• Cell Theory

    Cell Theory Cell Theory
     
     The Building Blocks of Life
    Robert Hooke – 1665
    • Used a “microscope” / magnifying glass to look at cork
    • From England
    • Discovered what a cell was by looking at a piece of cork
     
    Anot Van Leeuwenhook – 1673
    • Dutch inventor who created the microscope that we recognize today
    • First person to discover a single celled protozoa
      • Protozoa is like pond scum
    • He also looked at blood cells
     
    Cell:
    The smallest unit of life that can perform all life processes.
    Cell Theory (Really important - Know This!)
    • All organisms are made of one or more cells
    • The cell is the basic unit of all living things
    • All cells come from existing cells
    Spontaneous Generation:
    • The idea that things or organisms just appear.
      • AKA – The idea that worms were created out of rain hitting the ground or the idea that flies came from dirty rags and filth.
    Protoplasm:
    All the living material found in a cell capable of carrying on all the life processes.
    The Two Major Kinds of Cells:
    Prokaryote Cell: (1st Major Kind of Cell)
    Cells that DO NOT have a cell membrane around their nucleus.
    Example – Bacteria
    • Prokaryotes are molecules surrounded by a membrane and cell wall. Prokaryotic cells lack characteristic Eukaryotic sub cellular membrane enclosed “organelles”, but may contain membrane systems inside a cell wall.

    Second kind of Prokaryotes: 

    Archaebacteria
    • SAME As bacteria since they lack a nucleus and don’t have membrane bound organelles.
    • DIFFERENT in that they have ribosomes that are more like a Eukaryotic cell.

    Eukaryotic Cell (2nd Major Kind of Cell)
    Cells that have a membrane around their nucleus.

    Example – Plant and Animal Cells Eukaryotic

    Cells usually are 10 times larger than Prokaryote cells.

    The basic Eukaryotic cell contains the following:

    1. Plasma membrane around their nucleus
    2. Cytoplasm (the semi fluid substance inside the membrane.
    3. Has a cytoskeleton – the microfilaments and microtubules that suspend organelles, this gives it shape, and allow for the cells motion.
    4. Has membrane enclosed subsellular organelles.
    Parts of the Cell:
    Organelles:

    The things or structures (PARTS) inside of a cell that perform the functions necessary for the cell to survive.

    • Example: Think about your heart, lungs and liver… They are all organs or organelles inside of your body. The cell has parts like this inside of its cell.
    Cell Membrane:

    Is the protective layer that covers the cell’s surface.

    it acts like the fence around a yard. It is like the skin on your body. It keeps some things out and lets some thing in.

     

    Location:
    • Found in all cells
    Description
    • Plant - inside cell wall
    • Animal - outer layer; cholesterol
    • Double layer of phospholipids with proteins
    • Selectively permeable
    Function
    • Support
    • Protection
    • Controls movement of materials in/out of cell
    • Barrier between cell and its environment
    • Maintains homeostasis
    Cell Wall:
    • Found only in PLANT cells
    • Gives support to the cell
    • Is a second layer or “fence” like the cell membrane.

     

     
    Location:
    • Plant, Fungi, & Bacteria, but not animal cells
    Description
    • Outer layer
    • Rigid & strong
    • Made of cellulose
    Function
    • Support (grow tall)
    • Protection
    • allows H2O, O2, CO2 to diffuse in & out of cell
    Nucleus:
    • An organelle inside of the cell that directs the activity in the cell.
    • It holds the DNA (Deoxyribonucleic acid)
      • This is the blue print material (directions) for the cell.
      • It tells how to reproduce and perform all of the cells jobs.
     

    nucleolus

     

    Location:
    • All cells except prokaryotes
    Description
    • Found inside the cell's nucleus
    • May have more than one
    • Disappear during cell division
    Function
    • Make ribosomes

    Nuclear Membrane 

     
    Location:
    • All cells except prokaryotes
    Description
    • Surrounds nucleus
    • Double membrane
    • Selectively permeable
    Function
    • Controls movement of materials in/out of nucleus
    Endoplasmic Reticulum: (ER)
    • A folded membrane that moves material in the cell
    • ER (Endoplasmic Reticulum) is part of the internal delivery system and uses tubes for passageways.
    • ER is additionally responsible for moving proteins and other carbohydrates to the Golgi Body.

    Location:
    • All cells except prokaryotes
    Description
    • Network of tubes or membranes
    • Smooth w/o ribosomes
    • Rough with embedded ribosomes
    • Connects to nuclear envelope & cell membra
    Function
    • Carries materials through cell
    • Aids in making proteins

     

    Golgi Body (Apparatus)

    • consisting of flat, disk-shaped sacs, tubules, and vesicles
    • Stacks of sacs that package and move proteins around in the cell.

