1. The Basic Unit of Life Sections 3.1 and 3.2
Cells
The Basic Unit of Life
Sections 3.1 and 3.2

2. Cell History Cytology- study of cells
1665 English Scientist Robert Hooke
Used a microscope to examine cork (plant)
Hooke called what he saw "Cells"

3. Cell History Robert Brown Matthias Schleiden Theodor Schwann
discovered the nucleus in 1833.
Matthias Schleiden
German Botanist
1838
Concluded that all plants are made of cells
Theodor Schwann
Concluded that all animals are made of cells

4. Cell History Rudolf Virchow 1855, German Physician
New cells could be produced only from the division of existing cells
The combined work of Schleiden, Schwann, and Virchow make up the modern CELL THEORY.

5. The Cell Theory states that:
1. All organisms are composed of cells.
2. Cells are the basic units of structure and function in all organisms.
3. All cells arise from other cells.

6. Variety of Cells Single-celled bacteria are the smallest.
The largest cell is the ostrich egg.
Cells exist in a variety of shapes.
Structure is closely related to function.
All cells contain a cell membrane, cytoplasm and genetic material.

8. Prokaryotic Cells Prokaryotic cells lack membrane-bound organelles.
Single-celled
Bacteria

9. Eukaryotic Cells Eukaryotic cells contain membrane-bound organelles.
Single-celled or multicellular.
Protists, fungi, plants and animals.

10. Endoplasmic reticulum
Compare and Contrast
Prokaryotes
Eukaryotes
Cell membrane
Contain DNA
Ribosomes
Cytoplasm
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton

11. Cell Membrane—security gate
Also called the plasma membrane
Encloses a cell and separates its contents from its surroundings.
Phospholipid bilayer embedded with proteins.
Structure allows for the passage of materials into and out of the cell.

12. DNA and Chromosomes All cells contain DNA, the hereditary material.
The DNA of eukaryotic cells is organized into chromosomes and contained in a nucleus.
The DNA of prokaryotic cells is circular.
It is found within the cytoplasm.

13. Ribosomes—assembly line workers
Since DNA encodes for the formation of proteins, both eukaryotic and prokaryotic cells contain ribosomes.
Ribosomes are the sites of protein synthesis.

14. Cell Wall—security fence
Functions to protect and support the cell.
Prokaryotes, plants, fungi and some protists
Cellulose – Plants
Chitin – Fungi
Peptidoglycan - Bacteria

15. Membrane-Bound Organelles
Tiny structures that perform specialized functions in the cell.
Found in eukaryotic cells only.
Work together like departments in a factory.

16. The Nucleus—manager
Contains the DNA that directs all of the activities of a living eukaryotic cell.
Often the largest and most easily seen organelle.
Many nuclei exhibit a darker area called the nucleolus, which is a region where ribosomes are made.

17. Endoplasmic Reticulum—transport system
Series of membranes
Function as the cell’s internal transport system.
Smooth ER—important role in building lipids
Rough ER—has ribosomes attached to it

18. Golgi Apparatus—shipping department
Responsible for the storage and packaging of chemicals that are eventually secreted from the cell.

19. Lysosomes—recycling center
Loaded with strong enzymes
Digest large particles found in the cell

20. Mitochondria—power station
Release energy from the nutrients taken into the cell
Composed of a series of two membranes, which greatly increases the internal surface area.

21. The Vacuole—storage area
Bubble-like organelles
Store water, waste materials or food particles
Many plant cells contain a large, central vacuole.

22. Chloroplasts--cooks Contain the green pigment, chlorophyll
Sites of photosynthesis, or food production, in plants and algae

23. Cytoskeleton—interior walls
Network of protein fibers that reinforce the cytoplasm of eukaryotic cells
Support and shape cell
Anchor organelles to fixed locations

24. Centrioles—assembly line worker
Function during cell division
Move chromosomes

25. Plant vs. Animal Cell
Section 7-2

26. Endoplasmic reticulum
Venn Diagrams
Compare and Contrast
Animal Cells
Plant Cells
Centrioles
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts
Large Central
Vacuole