1. Cell Structure and Function

2. The discovery of cells and The Cell Theory
Anton van Leewenhoek-given credit for inventing the first microscope
Robert Hooke-first used the word cell
He was looking at cork cells

3. Robert Brown-discovered the nucleus
Mathias Schleiden-a botanist,
he said all plants are made of cells
Theodor Schwann-all animals
are made from cells

4. Rudolf Virchow-studied reproduction in cells and found all cells come from other cells

5. Cell theory: all living things are made up of cells
cells come from other cells
cells are the basic unit of life

6. There are 2 types of cells: prokaryotic and eukaryotic cells
Prokaryotic cells-do not have a nucleus, the DNA is free in the cell. Prokaryotic cells are very small and do not have most cell structures. Example: bacteria cells

7. Eukaryotic cells-contain a nucleus which holds the DNA together
Eukaryotic cells-contain a nucleus which holds the DNA together. They have many cell structures and are much larger cells. Example: all other cells (plants, animals, fungi)

8. Major cell structures:
1. Cell membrane-holds cell together, controls what enters and leaves
made of 2 layers of lipids
proteins embedded throughout

9. 2. Nucleus-means ”center”, usually appears darker, acts as control center
surrounded by a nuclear envelope
contains DNA which is our
genetic information

10. 3. Cytoplasm-all the material between the cell membrane and the nucleus
It is a jelly like material
It holds all the cell organelles in place but still allows movement

11. Cell wall-found in plants, most bacteria and fungi.
Provides support and protection for the cell
Made of cellulose (a combination of sugar and protein)
Nucleolus-found inside the nucleus, it makes the ribosomes

12. Cytoskeleton-framework inside cell for support and strength
microtubules-hollow tubes made of protein, form the centrioles
microfilaments-long thin fibers, movement and support
cilia-short hairlike structures on outside of cell for movement
flagella-long hairlike structures on outside of cell for movement

13. Ribosomes-small bead like structures that make proteins
may be free or attached to ER

14. ER-endoplasmic reticulum-folded membrane
forms a canal for materials to leave cell
Smooth-no ribosomes attached
Rough-has attached ribosomes

15. Golgi apparatus-look like flattened sacs, modify and package materials to leave cell
Lysosomes-small sacs with enzymes that digest food , foreign material or the entire cell when it wears out

16. vacuoles-sacs that hold waste, food, water: storage centers
plants have 1 large one in the center
animals have several small ones

17. Chloroplast-contain the green pigment chlorophyll
produce sugar from sunlight
found in plant cells only

18. Mitochondria-power house: breaks down food for energy
certain cells, like brain and muscle cells, may have thousands

19. centriole-found only in animal cells, help the cell to divide, cell has two

20. Plant cells Animal cells
Have a cell wall
Have chloroplasts
Do not have centrioles
Have one large vacuole
Do not have lysosomes
Do not have a cell wall
Do not have cloroplasts
Have centrioles
Have several small vacuoles
Have lysosomes

21. Movement through the cell membrane
The environment of the cell is liquid inside and out. The liquid contains dissolved materials (solutes) These materials are always in motion This motion is random but follows the rule of moving from high to low concentrations.

22. Methods of movement: I. Passive-no energy is required by the cell
A. Diffusion-the random movement of materials from high to low concentration. It continues until equilibrium is reached

23. B. Osmosis-the movement of water across a membrane from high to low concentration. C. Facilitated diffusion-carrier proteins found in the cell membrane transport material across the membrane (still moving from high to low)

24. II. Active transport-movement that requires energy
A. Endocytosis-moving material into the cell
1. phagocytosis-Greek for “eat”, cell engulfs large particles, vacuole forms around food
example-WBC eating
bacteria in the body

25. 2. Pinocytosis-Greek for cell that drinks. The
cell surrounds a large amount of water and
forms a vacuole.

26. B. Exocytosis-moving materials out of the cell
a vacuole moves to the cell membrane, it opens and material is pushed out

27. Specialization of cells
Unicellular organisms-the cell is the entire organism. It carries on all life functions.
Multicellular organisms-cells are interdependent on each other.
They have specialized to do different jobs.

28. Specialization-cells carry out different jobs for the organism
Examples-
Pancreas cells make the protein insulin so they have a lot of ribosomes and ER
Respiratory cells have cilia and make mucus to keep foreign material out of lungs

29. Levels of organization in multicellular organisms:
cells tissue organ system
muscle cell muscle tissue stomach digestive
muscle cell muscle tissue heart circulatory