Honors Biology Cell Structure Webquest Worley Name: ________________________________ Section 1. Cell Theory: Navigate to: http://www.bio.miami.edu/~cmallery/150/unity/cell.text.htm#milestones 1. When and by whom was the cell theory formally articulated? Matthias Schleiden and Theodore Schwann in 1839 2. What are the 6 modern tenets of the cell theory? (Put stars next to the first 3). 1. all known living things are made up of cells. 2. the cell is structural & functional unit of all living things. 3. all cells come from pre-existing cells by division. (Spontaneous Generation does not occur). 4. cells contains hereditary information which is passed from cell to cell during cell division. 5. All cells are basically the same in chemical composition. 6. all energy flow (metabolism & biochemistry) of life occurs within cells. 3. Describe the collaboration between Schleiden and Schwann. Schwann and Schleiden met over coffee. Schleiden described his observations of plant cells, and Schwann was struck by the similarities of Schleiden’s observations with his own of animal cells. The two men immediately looked at slides of cells, confirmed the similarities between the cell types. Schwann published his findings about plant and animal cells in 1839. He did not give credit to Schleiden for his contributions. 4. Who enunciated the dictum "Omnis cellula e cellula?” Rudolf Virchow 5. What does this dictum mean? All cells arise from pre-existing cells. 6. Who is credited with the development of the first compound microscope? Zacharias Jansen 7. Who coined the term cell? Where does the term come from (root word & meaning)? Robert Hooke, from the Latin word cellula meaning small compartments 8. Since cork cells are dead (cells of trees), what did Hooke actually observe? The cell walls of the cells. (They had no cytoplasmic contents) 9. Anton von Leeuwenhoek (a Dutch business man) developed his own monocular microscope which magnified 200x, and produced clearer and brighter images than his colleagues at the time. What allowed him to have such success? (Be specific and include all mentioned reasons). “Leeuwenhoek's skill at grinding lenses, together with his naturally acute eyesight and great care in adjusting the lighting where he worked enabled him to build microscopes that magnified over 200 times, with clearer and brighter images than any of his colleagues at that time.” 10. Leeuwenhoek’s discoveries are numerous. List 5 here. “Leeuwenhoek looked at animal and plant tissues, at mineral crystals, and at fossils. He was the first to see microscopic single celled protists with shells, the foraminifera, which he described as "little cockles. . . no bigger than a coarse sand-grain." He discovered blood cells, and was the first to see living sperm cells of animals. He discovered microscopic animals such as nematodes (round worms) and rotifers.” Part II. Plant and animal Cell Structure and Function. Navigate to cellsalive.com *Click on cell model *choose either the plant or animal cell model and label the corresponding diagram. Using the word bank, label the correct structures on the diagram below. Cell A Cell B Mitochondria Cytoskeleton Smooth endoplasmic reticulum Cell membrane Rough endoplasmic reticulum vacuole Golgi apparatus Nucleus Vacuole Cell wall cell membrane Chloroplast 1. Is cell A a eukaryotic or prokaryotic cell? HOW DO YOU KNOW? Cell A is a eukaryotic cell. We know this because the cell contains a nucleus and other membrane bound organelles. 2. Is cell B a eukaryotic or prokaryotic cell? HOW DO YOU KNOW? Cell A is a eukaryotic cell. We know this because the cell contains a nucleus and other membrane bound organelles. 3. Is cell A or B the plant cell? Give three reasons to support your answer. (The differences between plant and animal cells) Cell A is an animal cell. It does not have a cell wall or chloroplasts, and it does not have a large central vacuole. Part III. Matching Plant and animal organelle function. *Click on structures under cell model to find descriptions of organelle function mitochondria golgi (apparatus) lysosome chloroplast cytosol peroxisome nucleus Rough endoplasmic reticulum cell wall smooth endoplasmic reticulum cell membrane vacuole cytoskeleton (includes microfilaments & microtubules) nucleolus centrosome secretory vesicles 1. lysosome This organelle produces enzymes necessary for intracellular digestion. For example, in white blood cells this organelle’s contents are released to kill bacteria. 