Cell Structure and Function: Monomers, Tools, and Organelles

1. Cell Structure and Function

2. Do Now • What are the monomers of the following? • Carbohydrates • Proteins • Lipids • Nucleic Acids

3. Do Now • List some of the tools that scientists use to observe objects.

4. Cell-the smallest units of life in all living things

5. Hooke-discovery of cells was made observing dead plant cells. • Leeuwenhoek-first person to observe living cells • Schleiden-concluded that all plants were composed of cells. • Schwann-concluded that all animals were composed of cells. • Virchow-noted that all cells come from other cells.

6. All living organisms are composed of one or more cells. • Cells are the basic units of structure & function in an organism. • Cells come only from the reproduction of existing cells.

7. Each cell has a shape that has evolved to allow the cell to perform its function effectively. • A cell that can change its shape would be well suited for moving to different tissues through narrow openings.

8. The size to which a cell can grow is limited by its surface area. • Surface area is an important factor in limiting cell growth because the cell may become too large to take in enough food and to remove enough wastes.

9. Plasma Membrane-thin coverings that surround cells • Regulates what enters and leaves the cell • Also called “cell membrane” • Selectively permeable because it allows the passage of some solutes and not others. • “Fluid Mosaic Model” • Plasma Membrane

10. Plasma Membrane • Composed of a phospholipid bilayer. • Phospholipids line up tail to tail. • Outer region is hydrophilic. • Inner region is hydrophobic. • Proteins are inserted into the membrane to act as receptors to allow certain items in or out. • Cholesterol is inserted into the membrane to keep the plasma membrane fluid.

11. Do Now • What is the plasma membrane composed of?

12. Cytoplasm-includes the fluid (cytosol), cytoskeleton, & all of the organelles, except the nucleus. • Cytosol-the part of the cytoplasm that includes molecules & particles, but not membrane-bound organelles. • The fluid portion of the cytoplasm.

13. Nucleus-the membrane-bound structure that contains a cell’s DNA

14. Prokaryotes-lack a membrane-bound nucleus & membrane-bound organelles • Has no nucleus and no mitochondria, but it does have a plasma membrane, ribosomes, cytoplasm and a cell wall • Have no nuclear membrane • Existed on Earth before eukaryotes. • Nucleoid-the part of the cell that contains the DNA • Circular DNA • Ex. Bacteria & Archaea

15. Eukaryotes-made up of one or more cells; have a nucleus & membrane-bound organelles • Organelle-a structure within a cell that performs a specific function

16. Unicellular-one cell • Colony-collection of genetically identical cells that live together in a connected group. • Multicellular-cells become more specialized and eventually were unable to survive independently.

17. Tissue-a group of similar cells and their products that carry out a specific function. • Organ-groups of tissues that perform a particular job in an organism. • Organ System-group of organs that accomplish related tasks. • Organisms-several organ systems combine to make up an organism.

18. Immediately identifies a cell as an eukaryote. • Where the cell’s chromosomes are found • Nucleoplasm-jelly-like liquid that holds the contents of the nucleus

19. Nuclear Envelope-The double membrane surrounding the nucleus • Nuclear pores-protein-lined holes • Nucleolus-the more dense area where DNA is concentrated

20. Do Now • What is the nuclear membrane composed of?

21. Tiny organelles that transfer energy from organic molecules to ATP, which ultimately powers most of the cell’s chemical reactions. • An active cell might contain large numbers of mitochondria. • Where cell’s ATP is produced • Cristae-Folded, inner membrane of the mitochondria

22. Mitochondria have their own DNA & can reproduce only by the division of preexisting mitochondria. • Mitochondria originated from prokaryotic cells that were engulfed by ancient eukaryotic cells.

23. Do Now • Finish the sentence. • Nuclear DNA contains DNA from ___________, and mitochondrial DNA contains DNA from ________________.

