Capillary action

Is the movement of water through a narrow space, often in opposition to external forces like gravity.

Ideal temperature conditions for liquid water

A planet needs to be in the goldilocks zone, with temperatures between 0-100 degrees.

Factors for a planet to retain water

1.) A strong gravitational pull due to planet size; 2.) Intensity of sunlight due to planet's distance from the sun.

How did water end up on earth?

The leading hypothesis is that ice-containing asteroids collided with earth; the ice melted adding to the growing volume of liquid water in our oceans.

Animal cells in a Hypotonic solution

Animal cells may burst if too much water enters.

Animal cells in a Hypertonic solution

Crenation is when a cell loses water and shrinks.