1. Cell Biology
Part 2

2. Network of protein fibers and in the cytoplasm.
Cytoskeleton
Network of protein fibers and in the cytoplasm.

3. Functions Cell structure and shape. Cell movement.
Cell division - helps build cell walls and move the chromosomes apart.

5. Components of the Cytoskeleton Organized in deceasing diameter
Microtubules
Microfilaments
Intermediate Filaments

6. Microtubules
Structure - small hollow tubes made of the protein “tubulin”.
Size - 25 nm outer diameter with a 15 nm inner diameter. Can be 200 nm to 25 mm in length.

7. Microtubules
Found in the “spindle” apparatus (during cell division), cilia, flagella, basal bodies and centrioles.

8. Functions
Maintenance of cell shape.
Hold organelles in place.

9. Microfilaments 5 to 7 nm in diameter.
Structure – made up of the protein “actin”

10. Functions Muscle contractions. Cytoplasmic streaming.
Pseudopodia (amoeboid movement) found in amoebae and phagocytes (white blood cells).
Cleavage furrow formation.
Maintenance and changes in cell shape.

13. Microfilaments are stained green.

14. Cilia and Flagella Classified by their lengths and numbers
Cilia - short, but numerous.
Flagella - long, but few.
Function - to move cells or to sweep materials past a cell.

16. Cilia and Flagella
Structure arrangement of microtubules, covered by a plasma membrane
(different in bacteria)
Made of contractile proteins
Uses ATP

18. Centrioles and Basal Bodies
act as “microtubule
organizing centers”
or MTOC’s

19. Centrioles Usually one pair per cell, located close to the nucleus.
Found in animal cells only.
9 sets of triplet microtubules.
Help in cell division.

20. Basal Bodies Same structure as a centriole.
Found at the base of the cilia and flagella.

21. Plant Cells

22. Plant Cell

23. Cell Wall Nonliving jacket that surrounds some cells. Found in: Plants
Prokaryotes
Fungi
Some Protists

24. Plant Cell Walls All plant cells have a Primary Cell Wall.
Some cells will develop a Secondary Cell Wall.

25. Cell Walls Plant cell walls are made of cellulose
( a polysaccharide made of b-glucose).
Fungi cell walls are made of chitin (a polysaccharide)
Function as the cell's exoskeleton for support and protection.

26. Middle Lamella
Thin layer rich in pectin (used to make jelly) found between adjacent plant cells.
Glues cells together.

28. Vacuoles and Vesicles Fluid-filled, membrane-bound bodies
5 Types of Vacuoles and Vesicles
Transport vesicles
Food vacuoles
Storage vacuoles
Central vacuoles
Contractile vacuoles

29. The function of the vacuole depends on the organism.
In Protists
(single-cell organisms)
“Food” vacuoles store newly ingested food until the lysosomes can digest it.
“Contractile” vacuoles pump out excess water.

30. Contractile Vacuole
Contractile Vacuole
Food Vacuoles

31. Central Water Vacuole
Large single vacuole when mature making up to 90% of the cell's volume.

32. Function of Central Water Vacuole
Water regulation.
Storage of ions.
Storage of hydrophilic pigments. (e.g. red and blues in flower petals).

34. Other vacuoles and vesicles
Storage vacuoles in plants store starch, pigments and toxic substances (such as nicotine)
Transport vesicles move materials from one organelle to another, or from organelle to the plasma membrane. (“exocytic vesicles” move materials to the plasma membrane for export, “endocytic vesicles” transport materials from outside the cell to the plasma membrane to be imported)

35. Chloroplasts Contain DNA. Can reproduce themselves.
Often contain starch.
May have been independent cells at one time.

36. Function of Chloroplasts
Photosynthesis - chloroplasts use of light energy to make food. (sugars)
Contain the green pigment chlorophyll.

37. Chloroplasts

38. Enzymes in a crystal

39. Chromoplasts store plant pigments such as chlorophyll, carotene.
Found in plants only.
Classified (named) by color example: Chloro means green, therefore a chloroplast is a green plastid that stores chlorophyll
Leuco means white, therefore Leucoplasts (AKA Amyloplasts) are white plastids that store starch.

40. Comparing Plant Cells and Animal Cells
Have cell walls, chloroplasts, and central water vacuoles…animal cells do not!!
Animal Cells
Have lysosomes and centrioles…. Plant cells do not!!