Thursday Opening Question: What are at least five things that you know about cells? Agenda: Prokaryote/Eukaryote foldable Community Cells

Cells-R-Us Cell Theory- The cell theory consists of three components listed below: 1.) all organisms are made up of one or more cells, 2.) cells are the basic units of structure and function in all organisms, and 3.) all cells come from cells that already exist.

Eukaryotes and Prokaryotes Nucleus (plants and animals) No nucleus (bacteria)

ProkaryoteEukaryote Prokaryote versus Eukaryote

Plant CellsAnimal Cells Plant Versus Animal

Cell Membrane Nickname: “the fence” Function: boundary separating the cell from surrounding cells and invaders Controls what enters and exits the cell

Cytoplasm Nickname: “the air” Function: jelly-like material inside the cell membrane. Surrounds the nucleus and organelles.

Ribosomes Function: makes proteins Found in all cells, prokaryotic and eukaryotic

Endoplasmic Reticulum (ER) Nickname: “Roads” Function: The internal delivery system of the cell

Golgi Apparatus Nickname: The shippers Function: packages, modifies, and transports materials to different location inside/outside of the cell Appearance: stack of pancakes

Lysosomes Lysosomes: circular, but bigger than ribosomes) Nickname: “Clean-up Crews” Function: to break down food into particles the rest of the cell can use and to destroy old cells

Mitochondria Nickname: “The Powerhouse” Function: Energy formation Breaks down food to make energy

Vacuoles Nickname: The warehouse Function: stores water This is what makes lettuce crisp When there is no water, the plant wilts

In Plants Only: Cell Wall Located on the outside of the cell membrane. Acts as an extra fence. Supports and protects the plant cell. Chloroplasts Organelles that capture energy from sunlight. Aids in photosynthesis.

Exit Slip things you learned 2 ways you contributed 1 question you still have On flip side, tell me: the difference between a prokaryote and a eukaryote

Agenda Review Cells project Project presentation Exit slip

Nucleus Nickname: The Brain Function: Contains the DNA and controls all functions within the cell.

CELLS!!!! Construct a model of an plant cell by adding one organelle (cell part) at a time using construction paper. Create an organelle from the sheet given, color and add it to your drawing. I will pass out to each group an organelle sheet. Clearly label & Recreate that organelle and cut it out and put it in your cell. Be prepared to present an organelle to the class.

CELLS!!!! The last organelle you receive will be the one you present. One person from each group must present. The best Cell project picked and the best presenter will each get a 5 point bonus towards their cell book project.

Exit Slip 1 question you still have Below that: Two differences between a Ribosome and a Mitochondria

Wednesday Opening Question: What do you know about a microscope? Agenda: Lab Review Quiz

Thursday Opening Question: What do you know about Osmosis? Agenda: Plant and animal cell foldable Review Osmosis

Review Organelles Name Nickname Function

Plant CellsAnimal Cells Foldable

Diffusion Diffusion- the movement of molecules from an area where there are many to an area where there are few Movement of molecules from an area of high concentration to an area of low concentration.

Functions of Membranes 1. Protect cell 2. Control incoming and outgoing substances 3. Selectively permeable - allows some molecules in, others are kept out

Phospholipid Bilayer

Blood-Brain Barrier Allows some substances into the brain, but screens out toxins and bacteria Substances allowed to cross include: water, CO 2, Glucose, O 2, Amino Acids, Alcohol, and antihistamines. HIV and bacterial meningitis can cross the barrier.

Methods of Transport Across Membranes 1. Diffusion -passive transport - no energy expended 2. Osmosis - Passive transport of water across membrane 3. Facilitated Diffusion - Use of proteins to carry polar molecules or ions across 4. Active Transport - requires energy to transportmolecules against a concentration gradient – energy is in the form of ATP

Diffusion

Osmosis

Facilitated Diffusion

Active Transport

Osmosis Osmosis- the diffusion of water through a cell membrane

1

Osmosis is a special case of diffusion Osmosis involves the diffusion of water through a membrane The membrane may be artificial and non-living e.g. Cellophane In biology, the important membrane is the cell membrane 2

If a concentrated solution is separated from a dilute solution by a suitable membrane, water will pass from the dilute to the concentrated solution. The membrane must allow water molecules to diffuse through. It is permeable to water. In fact, water passes both ways but faster from the dilute to the concentrated solution. Permeability 3

