DIALY

SIS

CE

L L TR

AN

SP

OR

T

INTR

ODUCTION

DIALYSISSmaller molecules are selectively separated

from larger molecules by diffusion through a semipermeable membrane

Semipermeable membrane - a membrane that allows the passage of selected ions or molecules

Occurs in the cell through the transporting of molecules and ions through the CELL MEMBRANE

This is a non mediated process meaning it does not need any aid of transport proteins

OBJECTIVES

1. To understand dialysis through the semi-permeability of longganisa skin

2. To observe which ion diffuses first out of the membrane.

MATERIA

LS A

ND

METHOD

CaCl

Methylene blue

Longganisa skin

H2O + Ca and Cl ions

Set-up

Ammonium Oxalate(react with Calcium)

Silver Nitrate(react with Chloride)

RESULTS A

ND

DISCUSSIO

NS

Time (min)

Chloride Test

Calcium Test

Methylene Blue

Methylene Blue

(Theoretical)1 - - - -2 - - - -3 - - - -4 - - - -5 - - - -6 - - - -7 + - - -8 + - - -9 + - - -10 + - - -11 + - - -12 + - - -13 + + - -14 + + + -15 + + + -

RESULTS OF DIALYSIS OF CALCIUM AND CHLORIDE IONS

REACTIONS FORMED:Cl- + Ag+ AgCl (precipitate)

Ca2+ + C2O42- CaC2O4 (precipitate)

Cloudy white precipitate formed in both test tubes. This indicates the presence of the Cl and Ca ions because they reacted with their respective reactants.

DISCUSSIONSChloride ions passed through the longganisa skin faster than calcium ions because they have a smaller molecular size/radius. On the other hand, methylene blue is large in size; much larger than the permeability of the longganisa can allow to pass through. Because of this, the molecules of methylene blue cannot pass through the longganisa skin.

DISCUSSIONSLongganisa skin is a differentially permeable membrane because it allows small-sized molecules to pass through (ie. Calcium and Chloride), and at the same time, prohibits the passage of large molecules (ie. Methylene blue).

CONCLUSIO

N

The longganisa skin allowed the passage of small molecules, chloride

and calcium ions, in which chloride ions passed through faster, and prohibited

the passage of the large molecules that is methylene blue thus exhibiting the

process dialysis.