diffusion osmosis report.docx

8/9/2019 DIFFUSION OSMOSIS REPORT.docx

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University of Balamand

Faculty of Sciences

Department of Biology

General Biology 1 Laboratory

BIOL 22

!"periment #$ Di%usion &nd Osmosis

Date$ 11'11'21(

Submitted to$ )s* +amela )el,i

Submitted by$ Step-anie Da-r &1.11(

/ac-elle Diab &1(110

Introduction:


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* 6ndocytosis: the phenomenon where the cells ta(es in large particles and

ingests them% + type of endocytosis is phagocytosis% This is when a cell ta(es

in and digest an ob7ect%

* 4embrane carrier proteins: - 8acilitated diusion !down the gradient" from

high to low concentration" and no energy required#%

- rotein channels! passage of insoluble to

lipid molecules through the membrane" no energy required#

- +ctive transport! down and up the gradient"

and require energy#" ex: sodium-potassium pump%

!"ercise #*1$ -e mec-anism of Di%usion:

* In this exercise we are supposed to see the 7iggling of individual molecules%

)aterials: - Toothpic(

- )ropper bottle of water

- 2armine dye powder

- lide 9 2overslip

- 2ompound 4icroscope

* +rocedure$

- e obtained a clean slide and a coverslip

'- e placed ' drops of water on the slide

;- Then" we used a toothpic( to remove a small amount of powder from the

mother sample" and then we tapped the toothpic( on the slide !water part#%


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- ,n the low power ob7ective:

e were not able to see the particles of neither the water nor the carmine

dye moving%

> ,n the high power ob7ective:

- e can obviously see that the carmine dye powder is insoluble in water

!Tiny bits of the powder are suspended in the water%

'-e were able to see the red granules vibrating or ? 7iggling?%

This movement is called &rownian movement% This movement is due to the

invisible particles of water that are vibrating" and colliding with each other

and the red granules%

*ost @ab Auestions:

- The carmine particles move randomly due to the bombardment of the

particles by the Binvisible? water molecules%

'- I cannot see the water molecules% 3owever" I can tell that they are

moving% +s long as the temperature is above 5ero" the molecules are always

on the move !constant motion#%

;- The movement of carmine particles is due to bombardment by water

molecules%


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C- + change in medium ! from water to gelatin# would cause the rate of

diusion to slow down%

!"ercise #*2 3 -e e%ect of emperature On Di%usion:

*In this experiment" we will see how the rate of diusion is aected by the

temperature%

)aterials$ -Two clean test tubes

-Test tube rac(

-+ dropper

-8orceps

-otassium permanganate

-' mother solutions ! with hot water and the other with cold

water#%

+rocedure$

- e obtained ' clean test tubes from a test tube rac(

'- lled about half the test tube with hot water and the other lled also

about half the other test tube with cold water ! using a dropper#%

;- Dsing forceps" we both placed the same small amount of potassium

permanganate ! powder# at the same time in the test tubes" and we

observed the ndings%

/esults$

In this picture" we can see that the potassium permanganate is mixed with

the hot water better than with the cold water% In the hot water we almosthave color in all the tube" while in the cold water" the potassium

permanganate is ta(ing more time to mix with all the regions of the water in

the tube%

Therefore" we can conclude that when the temperature augments" the rate

of diusion augments%


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* ost-@ab Auestions:

E- +fter three minutes" the diusion in the tube with hot water is the

greatest%

F- The temperature of the tube with greatest diusion increases the

molecular motion of the water and potassium permanganate%

/- Ges" the tube with least diusion will eventually reach the same state as

the tube with greatest diusion because the temperature only ma(es the

rate of diusion faster%

* !"periment #*( 3 Osmosis$ 4Involves only 5ater di%usion6

* we chose potato for this experiment because it gives the fastest results%

* In this experiment we are supposed to see a change in the si5e and shape

of the potato cylinders%

)aterials: - half a cut potato !to get / potato cylinders#

- '.0 1a2l solution ! hypertonic#

- .%/0 1a2l solution ! isotonic#

- )istilled water !less than .%/0 1a2lH hypotonic#

- 8orceps

- uler

- aper towels

- 2or( &orer

- &alance

- etri dishes !with their cover#

+rocedure$


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- e cut / potato cylinders using the ?2or( &orer? and placed them on a

etri dish cover% Then" we evened them out using the (nife and a ruler%

'- e too( the measurements of each potato cylinder ! using a ruler# and

recorded them% Then" we too( the cylinders to the balance and measured

each cylinderJs weigh and recorded them% ;- e too( ; petri dishes and lledeach one of them with a solution ! hypotonic" hypertonic" and isotonic#" and

we labeled them%


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C# distilled waterE# In ten percent 1a2l the red blood cell will shrin( and shrivel away

because water would leave the red blood and move out to the

!hypertonic# lower concentration of water area" however" in distilled

water" !hypotonic# the red blood cell will swell and eventually burst

because water molecules have a net movement into the cellF# water will move out of tube +" water will have no net movement in

tube b" and water will move into tube 2" this is because

!"periment #*. 3 )embrane +ermeability

)aterials:

K three test tubes

K test tube rac(

K boiling water bath at C. degrees celcius

K dialysis tube

K paralm

K starch solution

K glucose solution

K benedicts reagent

K iodine solution

K droppers

met-ods$

# rst we obtained a test tube and lled it half way up with water

'# then we obtained a strip of dialysis tubing and we tied a (not at one ofthe ends of the dialysis tube" then pulled on the (not a little bit to ma(e sure

that it was water tight"

;# we then opened the other end of the dialysis tube and" using the

dropper" we lled half of the dialysis tube with starch solution and the" using

a dierent dropper other half with glucose solution


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e"periment #*#7 plasmolysis in a green plant leaf

materials$

K live plant leaf

K compound light microscope

K '.0nacl solution

K the percentage of salt solution in the body cells is .%/0

)et-ods

# the microscope was prepared and all we had to do was observed

/esults and Discussion

+ost Lab 9uestions

/# water leaves the plant by process of osmosis" which is the movement of

water molecules from an area of high water concentration to an area of low

water concentration

'.#the '.0 salt solution is hypotonic to the solute concentration of the leaf

cells

'# put the leaf in a solution that has a lower !hypertonic# solute potential to

it and a higher water potential to it" so that the net movement of water

molecules is into the cell

''# in normal plant cells the chloroplasts can be found towards the edges of

the leaf" theyLre pushed there by the turgidity of the vacuole however" in a

salt treated plant leaf the chloroplasts would have been pulled away from the

edges of the cell near the plasma membrane

diffusion osmosis report.docx

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