1. Microscopes & Cells

2. Microscopes and Cells: History
Don’t copy down this slide – just listen
Microscopes and Cells: History
In 1663, __________ coined the term “cells”
10 years later, _________________ observed bacteria and protozoa
In 1833, __________ observed and coined the term “nucleus”
Robert Hooke
Anton van Leeuwenhoek
Robert Browne

3. Guten Tag, Dr. Shwann
Cell Theory: History
Guten Tag, Dr. Schleiden
It appears we have come up with a very similar theory…
In 1838 (and 1839) German scientists, ________________ & ________________ independently came up with the “Cell Theory”
Matthias Schleiden
What shall we call this theory?
Theodore Schwann

4. Cell Theory Do you agree?
All living things are composed of one or more cells.
Cells are organisms' basic units of structure and function.
Cells form by free-cell formation, similar to the formation of crystals (spontaneous generation).
Do you agree?

5. all cells must come from pre-existing cells.
In 1855, German physician Rudolph Virchow discovered that…
all cells must come from pre-existing cells.
Please add the above as point #4 to the cell theory

6. How big are cells? Eukaryotic cells include _______ & _______ cells.
Most eukaryotic cells are between __ and ___ m.
What is the limit of the light microscope?
Why?
What is used to see smaller objects? __________________
plant
animal 10
100
0.2 m
It is limited to the
visible light spectrum
Electron Microscopes

7. Electron Microscopy
___________ Electron Microscopes (TEM) emit light through a thin piece of heavy metal ion stained tissue
________ Electron Microscopes (SEM) reflect light off of a piece of heavy metal ion stained tissue
Transmission
Scanning

8. Prokaryotic Cells (cells without a nucleus) for ex. bacteria
Label this diagram in your handout
DNA (Nucleoid)
Ribosomes
Plasma Membrane
Cytoplasm
Cilia
Cilium
Flagella
Flagellum
TEM of a bacterium

9. Eukaryotic Cells (cells with a nucleus)
Plant cell
Animal cell
Eukaryotic cells include both plants and animal cells

10. Differences and similarities between Prokaryotes and Eukaryotes
Prokaryotes lack:
True nucleus
Membrane bound organelles
Prokaryotes are much smaller than eukaryotes (prokaryotes are ~1 – 10 m and eukaryotes are 10 – 100 m )
Similarities
Both have:
DNA
Cytoplasm
Ribosomes
Plasma Membrane

11. The Plasma Membrane (1) Carbohydrate side chains Proteins
Don’t copy down this slide – this is just review
Proteins
Hydrophilic Region
Hydrophobic Region
Hydrophilic Region
Phospholipid
TEM of a red blood cell

12. The Plasma Membrane (in all cells)
It is a semi-permeable barrier that allows for the passage of some things based upon ______, _______, and _____________.
size
charges
solubility in fat

13. Plasma Membrane’s Microvilli
Fingerlike-projections from the cell’s membrane that increase the surface area.

14. Cell Wall (in plant cells and prokaryotic cells)
cell membrane
Surrounding the , this 1. provides support 2. protects plant cells and prokaryotes

15. Cytoplasm (in all cells)
The jelly-like fluid that holds all organelles within the cell

16. Cilia and Flagella (in all cells)
Hair-like projections that aide in movement
Cilia are shorter, more numerous and move back & forth
Flagella are longer & move in a snake-like motion.

17. Nucleus and nucleolus (in eukaryotic cells)
SEM of a freeze-fractured nuclear membrane
Nucleus and nucleolus (in eukaryotic cells)
_________make ribosomes here:
Nucleus holds DNA wrapped around proteins that form ________
____________, allow things to pass into and out of the nucleus
Nucleolus
chromatin
Nuclear pores
TEM of nuclear pores

18. Ribosomes: (in all cells) Function in
protein synthesis (formation)
Proteins made by free ribosomes stay in the cell
Proteins made by attached ribosomes are shipped out of the cell or sent to the membrane
Free ribosomes
Attached ribosomes (on ER)
TEM of ribosomes
Ribosome unit

19. Endoplasmic Reticulum (in eukaryotic cells)
There are two types:
ER has ribosomes attached.
Modifies & transports proteins
ER does not have ribosomes on it.
Makes
Breaks down carbohydrates
Detoxifies drugs & poisons
Rough
Smooth
lipids (fat)

20. Vesicles (in eukaryotic cells)
Organelles that transport proteins from the ER to the golgi and eventually to the plasma membrane

21. Golgi Apparatus (in eukaryotic cells)
_______ carrying protein from the ER move here.
Vesicles
It sorts, packages, and ships these proteins outside the cell or to the membrane.

22. Mitochondria (in eukaryotic cells)
Cellular Respiration
takes place here.
It is the “____________” of the cell because it creates energy using oxygen.
powerhouse

23. Chloroplasts (in plant cells)
This changes energy from the sun into chemical energy (sugar) in a process is called
photosynthesis

24. The Cytoskeleton (in all cells)
3 types: microtubules, microfilaments, and intermediate filaments

25. The Cytoskeleton (in all cells)
Provides shape and support (skeletal)
2. Moves the organelles within the cell and helps move flagella/cilia
Organelle

26. Centrosome (in eukaryotic cells) and Centrioles (in animal cells only)
Centrosomes make microtubules (cytoskeleton).
In animal cells, a pair of structures called (made of microtubules) help in cell division.
centrioles
Centrosome (halo)
centrioles

27. Lysosomes (in animal cells)
Special vacuole in animal cells with _________ enzymes that help clean-up the cell
Lysosome engulfing a worn-out organelle
digestive

28. Vacuoles (in eukaryotic cells)
Large, central organelle in plants
Stores water and waste products
In animals, it stores food and is small in size compared to plant vacuoles