2. cell wall The organelle which is responsible for giving the cell shape, protecting it, and controlling what goes in and out of the cell. Found in plant, fungi, and bacteria cells, but NOT animal cells. 3. smooth endoplasmic reticulum This organelle has a variety of functions, depending on what type of cell it is found in. For instance, in liver cells it is responsible for breaking things down, whereas in muscle cells it is involved in calcium release for muscle contraction. 4.vacuole The organelle where water, waste products, and nutrients are stored. This organelle is much larger in plant cells than in animal cells. 5. cell membrane This organelle is the “gatekeeper” of the animal cell. It controls what comes in and out of the cell. 6. mitochondria The organelle in which energy is produced. The powerhouse of the cell. 7.peroxisome Protects the cell from its own production of toxic hydrogen peroxide. 8. cytosol The liquid gel-like substance in the cell. 9. nucleolus This organelle produces ribosomes. 10. centrosome Where microtubules are produced. Also, responsible for the production of spindle fibers during cell division. 11. chloroplast The organelle where photosynthesis takes place. Found in autotroph cells. 12. cytoskeletonThis organelle gives the cell shape, and is involved in cell division. 13. golgi apparatus This organelle is responsible for packaging and transport in the cell of the hormones and enzymes contained in the lysosomes, peroxisomes and secretory vesicles. 14. rough endoplasmic reticulum This organelle is located next to the nucleus, and is studded with ribosomes. Proteins produced on the ribosomes on this organelles surfaces are transported through this organelle for transport throughout the cell. 15. nucleus The control center of the cell. Where the DNA is housed. 16. secretory vesicles Cell secrections (for example, hormones and neurotransmitters are packaged in these organelles at the Golgi apparatus and then released at the cell’s surface). Part IV. Bacteria Cell Structure 1. Click on cell models & Scroll down 2 Click on take me to the Bacteria cell model Label the following structures on the following bacterium cell pilus cell wall flagella ribosome DNA (nucleoid) Pilus nucleoid pilus ribosome flagella Cell membrane cell wall capsule 1. Is the above cell a prokaryotic or eukaryotic cell? HOW DO YOU KNOW? Part V. Matching Bacterial Cell Functions *Descriptions below cell model Nucleoid Flagella Nucleoid Ribosomes Storage Granules Endospore Capsule Outer membrane Cell wall Pili Plasma Membrane **Nucleoid DNA in the bacterial cell is generally confined to this central region. **Ribosome Where proteins are synthesized Storage granules Nutrients and reserves in the form glycogen, lipids, or polyphosphate molecules stored in the Endospore spores that are highly resistant to drought, high temperature and other environmental hazards, and can produce new bacteria populations. EX: Clostridium botulinum capsuleLayer of polysaccharide (or sometimes proteins) which protects the bacterial cell and is often associated with pathogenic bacteria because it serves as a barrier against phagocytosis by white blood cells. ***Don’t need to know***Outer membrane This lipid bilayer is found in Gram negative bacteria and is the source of lipopolysaccharide (LPS) in these bacteria. Cell wall Composed of peptidoglycan (polysaccharides + protein), the cell wall maintains the overall shape of a bacterial cell. The three primary shapes in bacteria are coccus (spherical), bacillus (rod-shaped) and spirillum (spiral). Mycoplasma are bacteria that have no cell wall and therefore have no definite shape. Plasma membrane (Cell membrane) This is a lipid bilayer much like the plasma membrane of other cells. There are numerous proteins moving within or upon this layer that are primarily responsible for transport of ions, nutrients and waste across the membrane. Pili Hairlike structures made of protein which allow bacteria to attach to other cells. Flagella Long appendages which allow the bacterium to move.