Dialysis Tubing
Nicholas MacLean and Erin Girhiny
Wednesday, October 19th, 2016
Mrs. Booth
SBI 4U
Purpose
The movement of different molecules through dialysis tubing was observed.
Materials
Starch
Glucose
Water
Dialysis Tubing
Iodine
String
Scapula
Scale
Benedict 's Solution
Test Tubes
Test Tube Rack
Hot Plate
Procedure
Lab was demonstrated by teacher.
Observations
Observation of Physical Properties After Time and Heat
Initial Observations
Observations After 24 hours
Observations After heating with Benedict’s Solution
ICF (glucose,starch,H2O)
Cloudy
White
26.38g
Dark Blue/Black
Opaque
27.02g
Bright Orange
Murky
Opaque
ECF (H2O + I2)
Transparent
Goldish
Transparent
Liquid
Clear
Orange/Red
Murky
Opaque …show more content…
Iodine can be found in the oceans, in the air and the soil, and can be ingested through bread, sea fish and oceanic plants.(1). Iodine can not be made by the body, so it is necessary for it to be ingested. The thyroid gland needs iodine to make hormones, if not enough Iodine is ingested, feedback systems in the body cause the thyroid to work harder. This can cause an enlarged thyroid gland (goiter). Other consequences of not having enough iodine are low levels of thyroid hormone can cause women to stop ovulating, leading to infertility. If the deficiency is prolonged it could lead to thyroid cancer.(2). Another application of Iodine is water purification. Iodine purifies water by oxidizing the bacteria in the water causing the iodide atoms to be reduced to negative iodine ions which disrupts the ion balance and the bacteria is killed.(3). Iodine is also used to test for the presence of starch: Lugol’s iodine solution (H2O + I2) is how this is tested. The presence of starch is indicated by a colour change causing the starch to turn black.(4). The component of starch which causes the colour change is amylose. The iodine molecule slides inside the amylose coil. However, iodine is insoluble in water so it is added to potassium, creating the the iodine reagent which dissolves in amylose causing the cloudy white colour to become black.(5). The Iodine in the ECF was able …show more content…
In this lab the dialysis was used for the diffusion and osmosis of iodine, glucose, starch and water. However, starch was unable to pass through the membrane due to it being too large. This is where it does not fully resemble a cell membrane because it can not transform and undergo things such as endocytosis to allow all the molecules to pass through.
Conclusion This lab provided a good perspective of the movement of molecules diffusing and going through osmosis into a cell. The ability of the cell membrane to be selective was illustrated by it not allowing all the molecules through (starch). This shows how in a real cell it can differ between essential and nonessential or invading molecules. Lastly, It gave a good example of hypertonic solutions and how the concentration gradient
Nicholas MacLean and Erin Girhiny
Wednesday, October 19th, 2016
Mrs. Booth
SBI 4U
Purpose
The movement of different molecules through dialysis tubing was observed.
Materials
Starch
Glucose
Water
Dialysis Tubing
Iodine
String
Scapula
Scale
Benedict 's Solution
Test Tubes
Test Tube Rack
Hot Plate
Procedure
Lab was demonstrated by teacher.
Observations
Observation of Physical Properties After Time and Heat
Initial Observations
Observations After 24 hours
Observations After heating with Benedict’s Solution
ICF (glucose,starch,H2O)
Cloudy
White
26.38g
Dark Blue/Black
Opaque
27.02g
Bright Orange
Murky
Opaque
ECF (H2O + I2)
Transparent
Goldish
Transparent
Liquid
Clear
Orange/Red
Murky
Opaque …show more content…
Iodine can be found in the oceans, in the air and the soil, and can be ingested through bread, sea fish and oceanic plants.(1). Iodine can not be made by the body, so it is necessary for it to be ingested. The thyroid gland needs iodine to make hormones, if not enough Iodine is ingested, feedback systems in the body cause the thyroid to work harder. This can cause an enlarged thyroid gland (goiter). Other consequences of not having enough iodine are low levels of thyroid hormone can cause women to stop ovulating, leading to infertility. If the deficiency is prolonged it could lead to thyroid cancer.(2). Another application of Iodine is water purification. Iodine purifies water by oxidizing the bacteria in the water causing the iodide atoms to be reduced to negative iodine ions which disrupts the ion balance and the bacteria is killed.(3). Iodine is also used to test for the presence of starch: Lugol’s iodine solution (H2O + I2) is how this is tested. The presence of starch is indicated by a colour change causing the starch to turn black.(4). The component of starch which causes the colour change is amylose. The iodine molecule slides inside the amylose coil. However, iodine is insoluble in water so it is added to potassium, creating the the iodine reagent which dissolves in amylose causing the cloudy white colour to become black.(5). The Iodine in the ECF was able …show more content…
In this lab the dialysis was used for the diffusion and osmosis of iodine, glucose, starch and water. However, starch was unable to pass through the membrane due to it being too large. This is where it does not fully resemble a cell membrane because it can not transform and undergo things such as endocytosis to allow all the molecules to pass through.
Conclusion This lab provided a good perspective of the movement of molecules diffusing and going through osmosis into a cell. The ability of the cell membrane to be selective was illustrated by it not allowing all the molecules through (starch). This shows how in a real cell it can differ between essential and nonessential or invading molecules. Lastly, It gave a good example of hypertonic solutions and how the concentration gradient