FC: The wonderful Micro-World of Cells By: Michaela Charlton
1: It's ancient history.... | The cell was first discovered by Robert Hooke in 1665 while looking at a cork under the first microscope.
2: (cork under scope) Robert observed tiny room like structures | But he only saw the cells outer walls because his sample of cork was not alive.
3: What are these....?
4: This is a bacteria cell. It is a prokaryote cell (single cell with no nucleus.)
5: As you can see the tail, this helps the bacteria move.
6: The squiggly object in the middle of the cell is its nucleolus and it holds its DNA.
7: The little "feelers" on the outside of the cell are called pilus and help the bacteria attach to other cells.
8: This is an animal cell. | It is Eukaryote cell (which is an evolved form of the bacteria cell.
9: It is very organized and has organelles to help the cell function.
10: To tell that this cell is an animal cell, it is spherical
11: This is a plant cell. It is also a eukaryote cell.
12: To roughly tell a cell is a plant cell, it is usually shaped cube-ishly
13: So what's the difference
14: The first thing is that bacteria is a prokaryote. Which means it does not have a nucleus or any organelles. Where as a eukaryote (or an animal or plant cell)is has a nucleus and organelles.
15: Where as both a a plant and an animal cell are eukaryote. But, they still are not exactly the same. A plant cell is cube-ish where an animal cell is spherical.
16: As I explain all the organelles and things that make up all the cells, look for differences in the plant and animal organelles.
17: The nucleus is basically the brain of the cell. It also holds the DNA of the cell.
18: DNA is what determines what type of cell the cell is and what the cell looks like. It is what determines a liver cell from a muscle cell, etc.
19: A chromosome is an organized structure of DNA and protein that is found in cells.
20: In a prokaryote instead of a nucleus there is a nucleolus which produces ribosomes.
21: Organelles are everything inside the cell that helps the cell function.
22: Plant cells have a rigid, protective cell wall. The cell wall provides and maintains the shape of these cells and serves as a protective barrier.
23: The cell membrane is the separates the interior of all cells from the outside environment.
24: Cytoplasm is the "soup" which helps hold all the organelles and helps the cells metabolism.
25: Ribosomes are packets of RNA and protein that play a crucial role in both prokaryotic and eukaryotic cells. They are the site of protein synthesis.
26: Mitochondria provides the energy a cell needs to move, divide, produce secretory products, contract - in short, they are the power centers of the cell
27: The cytoskeleton helps to maintain cell shape. But the primary importance is in cell motility.
28: Vacuoles tend to be large in plant cells and play several roles: storing nutrients and waste products, helping increase cell size during growth
29: Lysosomes contain enzymes that are necessary for digestion inside the cell.
30: Flagella is a tail-like projection that protrudes from the cell body of eukaryotic cells. It is what basically moves the bacteria. | The cilia is typically serve as sensory organelles.
31: Chloroplast is what gives the plant its green color.
32: Centrioles are a ring of nine groups of fused microtubules. There are three microtubules in each group. Help stabilize the cytoskeleton
33: The endoplasmic reticulum- rough-helps send the ribosomes throughout the cell. (smooth)- helps lipid and steroid hormone synthesis, breakdown of lipid-soluble toxins in liver cells, and control of calcium release in muscle cell contraction.
34: The golgi apparatus a stack of membrane-bound vesicles that are important in packaging macromolecules for transport elsewhere in the cell.
35: ~References~ www.wikipedia.org cellsalive.com www.yahoo.com