Diffusion Lab Notes Reviewing the State Lab. What can we conclude from this lab exercise? The cell...

Diffusion Lab Notes

Reviewing the State Lab

What can we conclude from this lab exercise?

• The cell membrane regulates what goes in and out of the cell

• Small or simple molecules pass easily through the cell membrane

• The diffusion of water into and out of the cell is called osmosis

• If too much water leaves the cell, it shrinks

How do we know this?

• Created cell to model osmosis and cell turned blue black because iodine went into the cell

• Cell watery environment had glucose in it-turned milky orange in presence of Benedicts

• Onion cell shrunk in salt water and went back to original size after rinsed

Other Facts

• Indicator- a chemical that reacts with another chemical and makes the color change indicating its presence

• Lugol’s-indicates the presence of starch, turns blue black

• Benedict’s Solution- indicates the presence of glucose-turns milky orange when heated

What kind of molecules can pass through membrane easily?

• Simple ones-ex: glucose• Water

• Large complex molecules do not- ex: Starch

What determines whether salt solution or water enters the cell?

• The concentration of water must be greater either inside or outside for water to leave or enter

• Water will move from high to low

Osmosis

Concentration inside

Concentration outside

Water will Cell will

High Low Leave Shrink-Hypertonic

Low High Enter Grow and may explode-hypotonic

Equal to outside Equal to inside Stay same Maintain balance orEquilibrium-isotonic