1. Ch 4 (Honors Bio) Ch 3 (Bio)
CELL STRUCTURE AND FUNCTION

2. The Cell The cell is the smallest unit of life
smallest unit that can carry out life processes.

3. Cellular Organization
Section 2 Introduction to Cells
Chapter 4
Cellular Organization

4. Discoveries Leading to The Cell Theory
Robert Hooke – observed cork through a light microscope
Anton Van Leewenhoek – observed LIVING cells.
Matthias Schleiden – 1883 –all plants are made of cells.
Theodor Schwann – 1839 –all animals are made of cells
Rudolph Virchow all cells must come from other cells

5. The Cell Theory all living organisms are made of one or more cells.
cells are the basic units of structure and function
cells come only from pre-existing cells.

6. Two Basic Types of Cells

7. Prokaryotic Cell Do not have a nucleus
Do not have organelles (internal membrane-bound structures)
Most unicellular organisms are prokaryotes.
Bacteria

8. Eukaryotic Cell Cells that do have a nucleus. They do have organelles.
Most multicellular organisms are eukaryotes.
Yeast and algae (unicellular, eukaryotes)
Plant and animal

9. Features Common to Cells:
Cytoplasm – Gel like material that protects, supports and suspends organelles.

10. Common Features cont…. All cells have DNA. (DeoxyriboNucleic Acid)
Chromosomes vs Chromatin

11. Common Features cont….
Cell (plasma) membrane – Semi-permeable- allows some materials in and keeps others out. This helps to maintain cellular homeostasis.
SELECTIVE PERMEABILITY

12. Structure of the Plasma Membrane
Polar phosphate group allows membrane to interact with its environment.
Fatty acid tails create a water-insoluble layer in the middle which is non-polar.
Phospholipid Bilayer -2 layers of phospholipids.
Phospholipid- phosphate head attached to two lipids (fatty acid tails).

13. Cell membrane Structure
Fluid mosaic model-membrane is flexible
Cholesterol-keeps fatty acid tails from sticking together
Transport proteins -allow needed substances to move through the membrane

14. Parts of the Cell
Chapter 4

15. Nucleus “Command center” Surrounded by a nuclear envelope
Contains genetic material:
chromatin
chromosomes

16. Chromatin vs Chromosomes
When the cell is not actively dividing
CHROMOSOMES
When the cell is dividing

17. Nucleolus and Ribosomes
Nucleolus-makes ribosomes
Ribosomes- build proteins
Can be found floating in the cytoplasm or attached to endoplasmic reticulum

18. Endoplasmic Reticulum (ER)
Series of folded membranes allow a large amount of work to be done in a small amount of space
Transportation unit for the cell

19. Rough Endoplasmic Reticulum (RER)
Has Ribosomes attached
Protein synthesis

20. Smooth ER
Produce and store lipids

21. Golgi Apparatus Vesicles
Flattened tubular membranes
Packaging plant
Modify, sort, package, and transport proteins throughout the cell

22. VACUOLES Storage sacs Animal cells have many small vesicles.
Store food, enzymes, waste
Animal cells have many small vesicles.

23. LYSOSOMES Full of digestive enzymes
Digest excess or worn organelles, food particles, viruses, and bacteria
Surrounded by membrane that prevents it from destroying the cell
Can burst causing cell death

24. Mitochondria Chapter 4 Cellular respiration -converts food into energy
Cell “Powerhouse”
Number of mitochondria depends upon the function of the cell
Ex: muscles cells have more mitochondria than fat cells

25. Cytoskeleton
Cytoskeleton – tiny fibers that give structure and support to the cell.
Microfilament- thin and tubular…support the cell membrane.
Microtubule- thick and tubular also branched. Act as “rails” on which materials move through the cell.

26. Cilia and Flagella Aid in movement and feeding
Composed of microtubules
Flagella-long, whip-like projections
Cilia-short, numerous hair-like projections that move in a wavelike motion

27. Centriole
Help with cell reproduction
Only found in animal cells

28. Cell wall Rigid outer covering PLANT CELLS
Located outside the cell membrane
Provides support and protection
Helps produce turgor pressure

29. Plastids – Color pigments of cells
Examples:
Chloroplast – Located in plant cells, some bacteria, and protists.
Capture light energy to produce (and store) food
Contain chlorophyll-green pigment that traps light energy

30. Large Central Vacuole Plant cells
Storage-stores food, enzymes, wastes, etc

31. Animal Cell
Plant Cell

32. Plant cell vs. Animal Cell

33. Plant vs Animal cells Animal Cell vs. Plant cell Animal Cell
DO contain centrioles.
DO NOT contain a cell wall or plastids.
Plant Cell
DO contain a cell wall, plastids, and a large central vacuole.
DO NOT contain centrioles