24. Do not have a membrane. • Where proteins are made. • Assembly of the proteins begins in the nucleolus & is completed in the cytoplasm. • Some are free in the cytosol; others are attached to the rough ER. • Are found in both prokaryotic & eukaryotic cells.

25. An important organelle that helps maintain homeostasis by moving supplies from one part of the cell to the other • Rough ER-covered with ribosomes; assemble proteins. • Smooth ER-NOT covered with ribosomes; assemble lipids.

26. The packaging and distribution center of the cell. • Helps make & package materials to be transported out of the cell.

27. Vesicles-small, membrane-bound spherically shaped sacs that help transport materials in the cell • Vacuole-large vesicle • Amoeba Feeds • Lysosome-vesicles that bud from the Golgi apparatus & that contain digestive enzymes. • Food vacuoles-store nutrients for a cell. • Contractile vacuole-vesicles that can contract and dispose of excess water inside a cell. • Paramecium Feeds

28. Cytoskeleton-The mesh like network of protein fibers that supports the shape of the cell . • Microtubules- hollow tubes that hold organelles in place • Microfilaments- long threads that help the cell move • Intermediate Filaments- rods that maintain the internal shape of the nucleus.

29. Cilia-numerous hairlike organelles that protrude from the surface of a cell and are packed in tight rows • Flagella-longer & far less numerous on the cell. • Cilia & Flagella

30. Do Now • What is the mitochondrial membrane composed of?

33. Cell Wall-rigid layer that lies outside the cell’s plasma membrane. • Contain Cellulose • Has pores in the cell wall that allow water, ions, and some molecules to enter & exit the cell.

34. Central Vacuole-a large membrane-bound space in which water, waste products, and nutrients are stored

35. Plastids-organelles that are surrounded by a double membrane and contain their own DNA. • Chloroplasts-the organelles in plant cells that contain a green pigment and take part in photosynthesis • Contain DNA and chlorophyll • Chromoplasts-plastids that contain colorful pigments and that may or may not take part in photosynthesis.

36. Crash Course-Eukryotes

37. Cell Cookie Lab-DO NOT EAT • 1. Choose either a plant or animal cell • 2. Create 6 cell structures from the list below. • 3. Explain structure ANDfunction to Mrs. Kniha. • 4. Enjoy your cookie! • Cookie Structures: • Icing-Cytoplasm • Twizzlers-Plasma Membrane • Gel Icing-Cell Wall • Tic Tac-Chloroplast • Hot Tamale-Mitochondria • Sour Gummy Worms-Rough ER • Regular Gummy Worms-Smooth ER • Gummy Bears-Golgi Body • M&Ms-Nucleus • Marshmallow-Central Vacuole • Sprinkles-Ribosomes

38. Cell Cookie Lab-DO NOT EAT • All Cells • Icing-Cytoplasm • Twizzlers-Plasma Membrane • Hot Tamale-Mitochondria • Sour Gummy Worms-Rough ER • Regular Gummy Worms-Smooth ER • Gummy Bears-Golgi Body • M&Ms-Nucleus • Sprinkles-Ribosomes • Plant Cells Only • Gel Icing-Cell Wall • Tic Tac-Chloroplast • Marshmallow-Central Vacuole

39. Cell Cookie Lab-DO NOT EAT • All Cells • Icing-Cytoplasm-holds cells together • Twizzlers-Plasma Membrane-regulates what enters and leaves the cell • Hot Tamale-Mitochondria-produces ATP • Sour Gummy Worms-Rough ER-holds ribosomes • Regular Gummy Worms-Smooth ER-produces lipids • Gummy Bears-Golgi Body-repackages proteins • M&Ms-Nucleus-control center • Sprinkles-Ribosomes-produce proteins • Plant Cells Only • Gel Icing-Cell Wall-protects cell • Tic Tac-Chloroplast-does photosynthesis • Marshmallow-Central Vacuole-holds water