1. Cell Walls and Membranes

2. Borders are important… 2 types in cells: walls & membranes

3. Cell Wall What it’s for…
Support
Protection

4. What organisms have cell walls?
Found in…
Plants
Fungi
Algae
Bacteria (prokaryotes)

5. What’s the cell wall made of?
Fibers of carbs and proteins made in the cell
In Plant cells: Composed of cellulose
This is what makes wood and paper

6. Cell membranes (also called plasma membranes)…
Surround all cells
Flexible barrier that separates the inside and outside of the cell
Often referred to as a “mosaic”

7. Cell Membrane Has 2 layers
Has openings for substances to enter and leave the cell

8. What is the cell membrane made of?
Looks like a sandwich

9. Made of phosphate molecules
Outside layers
Made of phosphate molecules
Are Polar – mix with water
Hydrophilic (“water-loving”)
Form two layers like two pieces of bread

10. Inside layer Made of lipids (fat) Water resistant
Non polar, don’t mix with water
Hydrophobic (“water-fearing”)

11. Has small “doorways” or openings that are called transport proteins

12. What’s another name for the cell membrane?
Phospholipid Bilayer

15. Drawing of Cell Membrane
Phospholipid sandwich:

16. Function of cell membrane
Selective permeability
Selective = only some things allowed in or out
Permeability= has small holes in it

17. Without selective permeability the cell would have no control of what comes in and out and would die

18. Membrane is a “fluid mosaic”
Fluid = it moves and is flexible

19. Mosaic = proteins, carbs & cholesterol make a pattern on the surface of the membrane

20. Cell membrane’s function
Provides protection
and support
Anchors the
cytoskeleton

21. Phospholipid bilayer Two layers of lipids
Sprinkled with : glycolipids, carbohydrates, cholesterol and Transport Proteins
Flexible yet strong

26. The Wonderful World of Cells

27. Prokaryotic Cells No true nucleus No membrane bound organelles
DNA is small and a ring
Has free ribosomes
Most primitive of life forms, but also the most sucessful!!!

28. Eukaryotic Cells “True” cells Membrane bound nucleus
Membrane bound organelles
Complex organization
Make up all life except Bacteria

29. The Eukaryotic Organelles
In the following slides, you will get the low down on the organelles found in animal and plant cells.
You will be responsible for knowing each organelle, knowing what its job is, and being able to identify it on a diagram!

30. Cell Wall Only in plant, bacteria & fungi cells
Outside of the membrane
Is stiff gives shape and support

31. Cell Wall Rigid Cell Boundary
NOT IN ANIMAL CELLS!
Made of cellulose,chitin, or peptidoglycans
Retains shape and withstands internal and external pressure
Cell wall

32. Nucleus
Brain of the cell
Contains Chromosomes made of DNA

33. Nucleus The “Brain” of the Cell
It directs the manufacture of proteins and other important chemicals
Contains the nucleolus is key in the production of RNA
It is surrounded by a semi-permeable membrane
Chromatin
Nuclear envelope
nucleolus

34. Cytoplasm Clear jelly-like fluid inside the cell
Cell parts float in it

35. Endoplasmic Reticulum *The cell’s internal Transport Highway
A membrane encased transport and manufacture system
Rough ER has ribosomes and manufactures proteins
Smooth ER manufactures lipids for membranes

39. Ribosomes
Small and round
Make Proteins

41. Ribosomes *Protein Assembly Sites
Small 2-part structures made of rRNA
Site of Protein synthesis (building) using blueprint from the DNA
Can be free, or attached to the ER (Endoplasmic Reticulum)

42. Golgi Apparatus
Flat stacks of small containers
Sort and package proteins

44. The Golgi Apparatus *Postal Service of the Cell
Receives unfinished products from the ER
Refines them to final form
Packages them and tags them for proper delivery
Ships them out of the cell

45. Vacuole *The Storage Closet of the Cell
Storage for chemicals made by the cell
Storage of food particles brought into the cell
Water storage
Water level control (Plants and Protists in particular)

47. Lysosome *Clean-up/ Digestive crew
Small organelles filled with enzymes
Digestion of lipids, carbs, and proteins
Breakdown of worn out cell parts
Removal of toxic chemicals

49. Mitochondria Mighty mitochondria! Help the cell change food to energy
Look like sausages

52. Mitochondria *Power Plant of the Cell
Convert chemical energy from food into ATP (Energy for the cell)
Have their own ribosomes
Have their own DNA

53. Choloroplasts
Only in plant cells
Change light energy into food

55. Chloroplasts *Solar Generator Supreme
Convert solar wave energy to the chemical energy of sugar
Have their own ribosomes
Have their own DNA

56. Cytoskeleton
A network of protein filaments that give shape to the cell
Base for movement in cells
An internal monorail system to move things within a cell
Base for the centrioles used in cell division

57. Centrioles Made of microtubules Important during cell division
Located in the cytoplasm near the nucleus

58. Animal vs. Plant cell
You will be required to label a diagram, and identify the differences between plant and animal cells. See p. 192 of your textbook