1. Cells and Tissues
Chapter 3

2. Learning Objectives General Anatomy of a cell
Three main regions of the cell and their structures and functions.
Plasma Membrane structure and function
Membrane junctions

3. Cells and Tissues
Carry out all chemical activities needed to sustain life
Cells are the building blocks of all living things
Tissues are groups of cells that are similar in structure and function

4. Anatomy of the Cell Cells are not all the same
All cells share general structures
All cells have three main regions
Nucleus
Cytoplasm
Plasma membrane

5. What are the three things all cells have in common?
Question
What are the three things all cells have in common?

6. The Nucleus Control center of the cell Three regions
Contains genetic material (DNA)
Three regions
Nuclear envelope (membrane)
Nucleolus
Chromatin

7. The Nucleus

8. The Nucleus Nucleoli Nucleus contains one or more nucleoli
Sites of ribosome assembly
Ribosomes migrate into the cytoplasm through nuclear pores

9. The Nucleus Chromatin Composed of DNA and protein
Present when the cell is not dividing
Scattered throughout the nucleus
Condenses to form chromosomes when the cell divides

10. Questions What is the overall function of the nucleus?
What does the Nucleolus do?
What is the chromatin? Where is it found?

11. Plasma Membrane Barrier for cell contents Double phospholipid layer
Hydrophilic heads
Hydrophobic tails
Also contains proteins, cholesterol, and glycoproteins

12. Plasma Membrane

13. Plasma Membrane Specializations
Microvilli
Finger-like projections that increase surface area for absorption

14. Plasma Membrane Specializations
Membrane junctions
Tight junctions
Impermeable junctions
Bind cells together into leakproof sheets
Desmosomes
Anchoring junctions that prevent cells from being pulled apart
Gap junctions
Allow communication between cells

15. Plasma Membrane Specializations

16. Questions What is the structure of the plasma membrane?
What are the three types of junctions in the plasma membrane and how are they different?

17. Cytoplasm
Cytoplasm is the material outside the nucleus and inside the plasma membrane.

18. Cytoplasm Contains three major elements Cytosol Organelles Inclusions
Fluid that suspends other elements
Organelles
Metabolic machinery of the cell
“Little organs” that perform functions for the cell
Inclusions
Chemical substances such as stored nutrients or cell products

19. Questions What is the cytoplasm?
What are the three major elements of the cytoplasm?

20. Cytoplasmic Organelles

21. Organelle/Structure Poster Project
Design a poster that depicts your assigned organelle/structure.
Include on the poster a Brief but accurate description of the function of the organelle/structure.
Poster must include:
Picture (DRAWN not printed out)
Color
Description of the function of the organelle.
Worth 50 points (20 for the picture, 20 for the description and 10 for neatness and creativity).
DUE TOMORROW!