Cells, cells, and more cells!

AGENDA:
1) Quiz

2) Bring up 34-35 with stampsheet

3) Discuss diffusion lab and osmosis in cells

4) Discuss pH, enzymes and tomorrow's lab

5) Plasmolyzed lab on UP 36-37

HOMEWORK:

1) Finish Normal And Plasmolyzed Cells on UP 36 and 37

2) Enzymes pre-lab

For enzymes pre-lab, use UP 24-27 and section 2.4 to help answer the questions.

First off, we completed the quiz and got our stamps for homework completion. Afterward, we discussed the diffusion lab and osmosis in cells.

In the diffusion lab, we came to the conclusion that the iodine diffused into the membrane and the glucose diffused out of the membrane. We also came to the conclusion that the starch did not diffuse because the molecules were too big to pass through the membrane.

For osmosis, Mrs. Stein explained a situation in where the cell had 1% salt and 99% water and was put in an environment where there was 100% water. The surrounding water would perform osmosis and enter the cell. Since there is 100% water, it's more than the cell can handle, the cell explodes. This is also known as cytolysis.

We also discussed another situation about adding salt water to a fresh water plant, which was also what we did for our lab in class today. The cell origianally has 99% of water and the environment has 94% of water. The cell has more water than it's environment. Osmosis occurs and the 94% of water diffuses into the cell, which is less than the original amount of water it had. Since it doesn't have as much water, the cell becomes dehydrated. This causes the cell membrane to pull away from the cell wall. This is called plasmolysis.

For the lab, we had to make two wet mounts which both consisted of a leaf from the Elodea plant. We were to observe and record the results. Look below for pictures from the results of the lab.

This is the Elodea leaf with salt water. Sorry the picture is a bit small but the yellow outlined is the cell wall and the red outlined is the cell membrane. The cell wall is in it's normal shape but the cell memrane began to pull away.

CLOSE UP VERSION OF ELODEA LEAF IN THE PROCESS OF PLASMOLYSIS.

This is what the Elodea leaf originally looks like with fresh water.

Next Scribe- Josh Kim.