1. Filling In The Blanks: -Cell theory & 2 types of Cells -Cellular energy -Enzymes effect on Chemical Rxns (AP only)

2. Learning Objectives: What is Cell Theory
How was Cell Theory reached by scientists? (Pre-AP)
What is Cell Theory
What are some exceptions to Cell Theory
Describe in detail how Prokaryotes compare to Eukaryotes
What is the job of ATP in cells
Why can ATP perform that job

3. Cell Theory: The Men of the microscopes
Pg 170
Anton Van Leeuwenhoek (1600’s)
Credited for the first microscope (made ~500)
Looked at pond water and saw “wee beasties”

5. Robert Hooke Observed plant stems, wood, and cork (1600’s)
Pg 170
Observed plant stems, wood, and cork (1600’s)
Saw all the tiny chambers and called them CELLS
What cell part did Hooke observe?
Cell Wall

6. Pg 169

7. Robert Brown (1833)
Observed that cells had a dark structure within plant cells
Brown observed the nucleus

8. Matthias Schleiden (1838) Stated that all plants are made of Cells
Pg 171
Stated that all plants are made of Cells
Made many observations of plants around the area

9. Theodor Schwann (1839) Stated that all animals are made of Cells
Pg 171
Stated that all animals are made of Cells
Observed many animal tissues

10. Rudolf Virchow (1855)
Stated that all cells come from pre-existing cells
Cells arise from the division of pre-existing cells

11. The Cell Theory All living things are composed of cells
Cells are the basic unit of structure and function in living things
All cells come from pre-existing cells

12. Exceptions to the Cell Theory
Viruses – are not cellular (cannot reproduce on own)
Mitochondria and chloroplast – each contain genetic material and can reproduce on their own

14. Two Types of Cells Prokaryotes Eukaryotes Pg 173 Membrane Cytoplasm
EUKARYOTIC CELL
PROKARYOTIC CELL
DNA
(no nucleus)
1 µm
Organelles
Nucleus (contains DNA)

15. “So what’s the big diff ?”
Pg 173
Prokaryotes
Eukaryotes
Have NO membrane bound organelles, have Nucleiod region (no true nucleus)
Has membrane bound organelles: Nucleus, mitochondria, golgi, ER, & vesicles
1-10 µm ( meters)
µm (micrometers)
smaller
BIGGER
Structurally simpler
Structurally more complex
Examples:
Bacteria (Eubacteria)
Archaea
Protists Plants
Fungi Animals
Unicellular (one-celled)
can live in colonies
Mostly multicellular (Protists are exception)

17. Prokaryotes
Pg 173

18. Eukaryotes

19. But Both Prokaryotes and Eukaryotes can have:
cell membrane, cell wall, cytoplasm, ribosomes, DNA & RNA
End of Cell Types, Next up: Cell energy

20. Cellular Energy: what powers a cell?
Tip: think of energy as a form of currency (you know…$$$)
You can exchange energy to get work done (just like $$$)
Adenosine triphosphate (ATP)
Pg 203
(don’t try to draw this)

21. ATP
Pg 203
(draw this)
Energy is found in the bonds between phosphorus and is released when we break those bonds

22. ATP = $$$ This energy is used by cells to do:
Pg 203
This energy is used by cells to do:
Chemical work (chem rxns)**
Mechanical work (muscle cells)
Transport Work (active transport)
(draw just this side)
Reactants  Products
Before Rxn
After Rxn

23. Two types of chemical reactions
Endergonic Reaction: reactants require energy to work to products
Reactants + energy  Products
Pg 203

24. Two types of chemical reactions
Exergonic Reaction: reactants will release energy as reaction goes to product
Reactants  Products + Energy

26. But what if we could make the EA less of a pain?
However ALL reactions require an initial input of energy to get started (even exergonic rxns). Without this initial energy the rxn won’t happen.
We call this Activation Energy (EA)
So the EA must always be satisfied for a reaction to occur.
But what if we could make the EA less of a pain?

27. A.A. order  protein’s shape  protein’s function
Enzyme: A protein (chain of amino acids) that lowers the activation energy of reactions. One specific enzyme for one specific rxn. After the reaction, the enzyme is released and is unchanged, so it can be used many times, and can speed up some rxns by more than a billion times
A.A. order  protein’s shape  protein’s function
(sound familiar?)
Exoergonic Rxn
Endergonic Rxn

28. Enzyme & Substrate fit like a lock & key (Shape specific)
pH or temperature can change the active site shape on any enzyme
Active site is where the reactants bind to the enzyme
END

29. Speaking of speedy things