Science Fact of the Day:The human heart has enough pressure to squirt

blood up to 30 feet away.

Happy Thursday!Please write the questions and your answers on your Bellwork

page in your binder.

1. Name two major differences between prokaryotic and eukaryotic cells.

2. A scientist find an unicellular organism. He can see its DNA is free-floating in the center of the cell. What kind of cell is this?

3. Draw a picture to describe the Endosymbiotic Theory. (You do not need to write this question, just draw the picture)

CO: I will investigate cellular processes like homeostasis and

molecule transport.

LO: I will begin a lab and take notes on osmosis and diffusion.

Potato Lab Set-Up

• In your groups, each person needs to do one of the following jobs:– Person 1: Weigh the 3 potato pieces– Person 2: Label the 3 cups (A,B,C) and put the

beginning weight on each cups– Person 3: Fill the cups with the fluid– Person 4: Hold the cups for the “pourer”

A: Clear B: Red C: Blue

All cells are surrounded by a thin, flexible barrier known as a cell membrane.

What is the cell membrane’s function (job)?

(2 things)

The two main functions are: 1) to regulate what enters and leaves the

cell 2) to provide protection and support.

What is the cell membrane made (composed) of?

(3 types of molecules)

• The composition of cell membranes is a double-layered sheet called a lipid bilayer.

DRAW THIS!

Lipid

Phosphate

carbohydrate

Bi- means 2

Also called the phospholipid bilayer

Proteins are embedded in the lipid bilayer.

• Proteins form channels or pumps that help move large materials across the cell membrane.

• Carbohydrates are attached to many proteins embedded on the outside of the bilayer.

• The carbohydrates allow individual cells to identify one another.

How do substances move into/out of the cell membrane?

(4 ways)

Why does food coloring spread out in water?

• In a solution, particles are constantly moving.

• They collide with one another and spread out randomly.

Happy Friday!

Please have these two items on your desk:

• Video Notes homework • “Cell Size: Agar Lab” (lab with the chart

on the front and 5 questions on the back)– I am collecting it for a grade…so finish it

right now if you haven’t!

Bellwork:Pick a partner A and a partner B.

Partner A: Tell your partner what another name for the cell membrane is and what it means.

Partner B: Describe diffusion to your partner.

• Particles move from an area of high concentration to an area of low concentration.

• This is known as diffusion.

• The concentration is the amount of a substance dissolved into water.

(Kool-aid demo)

• A concentration gradient is a difference between two concentrations.

• Diffusion is the movement of particles down the concentration gradient.

High Concentration

Low Concentration

Crystal Light Commerical

• When the concentration of a solute is the same throughout a system, the system has reached equilibrium.

• When equilibrium is reached, particles do continue to move across the membrane.

• Substances that diffuse across a membrane do not require the cell to use energy.

• If a substance is able to diffuse across a membrane, it is permeable.

• If a substance cannot diffuse across a membrane, it is impermeable.

• Selectively permeable means that some substances can pass across while others cannot.

• Biological membranes are selectively permeable.

• Diffusion of water through a selectively permeable membrane is called osmosis.

• Remember: SALT SUCKS

Isotonic means “same strength”. Hypertonic means “above strength”. Hypotonic means “below strength”.

Draw This

Label: IsotonicWater: SameSolute: Same

Label: HypertonicWater: Low (outside cell)Solute: High

Label: HypotonicWater: High (outside cell)Solute: Low

The rest of class…

• Potato Lab: Complete the back of your lab paper. This is a grade!– Fill in the measurement on the cup in the column labeled “Day 1”– Fill in today’s measurement in the column labeled “Day 2”– Subtract to get the difference (“diff”)– Answer the questions.– Turn in to your class tray.

• If you finish that, work on Poker Chip activity.– Get a cell membrane picture, worksheet, and a bag of poker chips– Turn in to your class tray.