Video Previews Diffusion and Osmosis Lab
.pdf
School
Western High School**We aren't endorsed by this school
Course
WESTERN HIGH SCHOOL 101
Subject
Biology
Date
Jan 14, 2025
Pages
2
Uploaded by PrivateField560
AP Biology Lab 1 Bozeman Science- Diffusion and Osmosis Important Learn List: 1. Diffusion is achieved with the movement of a higher concentration on one side of a membrane to the lower concentration on the other side, to reach an isotonic solution. This means equilibrium will be reached. 2. During osmosis diffusion, a semipermeable membrane blocks the movement of solute particles like sugar, for example, who cannot pass through. In direct contrast, it only allows water to pass through. 3. During osmosis with a semi-permeable membrane, one side of the container will rise in height because water will flow from an area of high concentration to low concentration. This is because equilibrium will not be reached with the water solvent. Interesting List: 1. I would like to learn more about applications of diffusion. For example, the video explains an example with a jar that is divided in the center by a membrane. That membrane allows materials to move back and forth. They start at 0 minutes and come back at 15, showing how the sugar molecules move from the larger concentration side to the lower concentration side. The sugar concentration will be constant on each side (isotonic), with the water still flowing between each side. This is an example of how diffusion takes shape in our world. Other examples like red blood cell diffusion and container interaction diffusion are other examples I would like to learn more about. 2. When osmosis is occurring, one side will be hypertonic meaning it has more solute on that side and less water. The other side will be hypotonic meaning it has more water than solute concentration. I would like to learn more about these hypertonic and hypotonic interactions including the rate of these occurring, how fast, in different examples, etc. Questions: 1. What factors affect the rate of diffusion and to what extent? Synopsis - Part 1 of Lab (Diffusion)
Before:• First we will use dialysis tubing, with tiny holes surrounding the container. • Then we will have a beaker where we will put Water and IKI (Iodine)• Inside the dialysis tubing, we will have water, glucose, and starch. We can examine if glucose is present using testape. • Then we will let it rest in a controlled environment for approximately 40 minutes. • If IKI and starch are present together, the dialysis tubing will change blue. After: • After 40 minutes, the dialysis tube becomes a blue color. • When we examine the tubing after the waiting period is completed, we can see that starch and water are still there. We can infer IKI has moved inside because IKI and starch make a blue color. • This is because whenever starch and IKI are in the same area, there will be a blue color. • When we observe the rest of the beaker, we can see that glucose, IKI, and water are present. • However, we know there is no starch because there’s no blue color. • Based on these observations and changes, we can conclude that the holes are larger than the IKI because the IKI was able to move outside the dialysis tubing. • These pores are not bigger than the starch because starch was not able to exit the tubing.Synopsis - Part 2 of Lab (Osmosis) • Cut out the core of a potato. • Insert the core into beakers with various concentrations of sugar. In this case, we will put them into 0 Molar, 0.2 Molar, 0.4 Molar, 0.6 Molar, 0.8 Molar, and 1.0 Molar. • We will measure the mass of these beakers on day 1 and then record the mass of them on day 2. • When we have the core potato in 0 and 0.2 Molar, the cores are rising in mass from day 1 to day 2 because of osmosis. In short terms, the water is moving from the high concentration within the beaker to a lower concentration within the inside of the potato. • For the 0.4, 0.6, 0.8, and 1.0 molar samples, the potato is decreasing in mass from day 1 to 2. This is because when the potato core is sitting in great molarity water such as sugar, the water is moving from inside the potato core outward into the surrounding water.