1. Cell Biology

2. Cell Theory Cell Theory
All living organisms are made of one or more cells.
Cells are the basic unit and structure of living organisms.
Cells arise only from previously existing cells.

3. Prokaryotes and Eukaryotes
Prokaryotic cells: cell without a nucleus or other organelles
often called prokaryotes
many scientists believe prokaryotes are similar to Earth’s first organisms
Eukaryotic cells: contain a nucleus and other organelles
often called eukaryotes
some unicellular organisms, but mostly make up multicellular organisms

4. Cell Types
Prokaryotic : no nucleus Eukaryotic: has a nucleus

5. Cells are AMAZING!

6. Did you know…… The outermost layer of your skin is “dead”?
Most dust found on surfaces come from shed cells?

7. Different Types of Human Cells
Nerve Cells Muscle Cells

8. Why are they so different?
Cells may vary in appearance depending on their particular function. But, most cells, contain very similar organelles.
Ex. Nerve cells are long and contain many projections. They must carry messages, sometimes over long distances, from one location to the next. Muscle cells, on the other hand, have a ropey appearance due to the fact that they must be strong. Both contain a nucleus and other organelles that help a cell manage cellular processes.

9. Animals vs. Plants
Both are eukaryotes
plant cell animal cell

10. How do plant and animal cells differ?
Plant cells have a cell wall and contain chloroplasts- animal cells lack these structures

12. Cell structure & function

13. Plasma membrane (aka cell membrane)
Function
Surrounds and protects cells
Selectively permeable (allows some things to enter & some things to exit cell)
Maintains cellular homeostasis

14. Plasma membrane
Structure- phospholipid bilayer
fluid mosaic model

15. Plasma membrane Structure of Phospholipid bilayer
Outermost layer and inner most layer are water-loving (hydrophilic)
Middle layer is water-hating (hydrophobic)

16. Plasma membrane Structure of Phospholipid bilayer
Outermost layer and inner most layer (heads) are water-loving (hydrophilic)
Middle layer (tails) is water-hating (hydrophobic)

18. Plasma membrane Function Proteins
Transport proteins aid in movement of materials that cannot pass through the plasma membrane
Other proteins help cells identify each other and protect them from foreign materials
Plasma membrane protects the cell in a way that it allows some things to pass through the cell that should be there and does not allow foreign materials to enter the cell. The membrane also keeps things inside of the cell that need to be there.

19. Plasma membrane Function Cholesterol
Helps the cell membrane hold its form
THUS, WE DO NEED “GOOD CHOLESTEROL!”

20. Cell Wall Found in plant cells, fungi, and most bacteria
Plant cell wall is made of cellulose

21. Cell wall Function Provides added protection and structure
Is porous and allows any molecule that is not too big to pass (is not selectively permeable)

22. Cytoplasm
Clear gelatinous fluid in which organelles and other cell parts are held & protected
Chemical reactions occur here.

23. Nucleus the “brains” of the cell
contains an organism’s genetic code (DNA)
controls the function of other organelles

24. Nucleus
surrounded by a double phospholipid bilayer with pores called the nuclear envelope

25. Nucleolus
Found within the nucleus
Produces and contains ribosomes

26. Ribosomes Site of protein synthesis (made) Will leave
the nucleus through
nuclear pores
to produce proteins

27. Ribosomes
Free ribosomes produce proteins that perform functions within the cytoplasm
Ribosomes that attach to the endoplasmic reticulum produce proteins that are transported to other organelles or released from the cell

28. Endoplasmic Reticulum
Series of folded membranes located within the cytoplasm
Site for chemical reactions within the cell

29. Rough ER ER with ribosomes attached
Site for protein synthesis and storage

30. Smooth ER Has no attached ribosomes
Site of lipid production and storage

31. Golgi Apparatus/ Golgi Bodies
Series of flat,tubular membranes
Modifies, packages, and sorts proteins for transit

32. Vacuoles/Vesicles Are membrane-bound sacs
may store needed materials (food, enzymes) for the cell
may store waste

33. Vacuoles/Vesicles Are larger in plant cells than animal cells
Responsible for storage of water in plant cells

34. Lysosomes Are membrane-bound organelles Contain digestive enzymes
Digest worn out cell parts, food, waste, bacteria etc.

35. Mitochondrion (Mitochondria is plural)
Structure
Outer membrane
Surrounds the organelle
Inner membrane
Many folds that increase the surface area thereby increasing efficiency of the organelle

36. Mitochondrion “power house” of the cell
Releases energy that is stored in food
This process is called cellular respiration
Formula: 6O2+ C6H12O6  6CO2 + 6H2O + energy (glucose)

37. Chloroplasts Structure Contains a green pigment called chlorophyll
Surrounded by an outer and inner membrane
Contains membrane-bound sacs called thylakoids
Thylakoids are arranged in stacks called grana
Grana are suspended in a fluid called stroma

38. Chloroplasts Found in organisms that undergo photosynthesis
Plants and algae

39. Photosynthesis
All energy extracted from the food you eat originated from photosynthesis
Formula: 6CO2 + 6H2O + sunlight  C6H12O6 + 6O2

41. Cytoskeleton “framework” of the cell
functions as anchor for organelles
Microtubules
Hollow tubes made of protein that provide support, permit movement, and play a role in cell division
microfilaments
Long protein fibers that permit movement and contraction of cells

42. Cilia Provide mobility short hair-like structures
Aid in movement of unicellular organisms
Help move particles along cell surfaces

43. Flagella
Long whip-like structure
Help unicellular organisms move