Microscopes & Cells

1. Microscopes & Cells

2. Don’t copy down this slide – just listen Microscopes and Cells: History Robert Hooke • In 1663, __________ coined the term “cells” • 10 years later, _________________ observed bacteria and protozoa • In 1833, __________ observed and coined the term “nucleus” 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 • 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… Please add the above as point #4 to the cell theory

6. How big are cells? plant animal • 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? __________________ 10 100 0.2 m It is limited to the visible light spectrum Electron Microscopes

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

8. Prokaryotic Cells (cells without a nucleus) for ex. bacteria Label this diagram in your handout DNA (Nucleoid) Ribosomes Plasma Membrane Cytoplasm Cilium Cilia Flagellum Flagella 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 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 Differences and similarities between Prokaryotes and Eukaryotes

11. The Plasma Membrane (1) Carbohydrate side chains 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) Start taking notes in your table given to you in class • It is a semi-permeable barrier that allows for the passage of certain things based upon ______, _______, and _____________. • What are the forms of transport across a cell membrane? charges size solubility in fat Active and Passive Transport

13. Plasma Membrane’s Microvilli Add this to the info on plasma membrane • Microvilli are 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 feature does the following for plant cells and prokaryotes: • Provides Support • Provides Protection

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

16. SEM of a freeze-fractured nuclear membrane Nucleus and nucleolus(in eukaryotic cells) • Ribosomes are made here: • DNA andproteins form found in the nucleus • Openings in thenuclear membrane nucleolus chromatin, TEM of nuclear pores Nuclear pores

17. 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) Ribosome unit TEM of ribosomes

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

19. Golgi Apparatus (in eukaryotic cells) vesicles It is the center of Warehousing, Sorting and Shipping of Proteins ER products move here in

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

21. Mitochondria (in eukaryotic cells) takes place in this organelle. It is often called the ““ of the cell because it creates energy for the cell Cellular Respiration powerhouse

22. Chloroplasts (in plant cells) • An organelle that converts energy from the sun into chemical energy (sugar) The process is called: Photosynthesis

23. The Cytoskeleton (in all cells) • A network of fibers that extend throughout the cytoplasm, • Three types: Microtubules Microfilaments Intermediate Filaments

24. Cytoskeleton: Functions • Provides shape and support (skeletal) • Moves the organelles within the cell and helps move flagella/cilia Organelle

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

26. 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.

27. Lysosomes (in animal cells) • Membrane-bound organelle in animal cells that contains ___________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