Understanding Cells: The Basic Unit of Life

1. Chapter 7: Cells

2. What is a cell? Cell – Basic unit of structure and function in all living things

3. Cell Study and Discovery • . • Matthias Schleiden (1888) – All plants are made up of cells • Theodore Schwann (1889) – All animals are made up of cells • Rudolph Virchow (1889) – Cells come from pre- existing cells.

4. The Cell Theory • All living things are made up of cells • Cells are the basic unit of structure and function in all living things • Cells come from pre-existing cells

5. Shape – Form reflects function. Red Blood Cells are like tubes at Sesame Place so they flow easier Nerve cells are like electrical wires Cheek cells (Epithelial cells) are flat to act like a shield White Blood cells are amoeboid shaped to move and squeeze into all areas

6. Types of cells • Prokaryotic cells • Primitive cells – “before the nucleus” • No membrane boundorganelles • No nucleus • Found in Eubacteria and Archaeabacteria • Cell wall, cell membrane, cytoplasm, DNA & ribosomes

7. Eukaryotic “True nucleus” • Have membrane – bound organelles • All other kingdoms but Archaeabacteria & Eubacteria • Organelles such as: Mitochondria, endoplasmic reticulum, vacuoles, lysosomes, and chloroplasts.

8. Comparing the Two Cytoplasm DNA Cell Membrane

9. Structures common to both Prokaryotic and Eukaryotic cells • Cell Membrane • Ribosomes • DNA • Cytoplasm • Cell Walls(not in Animal or some Protist cells though!) Organelle – small structures in cells that have a specific function

10. Cell Organelles and Their Functions • Cell Membrane – Outermost boundary in all Animal Cells. • Separates the cell’s internal environment from the external environment. • Allows for the passage of some substances based on size and concentration • Selectively Permeabledue to pores being present

11. Made up of a bilipid layer (lipid bilayer) – 2 layers of lipids with proteins floating through it.

12. In the "fluid mosaic model" of membrane structure, the membrane is a fluid bilipid layer in which protein molecules are either partially or wholly embedded. These layers easily movearound Lipids Protein Rap

13. Nuclear Membrane 2. Nucleus • Only in Eukaryotic cells. • *Stores hereditary information. • Surrounded by a double nuclear membrane or envelope w/ pores • Chromatin(strands of a combination of DNA and protein within nucleus. These will later become Chromosomes. • Nucleolus(1 or >) produces ribosomes Chromatin Nucleolus

14. Cytoplasm – “cell’s liquid” - Made of a gelatinous fluid (Cytosol) between the nucleus and cell membrane Cyclosis– streaming movement of the cytoplasm. *Suspends organelles in place and carries material in solution around cell

15. 4. Cytoskeleton • Network of protein strands that provide support and mobility of organelles in cytoplasm. • 2 components of cytoskeleton - Microfilaments and Microtubules (both made of protein)

16. 5. Mitochondria - *Powerhouse of the cells. - Changes chemical bond energy of glucose into a usable form - *Site of Cellular respiration - Contains Cristae or folds to increase surface area - Has its own DNA and ribosomes and can replicate! - Found in greater numbers in cells such as muscle cells & liver cells (2500/cell) Cristae Double Membrane

17. Ribosomes – Most numerous organelle. *Site of protein synthesis. Made up of RNA and protein. May be free floating in cytoplasm or attached on Endoplasmic Reticulum

18. Endoplasmic Reticulum – Channels or passageways in the cell. • There are two types of ER: 1 – Rough w/ ribosomes attached for production & distribution of proteins. 2 – Smooth – Synthesis of lipids& detoxification of toxins

19. 8. Golgi Apparatus (Bodies) – Stack of smooth flat sacs - Modifies, collects, packages & distributes molecules to all parts of a cell

20. Lysosomes - *Produces digestive enzymes • Are the cells' garbage disposal system. They breakdown worn out organelles • Clean up dead cells • Responsible for the un-webbing of hands of fetus while developing in utero • These are rare in plant cells

21. 10. Vacuoles - *Stores food, water and wastes - Plant cells have a very large central water vacuole for support (turgor) - Animal cells have many small vacuoles

22. 11. Centrioles – Found in animal cells 2 perpendicular bundles of microtubules - Function during cell division

23. Plant Cells’ Unique structures Plastids –Store starch or fats and many contain pigments to absorb light. - Chloroplasts - Double membraned. Contain Chlorophyll and DNA Convert solar energy into chemical bond energy of glucose (Photosynthesis)

24. Amyloplasts (Leucoplasts)Store starch

25. Cell Wall – Gives cell rigidity, support and protection. - Made up of cellulose with pectin (glue) between adjacent cells.

26. Nucleus • Ribosomes • Mitochondria • Chloroplasts • Cell Membrane • Cytoplasm • Cell Wall • Central Vacuole • Golgi Apparatus • Endoplasmic Reticulum Typical Plant Cell

27. Cheek Cells Nucleus Cytoplasm Cell Membrane

28. Elodea Cyclosis

29. Onion Cells

30. Amyloplast Cell Wall Potato Cells

31. 1. _______________ 2. _______________ 3. _______________ (Dots) 4. _______________ 5. _______________ 6. _______________ 7. _______________ 8. _______________ 9. _______________ 10._______________ 11._______________ 12._______________ 13._______________

32. Typical Animal Cell • Nucleolus • Nucleus • Ribosome • Vacuole • Rough ER • Golgi Apparatus • Microtubule • Smooth ER • Mitochondria 10. Vacuole 11. Cytoplasm 12. Lysosome 13. Centriole Typical Animal Cell