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