1. Chapter 3 Cells and Tissues

2. Cells and Tissues Cells are the building blocks of all living things
Tissues are groups of cells that are similar in structure and function

3. Anatomy of the Cell Life – It’s all about the cell!
Cells are not all the same but all cells share general structures and some functions
Metabolism
Reproduction
Irritability
Mobility
Ability to Grow
Cells are organized into three main regions
Nucleus
Cytoplasm
Plasma membrane
Figure 3.1a

4. The Nucleus Control center of the cell Three regions
Contains genetic material (DNA)
Three regions
Nuclear membrane
Nucleolus
Chromatin
Figure 3.1b

5. Nuclear Membrane Barrier of nucleus
Contain nuclear pores that allow for exchange of material with the rest of the cell

6. Nucleolus Site of ribosome production
Ribosomes then migrate to the cytoplasm through nuclear pores

7. Chromatin Composed of DNA and protein Scattered throughout the nucleus
Chromatin condenses to form chromosomes when the cell divides

8. Plasma Membrane Barrier for cell contents Double phospholipid layer
Hydrophilic heads
Hydrophobic tails
Other materials in plasma membrane
Protein
Cholesterol
Glycoproteins

9. Plasma Membrane
Figure 3.2

10. Plasma Membrane Specializations
Microvilli
Finger-like projections that increase surface area for absorption
Figure 3.3

11. Plasma Membrane Specializations
Membrane junctions
Tight junctions
Bind cells together
Desmosomes
Anchoring junctions
Gap junctions
Allow chemicals to pass for communication
Figure 3.3

12. Cytoplasm Material outside the nucleus and inside the plasma membrane
Cytosol
Fluid that suspends other elements
Organelles
Little organs
Metabolic machinery of the cell

13. Cytoplasmic Organelles
Figure 3.4

14. Cytoplasmic Organelles
Ribosomes
Site of protein synthesis
Found at two locations
Free in the cytoplasm
Attached to rough endoplasmic reticulum

15. Cytoplasmic Organelles
Endoplasmic reticulum (ER)
Assembles materials for inside and outside the cell
Two types
Rough ER (with ribosomes)
Smooth ER (without ribosomes)

16. Cytoplasmic Organelles
Rough Endoplasmic Reticulum
Assembles proteins made by the ribosomes to be exported out of the cell
Usually found close to the nucleus
Smooth Endoplasmic Reticulum
No ribosomes on the surface
Makes lipids for cell membrane
Detoxification of drugs

17. Cytoplasmic Organelles
Golgi apparatus
Modify, sort and package proteins from the rough ER to be secreted out of the cell or stored in the cell
“Customization shop” – the finishing touches

18. Cytoplasmic Organelles
Figure 3.5

19. Cytoplasmic Organelles
Lysosomes
Filled with enzymes
Digestion or breakdown of lipids, carbohydrates, and proteins into small molecules that the cell can use
“The cleaners”
Peroxisomes
Membranous sacs of oxidase enzymes
Detoxify harmful substances
Break down free radicals (highly reactive chemicals)

20. Cytoplasmic Organelles
Mitochondria
“Powerhouses” of the cell
Convert energy stored in food to chemical compounds the cell can use (ATP)

21. Cytoplasmic Organelles
Cytoskeleton
Bones and muscles of the cell
Network of protein structures that extend throughout the cytoplasm
Provides the cell with an internal framework

22. Cellular Projections Not found in all cells Used for movement
Cilia moves materials across the cell surface
Flagellum propels the cell

23. Cell Diversity
Figure 3.7; 1, 2

24. Cell Diversity
Figure 3.7; 3

25. Cell Diversity
Figure 3.7; 4, 5

26. Cell Diversity
Figure 3.7; 6, 7