The Cell is the Basic Unit of Living Things!

1. The cell is the natural granule of life in the same way as the atom is the natural granule of simple, elemental matter. If we are to take the measure of the transit to life and determine its precise nature, we must try to understand the cell. Pierre Teilhard de Chardin (1955) The Cell is the Basic Unit of Living Things! All Organisms are Cells or composed of Cells! Cells are the smallest units capable of carrying out all Characteristics of Living Things!

2. Basic Cell Types. ProkaryoticCells – (pro; before / karyo; nut or seed.) The Simplest First Cells a. Very Simple Cells with No membrane bound Organelles*. b. Mostly one-celled organisms = Bacteria. So, typically drawn with no complex internal stuff!

3. Bacterial Cells are apparently very simple compared to Eukaryotes, so why have they survived and thrived on Earth? Reproduce FASTER! Evolve FASTER! Can fill many niches. Can “shut-down” to “Hibernate” and survive!

4. Basic Cell Types. EukaryoticCells – (Eu; true / karyo; nut or seed.) • Advanced Large Cells. • Have “membrane bound organelles*.” Most familiar organisms. Ex. Plants/Animals/Fungi. • Organelle = “Little” “Organ” Compared to Bacteria!

5. Organelles - Cellular components that perform specific functions within the cell. When one organelle takes care of one function, the other organelles can then become specialized themselves!

6. Eukaryotes have many specialized compartments that each perform specific tasks. These are the Organelles! Organelles are like factories – they are dedicated to specific tasks and can then perform at a higher level. Cells can be larger, more specialized (leading to multicellular!), and more capable! Eukaryotic Cells are individually better! TEAMWORK!!

7. The Plasma Membrane: Surrounds/Seals off the Cell. Also known as the Cell Membrane. Forms a Barrier within Water by using Phospholipids. Controls Access to and Maintains Homeostasis within the Cell. Lipids are the Barrier! Proteins are the Controlling “Doors”. Plasma Membrane Controls Access! Selective Permeability! Cell Border!

8. The Cell Wall: Not really an “Organelle” Found Outside Cells of almost all Cells EXCEPT Animals!.

9. Rigid Structure outside the Plasma Membrane. Extracellular Materials Produced and Released by the Cell! Supports/Protect - Usually a Rigid Structure! Often a Carbohydrate - Like Cellulose! Cell Wall Outside Cell! Protection! Cellulose in Plants! Why Cellulose?!

10. Cytoplasm = the liquid matrix of the Cell between the plasma membrane and the Nucleus. Contains the Aqueous Solution filling the cell (Cytosol) and the various Organelles. Living Liquid Cell Cytoplasm Aqueous = Water based! Site for Chemistry! Gel!

11. Nucleus (Control Center of the cell) Membrane Bound - enclosed in a double-membrane that protects/surrounds the DNA. Nuclear Pores - provide controlled access. Near the center of the cell due to its importance in producing RNA that carries out its Genetic “Orders”!

12. Nucleus (the Genetic Library) Contains DNA - The genetic Information must be protected in a controlled area! Chromatin - Loose, Active DNA. When it coils up and is inactive = Chromosomes. Nucleolus(i) - Dense area where the ribosomes (one form of RNA) are manufactured. Chromatin Includes/IS DNA! Genetic Info! Protected Material! Nucleolus Dark Spot inside Nucleus! Ribosome made in the Nucleus! Then they Leave.

13. Ribosomes Cellular Site for Protein Production. Free or Associated with the Rough ER. Made of RNA and Produced in the Nucleus (Nucleolus). “Spots” are the ribosomes. Ribosome Make Proteins! Work in the Cytoplasm! Free or Associated with ER. “Dotted Ribbons” are the proteins being made. What are the visible “dots”?

