Osmosis and Diffusion: Chyna and Marty

• Video link: https://www.youtube.com/watch?v=DvM6Bdkj1E0

• 

  Osmosis and Diffusion-0

• Example Data of Diffusion Agar Mini Lab:

Initial Color Final Color Acid (.1M NaOH) Colorless Colorless Base (0.1) Colorless Pink

Diffusion of various sizes of agar cubes placed in acid:

Diffusion of various sizes of Agar cubes placed in base:

When the cubes are dissected, the smallest cubes were found to have the largest surface area to volume ration. The smallest cube shown a complete change in color compared to larger size cubes.

• Example of Concept of Dialysis:

Solution Color

	Initial Components	Initial	Final
Bag	15% Glucose & 1% Starch	Clear	Violet
Beaker	H20 & IKI	Yellow-Orange	Yellow-Orange

Presence of Glucose

	Initial Components	Initial	Final
Bag	15% Glucose & 1% Starch	Yes	Yes
Beaker	H20 & IKI	No	Yes

• Equation of percent change in mass:

(Final Mass-Initial Mass)/ Initial Mass= Percent change in mass

ex. Initial Mass- 25

Final Mass- 35

(35-25)/35= .286= 28.6%

• Sample problems:

1. Solve for the percent change in mass when the initial mass is 36 and the final mass 60
2. Solve for the percent change in mass when the initial mass is 10 and the final mass is 10
3. Solve for the percent change in mass when the initial mass is 25 and the final mass is 28.

• Example Data of Potato Core Lab:

Contents in Beaker	Initial Mass	Final Mass	Mass Difference	Percent Change in Mass	Class Average Percent Change in Mass
a) 0.0 M Distilled Water	6.850 g	8.795 g	1.94	28.32%	22.8050
b) 0.2 M Sucrose	7.168 g	9.250 g	2.09	29.19%	14.5300
c) 0.4 M Sucrose	7.310 g	7.220 g	0.09	1.23%	2.6075
d) 0.6 M Sucrose	8.210 g	7.69	0.52	6.33%	9.3825
e) 0.8 M Sucrose	6.800 g	5.34 g	1.46	21.47%	21.0175
f) 1.0 M Sucrose	5.550 g	4.6	0.95	17.12%	21.4550

Graph

• Example Data of Dialysis Tubules Lab:

Table:

Contents in Beaker	Initial Mass	Final Mass	Mass Difference	Percent Change in Mass
Green	20.50g	23.19g	2.69	13.12%
Yellow	20.99g	24.55g	3.56	16.96%
Red	19.57g	20.7g	1.13	5.77%
Purple	20.26g	22.49g	2.23	11.00%
Blue	20.64g	22.21g	1.57	7.60%

Graph:

• Connections to other concepts in Biology

1. Active transport: This lab is related to active transport because active transport is a type of diffusion. Active transport is the movement of a substance across a cell membrane with an expenditure of energy against its concentration or electrochemical gradient. This type of diffusion requires a specific transport protein that will allow the substance to enter the cell. The difference between simple diffusion and active transport is that active transport requires ATP or another another energy source for the movement of the substance. A well known example of active transport is the sodium-potassium pump.
2. Structure of the Plasma membrane: This is related to the lab because the properties of the plasma membrane may or may not allow the movement of a substance across the cell membrane. The plasma membrane is described as a fluid mosaic model. The plasma membrane consist of a phospholipid bilayer with different proteins embedded in the fluid matrix of the bilayer. The phospholipids that make up the plasma membrane consist of a phosphate head and a lipid tail. The phosphate head is polar, and the lipid tail is nonpolar. The lipid tail inhibits polar substances such as water from entering the cell; therefore, water requires a transport protein that will facilitate diffusion.
3. Osmolarity: This lab is related osmolarity because organisms need to maintain water balance.Osmoregulation is the general process by which animals control solute concentrations and balance water gain and loss.Some organisms are osmoconformers. Osmoconformers are organisms animals that are isoosmotic with its environment. Osmoregulator are animals that controls its internal osmolarity independent of the external enviroment. The lack of water can cause dehydration of the animal. Also, organisms spend energy to maintain water balance or osmoregulate.

• Quizlet link:https://quizlet.com/80942218/chyna-flash-cards/
• Answers for Sample problems:

1. (60-36)/36= 67%
2. (10-10)/10= 0%
3. (28-25)/28= 1%