1. Life Science
Chapter 1-2
The Cell

2. What are cells?
Smallest unit of life that exhibits all the characteristics of living things
Within cells are organelles (specialized structures)

3. Cellular Organization
Unicellular or multicellular
Specialized structures
Cell is basic unit of structure and function

4. History of Cell Research
Scholars think Robert Hooke used this microscope when he prepared Micrographia, the first book describing observations made through a microscope. The middle glass of this three-lens instrument can be removed to more closely examine a specimen.
17th century scientist Robert Hooke was the first person to use the word "cell" to identify microscopic structures, describing cork: " these pores, or cells, were not very deep, but consisted of a great many little boxes."

5. History of Cell Research
In 1673, Anton van Leeuwenhoek began writing letters to the newly-formed Royal Society of London, describing what he had seen with his microscopes -- his first letter contained some observations on the stings of bees. For the next fifty years he corresponded with the Royal Society; his letters, written in Dutch, were translated into English or Latin and printed in the Philosophical Transactions of the Royal Society, and often reprinted separately.

6. Cell Theory All plants are made up of cells.
Mattias Schleiden 1838
All plants are made up of cells.
Theodor Schwann 1838
All animals are made up of cells.
Rudolph Virchow 1858
Cells only come from other cells.

7. Plant Cell
Animal Cell

8. Cell Boundaries Plasma Membrane – semi-permeable membrane Cell Wall
Plants, Fungi, and Bacteria have this additional boundary
Located outside the plasma membrane
Provides additional support and protection (cellulose)
Allows molecules to pass through (no selection)

9. Cytoplasm
Clear, jelly-like fluid that supports the cell, site of chemical reactions, houses all of the other organelles

10. Nucleus Nucleolus Inside nucleus Makes ribosomes
Controls cell processes (making proteins is the main function of cells)
Contains DNA
Membrane surrounding nucleus has pores to allow RNA, ribosomes to exit
Nucleolus
Inside nucleus
Makes ribosomes

11. Endoplasmic Reticulum (ER)
Highly folded membranes suspended in the cytoplasm
Site of cellular chemical reactions (workbench)
2 types:
Rough ER – area on ER where ribosomes attach, make proteins and transports proteins (cellular highway)
Smooth ER – area where no ribosomes are attached, makes lipids, transports proteins, breaks down harmful substances

13. Ribosomes Found bound to rough ER and free-floating in the cytoplasm
Site of protein synthesis (protein assembly) according to directions from the nucleus

14. Golgi Apparatus Flattened system of tubular membranes
Modifies proteins by attaching carbohydrates and lipids
Sends them to appropriate place in the cell in packages called vesicles
“Post-Office”

15. Chloroplasts Only in plants Contain the green pigment Chlorophyll
Site of photosynthesis -
chlorophyll captures light energy to produce food

16. Vacuoles Sac-like structure
Plants contain 1 large one, while animals have many small
Storage of water, food and/or waste

17. Lysosomes
Contain digestive enzymes to break-down old organelles, food, viruses, and bacteria
Only animal cells
“Clean-up” crew

18. Centrioles Animal cells only Made of microtubules
Involved in cellular reproduction

19. Mitochondria Transform energy for the cell “Powerhouse”
In plants and animals
Found in varying numbers depending on the cell type (ex. Muscle cells have many)

20. Cytoskeleton Provides structure and support Works like poles of a tent
Assists organelles in moving around the cell

21. Cilia
Short, hair-like fibers (protein based) that move in a wave-like motion to propel (move) the cell or materials along surface of cell
paramecium
Tracheal cells (#3 is mucous particle)