Iodine and Starch lab1. Show iodine with starch solution, sugar solution and

distilled water2. Show dialysis tubing – it is semi-permeable3. Put starch solution in tubing, tie up and place in beaker of

water.4. Put iodine into water – pictures would be helpful – Lab 15. While we wait – go through the lab write-up sheet. We

have done the section on data collection using tables. We will be looking at graphs to analysis our data.

6. Then go through problem, hypothesis and variables. If time write up the procedure we did

7. Check tubing, record data somehow8. Discuss/analysis results9. Now, what would happen if we put the starch in the

beaker and the iodine in the tubing – lab 2

Requirements1. Describe the results for lab 1. At least

one picture is required.2. Explain the results in paragraph form.

This will help you figure out your hypothesis for lab 2.

3. State your hypothesis for the second procedure and give your reason why

4. List your independent and dependent variables and 3 good variables to control

5. Briefly describe the procedure you would do for lab 2. It can be in numbered form or paragraph but it must be reproducible. It should include a picture of the set-up

6. Explain why Step one was necessary

Cell Membrane

Controls what enters and leaves the cell

But HOW??

Its all in what it is made of and how it organizes the molecules

So, we know that the membrane is specially

designed to help substances pass in and out.

But how do things actually pass in and out???

Using inspiration

http://www.wiley.com/legacy/college/boyer/0470003790/animations/membrane_transport/membrane_transport.htm

Good site for diffusion, osmosis etchttp://www.biologycorner.com/bio1/notes_diffusion.html

Watch the cell membrane pull away from the cell wall

Plant cells in a hypertonic solution

Plant cells in a hypOtonic solution

Doesn’t require energy Requires energy

Watch one celled organisms ooze in preparation for endocytosis

Paramecium using a vacuole to expel substances

Take a lot of salt into your body and your metabolism very quickly goes into crisis. From every cell, water molecules rush off like so many volunteer firemen to try to dilute and carry off the sudden intake of salt. This leaves the cells dangerously short of the water they need to carry out their normal functions. They become, in a word, dehydrated. In extreme situations, dehydration will lead to seizures, unconsciousness and brain damage. Meanwhile, the overworked blood cells carry the salt to the kidneys, which eventually become overwhelmed and shut down. Without functioning kidneys you die. That is why we don’t drink sea water

We also know from doing a lab, that surface area

matters. You have to touch a cell membrane (surface)

before you can actually get into or out of a cell.

So if you get too large for your surface area, you have

trouble moving substances in and out.

You must divide instead!

Life cycle of a typical cell

PHASES OF MITOSIS

*IPMAT1. PROPHASE2. METAPHASE3. ANAPHASE4. TELOPHASE

PROPHASE

• 1st phase of mitosis• Chromosomes condense• Sister chromotids visible• Centrioles migrate to poles (animal

cells)• Spindle fibers form and attach to

centromeres• Nuclear membrane and nucleolus

disappear

METAPHASE

• META =MIDDLE• Chromosomes are pulled to the

middle• Chromosomes line up on the

Metaphase or Equatorial plate

ANAPHASE• Centromeres divide• Spindle fibers pull sets of CHROMATIDS

towards opposite poles• CHROMATIDS separate to form 2 identical

sets of daughter CHROMOSOMES• Ends when 2 sets are at opposite ends of

the cell

TELOPHASE• Last phase of Mitosis (Reverse of Prophase)

• Nuclear envelope (membrane) forms around each set of chromosomes.• Chromosomes uncoil Chromatin• Mitotic spindle fibers disassemble.• Membrane pinches in.

CYTOKINESIS• DIVISION OF THE CYTOPLASM– Animal Cells - Cell membrane pinches in until it

meets and forms 2 cells– Plant Cells - Cell plate forms a double membrane,

a new cell wall forms between them.WHY IS CYTOKINESIS DIFFERENT IN PLANTS

AND ANIMALS?

Go to this site, click on onion cell activity in the left hand column. Read and go through until you get to the activity.

http://www.biology.arizona.edu/

http://biologyinmotion.com/cell_division/

Interactive on mitosis