Osmos is water or dilute solution concentrated solution membrane More water passes from dilute to concentrated......until concentrations become equal level riseslevel falls 4

There are microscopic pores in the membrane. Molecules below a certain size can diffuse through the pores. Water molecules can easily diffuse through the pores. In the next slides represents a water molecule and represents a sugar molecule 5

membrane watersugar solution There are as many water molecules on the right as there are on the left but many of them are attached to sugar molecules and are not free to move. 6

Because the membrane allows only molecules of a certain size to diffuse through it, it is called selectively permeable. The cell membrane functions as a selectively permeable membrane. 9

There is a greater concentration of free water molecules outside the cell than inside so water diffuses into the cell by osmosis and the cell swells up Osmosis in animal cells 11

If osmosis continued the animal cell would burst This would be bad news for animals Consequently there are processes in the animal’s body which control osmosis Mainly, this is done by keeping the concentration of body fluids outside the cell the same as it is inside. This is called homeostasis. 12

In fresh water fish, the blood is more concentrated than the surrounding water As a result the fish takes in water by osmosis Not so much through the skin, which is thick, but through the gills which have a very thin membrane Trout Fresh water fish 14

The fish gets rid of the excess water by means of its kidneys Perch gills absorb water by osmosis blood carries water to kidneys kidneys expel excess water......in the form of dilute urine heart 14

Sea water is a more concentrated solution than the fish’s blood. What will be the osmotic effect ? A sea water fish will lose water by osmosis through its gills. The fish drinks sea water and the gills expel the excess salt from the blood, so keeping its concentration constant Herring Sea water fish 15

In a plant cell, the cell membrane acts as a selectively permeable membrane If there is water outside the cell, it will diffuse by osmosis into the vacuole The cell wall is freely permeable to water 16

The cellulose cell wall cannot stretch, so the vacuole cannot continue to expand But the pressure of the vacuole against the cell wall makes the cell very firm and the plant stands upright 17

cell wallcytoplasm and cell membrane vacuole The cell absorbs water by osmosis but the cell wall stops the cell expanding any more Plant cells 18

These cells are short of water; the tissue is limp and the plant is wilting The cells have taken up water by osmosis; the cells are turgid and the tissue is firm Limp and turgid tissue 21

Exit Slip 1. Materials are moved into and out of the cell through which organelle? a. cell membrane b. mitochondria c. ribosomes d. nucleus 2. What process allows water to move into and out of the cell? a. Diffusion b. Meiosis c. Osmosis d. Pinocytosis

56 Wednesday, March 3, 2010 Opening Question: Mitosis is the process in which the nucleus divides to form two new nuclei. How might mitosis differ in plants and animals? Also, please put the “mitosis” definition in your binder glossary. Agenda: Mitosis Notes

How do little elephants grow up to be BIG elephants?

The process of sexual reproduction begins after a sperm fertilizes an egg.

Skin cancer - the abnormal growth of skin cells - most often develops on skin exposed to the sun. Cell that reproduce by asexual reproduction reproduce constantly.

Animated Mitosis Cycle Interphase Prophase Metaphase Anaphase Telophase & Cytokinesis

Chromosomes are copied (# doubles) Chromosomes appear as threadlike coils (chromatin) at the start, but each chromosome and its copy(sister chromosome) change to sister chromatids at end of this phase CELL MEMBRANE Nucleus Cytoplasm

Animal Cell Plant Cell Photographs from:

Mitosis begins (cell begins to divide) Centrioles (or poles) appear and begin to move to opposite end of the cell. Spindle fibers form between the poles. Centrioles Sister chromatids Spindle fibers

Animal Cell Plant Cell Photographs from: Spindle fibers Centrioles

Chromatids (or pairs of chromosomes) attach to the spindle fibers. Centrioles Spindle fibers

Animal Cell Plant Cell Photographs from:

Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell. Centrioles Spindle fibers

Animal Cell Plant Cell Photographs from:

Two new nuclei form. Chromosomes appear as chromatin (threads rather than rods). Mitosis ends. Nuclei Chromatin

Animal Cell Plant Cell Photographs from:

Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes.

Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

Plant Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

I Interphase P Prophase M Metaphase A Anaphase T Telophase C Cytokinesis IPMATC I Pray M ore At T he Church

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77 - Cell Division 77