    Location:
    • All cells except prokaryotes
    Description
    • Stacks of flattened sacs
    Function
    • Modify proteins made by the cells
    • Package & export proteins
    Mitochondria
    • The organelle that releases energy in the cell. (The powerhouse of the cell)
    • Found in both animal and plant cells.
    • Mitochondria produce ATP using energy stored in food molecules.

    Location:
    • All cells except prokaryotes
    Description
    • Peanut shaped
    • Double membrane
    • Outer membrane smooth
    • Inner membrane folded into cristae
    Function
    • Breaks down sugar (glucose) molecules to release energy
    • Site of aerobic cellular respiration
    Chloroplasts
    • Organelle that produces chlorophyll. ( The chemical of photosynthesis) to power the plant cell.
      • Chlorophyll traps the energy of sunlight, which is then used by the plant cell to make sugar for energy.
    • Only found in PLANT cells.
    Location:
    • Plants and algae
    Description
    • Green, oval containing chlorophyll (green pigment)
    • Double membrane with inner membrane modified into sacs called thylakoids
    • Stacks of thylakoids called grana & interconnected
    • Gel like innermost substance called stroma
    Function
    • Uses energy from sun to make food (glucose) for the plant
    • Process called photosynthesis
    • Release oxygen

    Ribosome:

    Organelle that makes protein for the cell.

     

    Location:
    • All cells
    Description
    • Small bodies free or attached to ER
    • Made of rRNA & protein
    Function
    • Synthesizes proteins

    Vesicle / Vacuole

    Small sack that moves material in and out of the cell.

     

    Location:
    • Plant cells have a single, large vacuole
    • Animal cells have small vacuoles
    Description
    • Fluid-filled sacs
    • Largest organelle in plant cells
    Function
    • Store food, water, metabolic & toxic wastes
    • Store large amounts of food or sugars in plants
    Lysosome:
    • Organelle that eats worn out cell parts.
    • It contains digestive enzymes.
    • Lysosomes are round membrane surrounded structures that can be found anywhere in the cytoplasm.
    • Sometimes they are called suicide bags because they encase the worn out part that is to be digested.

     

    Location:
    • Animal as well as plant cells
    Description
    • Small and round with a single membrane
    Function
    • Breaks down larger food molecules into smaller molecules
    • Digests old cell parts
    Cytoplasm
    • The gel-like material inside of the cell membrane.
    • Keeps organelles in place

     

    Location:
    • All cells
    Description
    • Clear, thick, jellylike material (cytosol)
    • Organelles found inside cell membrane
    • Contains the cytoskeleton fibers
    Function
    • Supports and protects cell organelles

    Cytoskeleton: 

    Location:
    • All cells
    Description
    • Made of microtubules - microfilaments
    Function
    • Strengthen cell & maintains the shape
    • Moves organelles within the cell

    Centrioles

    Description
    • Paired structures near the nucleus
    • Made of a cylinder of microtubule pairs
    Function
    • Separate chromosome pairs during mitosis

     

    Location:
    • Bacterial cells & Protozoans
    Description
    • Arrangement of microtubules
    • Long, but few in number
    Function
    • Movement

    Cilia

    Location:
    • Animal cells, Protozoans
    Description
    • Arrangement of microtubules
    • Short, but numerous
    Function
    • Movement
    • Cells lining the human upper respiratory tract are ciliated (have cilia). The cilia move mucous and debris upward to the mouth where it is swallowed

    http://school.discoveryeducation.com/lessonplans/interact/vemwindow.html  (compound Virtual)

    http://www.sheppardsoftware.com/health/anatomy/cell/index.htm

    http://web.archive.org/web/20060515114541/http://koning.ecsu.ctstateu.edu/cell/cell.html

    http://web.archive.org/web/20060108043356/http:/www.wellesley.edu/Biology/Courses/110/Animal/animal.html

    http://www.harcourtschool.com/activity/cell/cell.html

    http://www.centreofthecell.org/interactives/exploreacell/index.php

    http://www.centreofthecell.org/games/

    http://www.kongregate.com/games/CellCraft/cellcraft  (WAY COOL GAME_CHECK IT OUT!!)

    http://www.nobelprize.org/educational/medicine/2001/cellcycle.html

    http://www.wisc-online.com/Objects/ViewObject.aspx?ID=AP11403

    http://www.udel.edu/biology/ketcham/microscope/scope.html  (virtual electron)