1. An Introduction to
CELLS
Jen Cook and E.Coleman 2008

3. CELL THEORY: One of the 3 Theories that unify all knowledge in Biology
1. All living things are made of one or more cells.
2. A cell is the smallest thing that can be considered alive. (1839 Schwann & Schleiden )
3. All cells come from other
pre-existing cells by reproduction.
(1855 Rudolph Virchow
Cells were first discovered in
1663 using one of the first
primitive microscopes. They
were cells in cork. Robert Hooke
[The word cell is from Latin 'cellula' which means small compartment ]

4. Microscope
1670’s Anton von Leeuwenhoek – first to observe bacteria and protozoa using a more “advanced” microscope.
~ 1833 Robert Brown reported the discovery of the nucleus

5. TYPES OF CELLS: A. Prokaryotic
SIMPLE
No nucleus or other
complex organelles.
b. DNA circular,
floating in cytoplasm.
2. TINY : .1 – 10 Mm
3. PRIMITIVE: Similar to
first living things.
Fossils found up to
3.8 billion years old.
4. KINGDOM: Monera
(example: bacteria)

6. TYPES OF CELLS: B. Eukaryotic
1. COMPLEX
Nucleus + many other complex organelles.
b. DNA in nucleus; multiple strands (called chromosomes)
2. LARGE: Mm (some up to 2 meters long!)
3.ADVANCED: Evolved almost 2 billion years after Prokaryotes.
4. KINGDOMS:all members of Protist, Fungi, Plant, Animal
5. TYPES:
a. PLANT
b. ANIMAL

7. Each cell in an organism has a specific job.
Depending on its function it may look very different from the “typical” plant or animal cell.

8. Notes: HOW EUKARYOTIC CELLS EVOLVED The Endosymbiont Theory (“Endo-” = inside; “Symbiosis” = mutually beneficial relationship)
1. Mitochondria and chloroplasts were once free-living prokaryotic organisms.
2. They entered (or were eaten by!) cells of other organisms and began living there.

9. 3. Helped host cells survive: provided ATP (mitochondria) or glucose (chloroplasts).
4. Host cell provided protection for them.
5. And so - they stayed!

10. All surrounded by double membranes.
Evidence Supporting Endosymbiont Theory – Mitochondria and Chloroplasts are very much like bacteria:
All surrounded by double membranes.
2. Similar size. a. mitochondria: Mm
b. chloroplasts: Mm
c. bacteria: 0.5 – 10Mm
E Coli (bacteria)
Chloroplast
Mitochondria

11. Evidence Supporting Endosymbiont Theory - continued
3. Similar ribosomes.
4. Both have their own DNA (separate from nuclear DNA of the cell) - circular like bacterial DNA.
5. Both reproduce separately from rest of cell - by simple fission, like bacteria.

12. Basic cell structures/organelles
Cell membrane
Cell wall (plants only)
Nucleus
Chromatin
Chromosome
Chromatids
Nucleolus
Nuclear envelope/nuclear membrane

13. Organelles, continued Cytoplasm Cytoskeleton Ribosomes Microtubules
Endoplasmic reticulum (rough and smooth)
Golgi apparatus
Lysosome
Vacuole
Chloroplast (plants only)
Mitochondria
Cytoskeleton
Microtubules
Microfilaments
(good website to learn names and functions of cell organelles)

14. CELL ANALOGY: A cell is a lot like a town
CELL ANALOGY: A cell is a lot like a town. Its organelles do jobs similar to the functions of some entities in a typical town. Which cell organelle is most like each of the following in terms of the work it does for the cell?
Master plan; blueprint.
Freeway system
Cement factory
Food producers (farmers)
Power plant, electricity generators.
6. Sewage treatment, waste detoxification
7. Water storage tank
8. Border control, INS
9. Mayor’s office
10. Materials packaging & storage
Chromatin (DNA)
Lysosome
Endoplasmic Reticulum
Vacuole
Ribosome
Cell (plasma) membrane
Chloroplast
Nucleus
Mitochondria
Golgi body

15. Review of Animal and Plant Cells
Created by T. Bun & J. Cook & E. Coleman

16. What type of cell is this?
PLANT CELL

17. What type of cell is this?
Animal
ANIMAL CELL

18. ________ are known as the “power-houses” of the cell because they produce ATP.
Nucleus
MITOCHONDRIA

19. The cell membrane is also known as the _______ membrane.
What structure controls the movement of
materials into and out of the cell?
CELL MEMBRANE
The cell membrane is also known as the _______ membrane.
PLASMA
________ are the sites where proteins are made (“protein synthesis”) in the cell.
Plasma
RIBOSOMES

20. thing plant cells store in their vacuoles?
What is number 6?
A vacuole.
What is the main
thing plant cells store in their vacuoles?
Vacuole
WATER

21. Number 5 is pointing to what?
The CELL WALL.
Cell Membrane

22. What structures produce glucose and other carbohydrates (i.e. FOOD!)?
CHLOROPLASTS
Chloroplast

23. What organelles store primarily enzymes and waste?
LYSOSOMES
Vacuoles

24. What is the structure in the nucleus that makes ribosomes and other kinds of RNA?
Nucleolus
Nucleolus

25. What is structure number 13?
PC diagram
Centrioles
CENTRIOLE

26. What type of cells are these?
Cheek Cells
HUMAN CHEEK CELLS

27. What type of cells are these?
ELODEA CELLS
What are the little green things inside them?
CHLOROPLASTS

28. What kind of cells are these?
ONION CELLS
Onions are plants. Why are there no chloroplasts in these cells?
This part of the plant grows underground. Chloroplasts do photosynthesis – that requires light. There’s no point in having chloroplasts in cells that aren’t exposed to light!

29. Number 6 is pointing to what structure?
Golgi Body
GOLGI BODY (aka GOLGI APPARATUS, GOLGI COMPLEX)

30. CHLOROPLASTS and CELL WALLS
The two structures found in plant cells that are never found in animal cells are ____________ & ___________.
CHLOROPLASTS and CELL WALLS
Cell Wall and Chloroplast

31. Name structures 1, 2, 5, & 9. NUCLEOLUS MITOCHONDRIA NUCLEUS
Nucleolus, Nucleus, ER, Mitochondia
ENDOPLASMIC
RETICULUM