14. Endoplasmic Reticulum (ER) (folded internal membranes in the cytoplasm, site of manufacture of many substances) Rough ER (rough = ribosomes) - site of protein synthesis for export from the cell (secretion). Smooth ER (no ribosomes) - site of lipid production, including steroids and phospholipids. ER Rough ER makes Proteins to be Packaged! Smooth ER makes Lipids (etc..) to be Packaged!

15. .Golgi Apparatus (membrane sacs associated with the ER) Sorts, Purifies, and Packages many organic molecules originally made in the ER. Responsible for Producing Plasma Membranes. Resembles a “Stack of Pancakes”. Golgi Apparatus Post Office! Collects and Organizes all of the Molecules manufactured in the ER!

16. The Golgi Apparatus produces purified packages of various materials. These Materials are transported throughout the cell in TransportVesicles. Plasma Membrane - Bilayer and membrane proteins are organized in the Golgi. Lysosome - contains digestive enzymes to breakdown food, destroy other cells, clear out old organelles, or commit cell suicide. One of Them! Lysosome Digestive Organelle! Carries purified Proteins used to break things down. Vesicles Transport Pod! Moved throughout the Cell to carry substances to their appropriate Site.

17. 4. Specialized Vesicles carry the Final Products!! 3. Golgi sorts them out! Digestion!! Release!! Nucleus carries the Genetic Info! Esp. note the: Plasma Membrane!! 2. Transport Vesicles carry the molecules. All Sorts of Different Materials! 1. ER makes the molecules.

18. Vacuoles (Storage Organelles) Found in all Cells and act to store food, water, enzymes, waste, etc... In Animals, they are small and primarily used in digestion along with the Lysosomes. In Plants, they are large (up to 90% cell size). They keep the cells rigid and store Water and toxic materials within the cell! Vacuole Storage! Large open structure in Plant Cells. Small and numerous in Animal Cells.

19. Mitochondria (the Mighty Mitochondria) Provides Energy for the Cell (Powerplant!). Specialized Organelle that acts to make ATP from the breakdown of food molecules. Many per cell - especially in very active cells! Have their own DNA/ribosomes. Very Active Cells require Energy and possess Many Mitochondria! Sperm Cells require as many as possible to swim as fast as possible! Mitochondrion PowerHouse! Site of Aerobic Respiration! Makes LOTS of ATP for the Cell.

20. CHLOROPLAST and Plastids (various specialized Plant Organelles) Chloroplasts –function in photosynthesis,Contain the green pigment chlorophyll. Other Plastids Store other Pigments, Fats, Complex Carbohydrates, etc… (appear to be modified Chloroplasts!) Chloroplast Photosynthesis! Green = Chlorophyll! Makes Sugar using Sunlight Energy!

21. Mitochondria and Plastids. Possess their own DNA and Ribosomes. They Reproduce Independently from the Cell. They closely resemble certain bacteria: Possible origins as Symbiotic Bacteria trapped inside eukaryotic cells long ago.

22. Cytoskeleton (Support and Organization) Network of thin, fibrous proteins that act as a Scaffold for the Organelles and Determine the Shape of the Cell. *Microtubules and *Microfilaments are the dominant protein fibers of the Cytoskeleton.

23. Cytoskeleton Cell Shape! Internal Transport! Organization of the Cell!

24. Locomotion (cytoskeleton adaptations for movement) Cilia: Short hairlike projections on the surface of cell membrane. May move the cell outright or move material located on the cell surface. Cells of the respiratory tubes (trachea here) move mucus = phlegm! Inner Ear Cells. Moving Cilia = Hearing! Paramecium use cilia to perform Locomotion!

25. Locomotion (cytoskeleton adaptations for movement) Flagella:Long Projections of the cell membrane that moves like a tail to propel the cell. Usually only a few per cell. Cilia/Flagella Locomotion and movement! Cilia Short and Numerous. Flagella long and one or few (usually)

26.   Outside the Cell Inside the Cell Plant or Animal?!

27. The Prokaryotic Cell! But, they DO HAVE?! No Nucleus! Small! Simple! First! No Organelles! A B C I R A E T