1. Cell Discovery History 1665 – Robert Hooke 1674 – Aton van Leeuwenhoek: observes tiny living organisms in pond water. 1838 – Matthias Schleiden: concludes that all plants are made up of cells. 1839 – Theodor Schwann: concludes that all animals are made up of cells. 1855 – Rudolph Virchow: all cells come from existing cells. – Cell theory 1970 – Lynn Margulis: said that certain organelles, tiny structures within some cells, were once free- living cells themselves.

2. What is the difference between prokaryotes and eukaryotes? Prokaryotes do not contain organelles. ex. bacteria Eukaryotes contain organelles. ex. Animal, plants, fungi, protists

3. Material in a Cell Chromatin – granular material in nucleus, consists of DNA bound to protein. Chromosomes – chromatin condensed. Seen when cell divides. Nuclear Envelope – two membranes surrounding the nucleus.

4. Nucleolus – small, dense region inside the nucleus. Where ribosomes are made. Chloroplasts and mitochondria have their own DNA.

5. Cytoskeleton – network of protein filaments that helps the cell to maintain its shape. – Microfilaments: threadlike structures made of a protein called actin. Help cells move. – Microtubules: hollow structures made up of proteins known as tubulins. Maintains cell shape. Important in cell division. Help build projections from the cell surface, which are known as cilia and flagella. Centrioles are made up of microtubules that aid in mitosis.

6. 7-3 Cell Boundaries Cell membrane: lipid bilayer -Contain protein molecules that are embedded in the lipid bilayer. Carbohydrates molecules are attached to many of these proteins. -“fluid mosaic model” -Proteins form channels and pumps that help move material across the cell membrane.

7. Cell walls Provide support and protection for the cell. Composed of cellulose.

8. Diffusion Particles tend to move from an area where they are more concentrated to an area where they are less concentrated. Equilibrium – when the concentration of the solute is the same throughout a solution. Diffusion occurs across a membrane without requiring energy.

9. http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ch apter2/animation__how_diffusion_works.htm l http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ch apter2/animation__how_diffusion_works.htm l

10. Osmosis Diffusion of water through a selectively permeable membrane.

11. Osmosis Water will move from an area of high concentration to an area of low concentration. Isotonic – same strength, concentration is the same on both side of the membrane. Hypertonic – above strength, more concentration solution. Hypotonic – dilute solution, low concentration. http://highered.mcgraw- hill.com/sites/0072495855/student_view0/chapt er2/animation__how_osmosis_works.html http://highered.mcgraw- hill.com/sites/0072495855/student_view0/chapt er2/animation__how_osmosis_works.html

15. Osmotic Pressure Cells might burst if it takes in too much water. Pg. 186

16. Facilitated Diffusion Protein channels that act as carriers, making it easy for certain molecules to cross. Different channels allow certain substances. Ex. glucose

17. http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ch apter2/animation__how_facilitated_diffusion _works.html http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ch apter2/animation__how_facilitated_diffusion _works.html

18. Endocytosis and Exocytosis Endocytosis – taking material into the cell by means of infoldings, or pockets, of the cell membrane. Form a vacuole within cell. Two examples: Phagocytosis – cell engulfs a particle. “cell eating” Pinocytosis – cell takes in small amounts of liquid and form a vacuole inside cell.

19. http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ch apter2/animation__phagocytosis.html http://highered.mcgraw- hill.com/sites/0072495855/student_view0/ch apter2/animation__phagocytosis.html

20. Exocytosis Releasing material from cell. Vacuole fuses to the membrane and releases contents outside of cell.

21. 7-4 The Diversity of Cellular Life Cells throughout an organism can develop in different ways to perform different tasks. – called cell specialization.

22. Specialized Animal Cells Ex. Red blood cells are specialized to transport oxygen – contains a protein that binds to oxygen in the lungs and transports the oxygen throughout the body where it is released. Prancreatic cells are packed with ribosomes and rough ER, which are where proteins are produced. Cells need a lot of enzymes that make it possible to digest food.

23. Levels of Organization Cells Tissues Organs Organ systems organism