Biology Lab #5

isotonic

(used of solutions Iso = same) having the same or equal osmotic pressure No need to equalize pressure cause it is already equal

Absolute zero

-273 degrees C

Viscosity

A liquid's resistance to flowing - a more viscous (thicker) solution like corn syrup flows less easily then a less viscous one (like salt water)

Particles in motion?

All particles (atoms and/or molecules) are in constant, random motion at temperatures above absolute zero (-273°C)

Lampblack particles moved around

Brownian movement - particles moved around because the molecules of soap & water collided

Solution

Gas into another gas Liquid solution formed by dissolving a

3 states in which pure chemicals exist

Solid Liquid Gas

Brownian Movement

The constant, random, zigzag movement of small particles dispersed in a fluid medium, caused by collision with molecules of the fluid.

Solute

The substance that is dissolved

molecular weight

The sum of the weights of all the atoms in a molecule.

Solvent

a liquid substance capable of dissolving other substances

molarity

concentration measured by the number of moles of solute per liter of solvent

plasmosis

contraction or shrinking of the cell membrane of a plant cell in a hypertonic solution in response to the loss of water by osmosis

osmosis

diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal

hypertonic

hyper - above (more particles) having a higher concentration of solute than another solution Water will leave the cell to equalize pressure

hypotonic

hypo=lender (less particles) describes a solution whose solute concentration is lower than the solute concentration inside a cell If you want to hydrate a cell, you dehydrate it

Diffusion

process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated

dialysis

separation of substances in solution by means of their unequal diffusion through semipermeable membranes Starch molecules too big to go thru the bag, sodium hydroxide is small enough to pass through the bag and stain the phenolphthalein

effect of temperature in the rate of diffusion

the higher the temperature, the faster the diffusion

rate of diffusion in gasses

the more concentrated the higher the rate of diffusion - open a bottle of perfume and eventually the smell will permeate the whole room

turgor pressure

the pressure that water molecules exert against the cell wall. too much and it will burst

rate of diffusion in agar

the side with the methylene blue diffuses slower because there is a great weight of methylene blue The lower the weight, the fast the diffusion

Concentration

the strength of a solution

passive transport

transport of a substance across a cell membrane by diffusion

inversely proportional

two items are associated such that when one item increases the other item decreases - so when viscosity and molecular weight increase the diffusion decreases