Biol-102: Lab 02: Diffusion

Front 1

define: kinetic energy

Back 1

The energy an object posses due to its motion

Front 2

define: diffusion

Back 2

as the movement of molecules from an areas of high concentration to an area of low concentration

Front 3

What are a few factors what would affect the rate of diffusion in molecules?

Back 3

1. temperature
2. "steepness" of the concentration gradient
3. membrane surface area
4. permeability of the plasma membrane to the substrate

Front 4

define: osmosis

Back 4

the movement of water from an area of high concentration to an area of low concentration
• refers to the movement of water across a biological membrane

Front 5

True/False: The biological membrane surround the cell and divides the inside of the cell from the outside.

Back 5

TRUE

Front 6

True/False: The plasma membrane is impermeable.

Back 6

FALSE

Front 7

True/False: The plasma membrane is semipermeable.

Back 7

TRUE

Front 8

Chemically the cell membrane is made up of a ___.

Back 8

phospholipid bilayer

Front 9

Water can pass through the cell membrane via ___.

Back 9

passive transport

Front 10

Some substances (such a glucose) require energy to move across the cell membrane in a process called ___.

Back 10

active transport

Front 11

define: solute

Back 11

substance that can dissolve in a liquid (example: sugar, flavorings)

Front 12

define: solvent

Back 12

liquid that can dissolve solutes (example: water)

Front 13

define: solution

Back 13

solvent with solute(s) dissolved (example: soda pop)

Front 14

What are the three terms associated with osmosis?

Back 14

hypotonic, isotonic and hypertonic

Front 15

The internal environment of the cell (cytosol) is known as the ___.

Back 15

intracellular fluid (ICF)

Front 16

The external environment of the cell is known as the ___.

Back 16

extracellular fluid (ECF)

Front 17

define: hypotonic solution

Back 17

(hypotonic ECF) contains a lower concentration of solutes than the cytoplasm (cytosol) of the cell's internal environment (ICF)

Front 18

define: isotonic solution

Back 18

contains the same concentration of solutes as the cytosol of the cell

Front 19

define: hypertonic solution

Back 19

(hypertonic ECF) contains a higher concentration of solutes than the cytosol of the cell

Front 20

Hypotonic, isotonic and hypertonic are always a comparison of the ___ in the ECF to the concentration of solutes in the ICF or vice-versa.

Back 20

concentration of solutes

Front 21

define: hypertonic

Back 21

has a higher concentration of solutes than the cytosol of the cell
• Having a higher concentration of solutes in the external environment equates to having a lower concentration of water than the cytosol of the cell. This means that the water will flow form the inside of the cell to the outside of the cell. The cell will lose water. The cell will dehydrate. The cell will shrink.

Front 22

define: hypotonic

Back 22

has a lower concentration of solutes than the cytosol of the cell.
• Having a lower concentration of solutes in the external environment equates to having a higher concentration of water than the cytosol of the cell. This means that the water will flow from the outside of the cell to the inside of the cell. The cell will gain water. This cell will swell and may burst.

Front 23

define: isotonic

Back 23

has the same concentration of solutes in the environment as the cytosol of the cell.
• Having the same concentration of solutes in the external environment equates to having the same concentration of water as the cytosol of the cell. In an isotonic condition, water still moves. However in this case, one water molecule will exit as another molecule of water enters the cell. There will not be any net movement of water.

Front 24

If the ECF of a cell were considered to by hypotonic, the ICF of the cell would be considered ___.

Back 24

hypertonic

Front 25

If the ECF of a cell has a lower concentration of water than the cytosol, what osmotic term would be used to describe the ECF?

Back 25

hypertonic

Front 26

If the cytosol of a cell contained 60% solutes and therefore 40% water, would water enter or exit the cell if the cell were placed into an ECF that contained 75% solutes and 25% water?

Back 26

water would exit the cell

Front 27

If a million cells had a mass of 0.002mg and were placed into a hypertonic ECF, the mass might change to ___.

Back 27

0.001mg