Cells

http://www.youtube.com/watch?v=gFuEo2ccTPA

What is a cell?•Smallest unit of a living thing.

• Cells make up Tissues which make up Organs which make up Organ Systems which make up Organisms!

• Organisms are Living things!

• Makes up organisms.

• Can be an organism (single-celled) creatures or …

•…multi-celled like us!

• Most cells are alive

• They reproduce, grow/develop, use/obtain energy, and adapt to their environment, contain chemicals.

Specialized cells• Have a

specific function that they serve…

http://www.youtube.com/watch?v=I8uXewS9dJU

Discovery of the Cell

http://www.youtube.com/watch?v=dscY_2QQbKU

Mathias Schleiden•Discovered that plants contain cells

Theodor Schwann

•Discovered that animals are made up of cells.

Rudolph Virchow

•Discovered that cells divide to create new cells.

All of these scientists contributed to the Cell

Theory…

•1) All living things are made up of one or more cells.

•2) Cells are the basic unit of structure and function of living things.

•3) All cells come from pre-existing cells.

• Prokaryotic Cells- “pro”- before karyon or kernel

• Cells without a nucleus

• Ex. Viral/Bacterial cell

• Eukaryotic Cells- “true karyon” or kernel

• Cells with a nucleus

• Ex. Plant, Animal cells

http://www.youtube.com/watch?v=yWy4o_UfZ4A

Of course none of this would have been possible without

Anton Van Leeuwenhoek and his early microscope!

We’ve come a long ways…

Organelle•Tiny “organs” that perform a specific job (function) inside of a cell.

•Structure- how it is made, what it is made of?

• Examples- Nucleus, Ribosomes, Mitochondria, ER

Cell WallOrganelles

Cell Wall- not found in ANIMAL cells pg. 173

Details, Diagrams, Explanations

Structure Fibers of carbohydrates/proteinsCellulose- carbo fiber

Function Support/Protection for cellAllows substances to pass into cell (H20, 02, CO2,)Selectively Permeable

RibosomesOrganelles

Ribosomes- pg. 177

Details, Diagrams, Explanations

Structure Round organelles Found in cytoplasm, rough ERSmall

Function Makes proteinsNucleus gives instructions

Cell Membrane•Controls what goes in/out of cell

•Protection•Support/Shape

Cell membrane___

1. Diffusion (passive)• “Molecules” moving from an area

of high concentration to an area of low concentration.

• Trying to reach a state of “equilibrium” where all molecules are evenly spaced!

Selectively Permeable• Allows or “selects” certain

materials to enter/leave the cell

• Good things- Vitamins, Minerals, Water, Oxygen

• Bad things- Viruses, Bacteria, Pirates

Passive Transport

Requires little to no cell energy to move molecules throughout the cell.1- Diffusion2- Osmosis

2. Osmosis (passive)

•The diffusion of WATER!

http://www.youtube.com/watch?v=IaZ8MtF3C6M

Osmotic pressure• Isotonic- balanced

• Hypertonic- cells shrink, vacuoles collapse

• Hypotonic- cells swell and burst!

Facilitated Diffusion

• Specific type of diffusion

• Passive

• Protein channels assist/allow passage through membrane

Active Transport• Movement through

a cell membrane (cell wall) in which the cell USES energy!

Endocytosis

• Type of active transport

• Brings materials into cell by capturing into “pockets”

Exocytosis

• Removal of materials from cell

• Pushes material out of the cell

• Active transport

Nucleus•Located in center of cell•Circular•Contains DNA/Genetic Info•The “Boss” of the cell.

Controls cell functions

Osmotic Pressure