1. Cell Structure and Function Notes
Discovery of the Cell:
Mid 1600’s scientists began using microscopes to observe living things
Robert Hooke used microscope to observe thin slice of cork—dead plant material
Cork seemed to be made of box-like chambers—Hooke called cells
Anton van Leeuwenhoek discovered
living cells in pond water

2. Cell Theory: All living things composed of cells
2. Cells are the basic unit of structure and function in living things
3. New cells are produced from existing cells

3. Cell and its Environment:
Organisms made of one cell—unicellular organisms
Ex: bacteria
Organisms made of many cells—multicellular organisms
Ex: plants, animals

4. Each cell must be in “balance” with its environment, exchange food, waste, H2O, CO2, O2 etc.
Process by which organisms maintain a relatively stable internal environment—homeostasis

5. Cell Type:
Organisms that do not have a distinct nucleus—prokaryotic (PRO = NO)
Ex: bacteria
Organisms with cells that have true nucleus and organelles—eukaryotic (EU = TRUE)
Ex: plants, animals, fungi

6. Levels of Organization
Cell
Tissue
Organ
Organ System
Organism

7. Cell Parts and Their Functions:
Specialized cell parts called organelles— “little organs”

8. Cell membrane (phospholipid bilayer)—determines what goes in and out of the cell aka “gate keeper”

9. Cytoplasm (cytosol)—gel-like medium that holds the organelles in position

10. 1. Nucleus—control center of the cell
Double membrane that surrounds the nucleus—nuclear membrane
Genetic information inside the nucleus stored as—chromatin (DNA)

11. Nucleolus – small dense region in the nucleus
Nucleolus – small dense region in the nucleus. Site of ribosome production
Nuclear Envelope – double membrane with pores, which allow RNA to leave the nucleus.

12. Ribosomes— located on the rough ER or in the cytosol
Ribosomes— located on the rough ER or in the cytosol. Site of protein synthesis

13. Rough Endoplasmic Reticulum (rough ER)— Extensive network continuous with the nuclear envelope.
Called rough ER because of the ribosomes found on its surface

14. Rough ER Continued…
Function: to modify & transport proteins
Proteins then packaged into vesicles and sent to the Golgi Apparatus

15. Smooth Endoplasmic Reticulum (smooth ER)—Manufactures and transport lipids and other materials within the cell. Breaks down glycogen, detoxifies poisons, and stores calcium.
Called smooth ER because it lacks ribosomes found on its surface

16. Golgi apparatus
Flattened, round sacs that look like a stack of _pancakes_____. Receives, modifies, and ships Endoplasmic Reticulum products (proteins and other substances) by way of _vesicles____ into the _cytosol then to the cell membrane.

17. Found in animal cells only:
Lysosomes—cleans up the cell and
digests unwanted materials by containing enzymes that breakdown and recycle used cell components.
Used as a defense against bacteria and viruses

18. Vacuoles—sac-like structures may be used as storage for water, molecules, or wastes.
Plant cells usually contain a large vacuole that fills most of the cell—pressure (AKA turgor pressure) from this large vacuole helps plants support themselves

19. Mitochondria—energy source of the cell (powerhouse – “Mighty mitochondria”)
Double-walled organelle with inner folds to increase surface area. Uses glucose to manufacture energy in the form of ATP. Mitochondria have their own DNA.

20. Found in plant cells only:
Cell wall—provides support and
protection for cell
Composed mainly of cellulose —fiber for our diet
Chloroplast— contain chlorophyll and their own DNA. makes glucose using the energy from the sun (photosynthesis)

21. Centrioles
Found in animal cells only. Bundles of microtubules that play a role in cell division

22. Cytoskeleton
Composed of protein fibers known as microtubules and microfilaments. Anchor organelles and provide structure. Also provide motility for some cells in the form of cilia or flagella. More extensive cytoskeleton found in animal cells.

23. Specialized Parts for movement:
1. Cilia (like little hairs) 2. Flagella (like a tail)
Found on prokaryotic and eukaryotic cells.

24. Specialized Cells:
Different cells in your body do different jobs. The structure (how it’s built) of cells matches the function (what it does).

25. Plant Examples:
Leaf cell—contains many chloroplasts to maximize photosynthesis
Root cell (potato)—contains many vacuoles to maximize water and starch storage

26. Animal Examples:
Epithelial cells—have villi to increase nutrient absorption; found in the intestines
chloroplast

27. 2. Muscle cells—contain many mitochondria to produce more energy for movement

28. 3. Nerve cells—have fibers called dendrites
3. Nerve cells—have fibers called dendrites that allow nerve cells to communicate with each other

29. A deeper look into cells…
Inside of Cell
Cell Parts Description and Animation

30. Plant cells vs. Animal Cells
Both