Ch. 4 Diffusion/Osmosis Flashcards
Solution (2)
• homogeneous mixture (particles are distributes evenly throughout)
(Gases, liquids, and solids all form solutions)
(An alloy of metals is a common metallic solution)
solutions are composed of ________ known as _________and_________
2 phases:
Solvent and solute
Solvent
Most abundant phase
Solute
- the phase present in the lesser amount
* dissolves in solvent
Alloy
A solution of 2 or more metals
Ex: steel
Dynamic equilibrium
The equilibrium is considered dynamic since there is still movement of molecules but their distribution remains balanced
Diffusion
- no energy required
* goes from high concentration to low concentration
Concentration gradient
Movement is “down a concentration radiant” since the molecules move from areas of higher concentration to areas of low concentration
Agar (3)
Gel - like substance
extracted from seaweed
often used in laboratory experiments
A MOLE of substance is ________
The amount of a substance equal to the molecular mass of that substance (expressed in grams)
Total amount of a substance = molecular mass
Molecular mass
Determined by adding the atomic mass of each element in a compound
Osmosis (5)
- definition
- form of _______
- ________ process
- requires ____ energy
- follows the ________ of molecules
• the movement of WATER molecules across a plasma membrane
- form of diffusion
- passive process (like diffusion)
- requires no energy
- follows the concentration gradient of water molecules
Tonicity
Used when COMPARING THE CONCENTRATION OF SOLUTES inside and outside the plasma membrane
Hypotonic
Environment exists outside the cell when the solute concentration outside the cell is lower than the solute concentration in the the cells cytoplasm
• when the concentration outside is LOWER than inside
- swells
- “blows up like a hypo”
Hypertonic
When the solute concentration outside the cell is higher than that inside the cell
• when the concentration outside is HIGHER than the inside
“Hyper” - high amount of solute
- shrinks
Hypothesis
- prediction
- first step in the scientific method
Scientific method
- procedures and waiting time are the experiment part
Conclusion of the scientific method
Relate to the hypothesis
- either uphold or discount the prediction
Differently / selectively permeable
only certain materials can move across them
Plasma membrane ***
In animals the plasma membrane is usually the outermost limit of the cell
- have fairly rigid cell wells
- made of cellulose as their outer limit
- the plasma membrane immediately interior
- (like blood cells) if they have no protective cell wall and will swell and burst (process called lysis) under hypotonic conditions
- plant cells central vacuole will fill and press the plasma membrane against the interior of the cell wall
Turgid **
The cells condition
Turgor pressure
The resulting water pressure
Plasmolysis
in hypertonic conditions:
- an animal cell will shrink
- a plant cell undergoes plasmolysis as its plasma membrane is pulled away from the cell wall when the central vacuole is emptied