1. The Cell
Cell Introduction

2. Cells are the basic unit of living organisms.
A Whole New World
Microscopes enabled scientists to view and study cells.
Cells are the basic unit of living organisms.

3. Scientists and Discoveries
Anton van Leeuwenhoek first discovered cells using a simple light microscope.
Van Leeuwenhoek Biography

4. Scientists and Discoveries
Robert Hooke used the Compound Light Microscope to study cork, the dead cells of oak bark. He observed small geometric shapes and named them cells.
Other scientists extended Hooke’s observations and drew important conclusions.
All plants and animals are made up of cells.
These conclusions led to the creation of the Cell Theory.

5. The Cell Theory 1. All organisms are composed of one or more cells.
2. The cell is the basic unit of structure and function of organisms.
3. All cells come from preexisting cells.
Before the cell theory, no one knew how cells were formed, where they came from, or what determined the type of cell they became. The cell theory states that a cell divides to form two identical cells.
TED-Ed Origin of Cell Theory

6. Exceptions to the Cell Theory
Viruses are not cells. Therefore, viruses are not living. They require a host cell to reproduce.
2. Certain cell organelles behave like cells. Mitochondria and chloroplasts have their own DNA and can reproduce under certain conditions.
3. If all cells come from pre-existing cells, where did the first cell come from?
-Endosymbiotic Theory – Several key organelles of eukaryotes (mitochondria and chloroplasts) originated as a symbiosis between separate single-celled organisms.

7. Hierarchy of Organization in Living Organisms
Organelle Cells Tissue Organ Organ System Organism

8. Membrane-Bound Organelles
Types of Cells
Type of Cell
Nucleus Present
Membrane-Bound Organelles
Examples
Prokaryotic No
Most unicellular organisms
Ex: Bacteria
Eukaryotic
Yes
Most multicellular organisms
-Ex: Plants & Animals
Some unicellular organisms
-Ex: Amoeba, Some Algae

10. Organelle = means “little organ”
Organelles
Cell Organelle Review Video
Organelle = means “little organ”
Functioning unit within a cell.
Helps the cell to function (do its job)
(different cells have different roles/jobs)
Voyage inside a Cell
Inner Life of a Cell
Cell Organelles

11. Cell Organelles in Eukaryotic Cells

12. The Plasma Membrane
Flexible boundary between the cell and its environment.
Controls the transport of nutrients into and out of the cells.
Maintains cell homeostasis

13. Cytoskeleton Cytoplasm
A network of filaments and tubules that extend from the nucleus to the plasma membrane and give structure to the cell.
Cytoplasm
Clear, jelly-like fluid inside a
cell where organelles are
suspended.

14. Endoplasmic Reticulum
Series of highly folded membranes in the cytoplasm where many chemical reactions take place.
2 types of ER:
Rough ER – Surface covered with ribosomes
- (protein synthesis occurs here)
Smooth ER – Production and storage of lipids

15. Ribosomes
Site of Protein Synthesis
Free-floating or attached to ER

16. Golgi Apparatus/Golgi Body/Golgi Complex
Flattened stack of tubular membranes that modifies, sorts, and packages products made in the ER into vesicles to be sent to the appropriate location in the cell.

17. Mitochondria Performs Cellular Respiration
C6H12O6 + O2  H2O + CO2 + ATP

18. One large, central vacuole
Vacuoles
Compartment for the temporary storage of food, wastes, and other materials.
Animal
Plant
Many small vacuoles
One large, central vacuole

19. Lysosomes ANIMAL CELLS ONLY Sacs containing digestive enzymes.
Digest worn out organelles, waste, or engulfed viruses/bacteria
Can fuse with vacuoles, release enzymes, and digest contents inside.
ANIMAL CELLS ONLY

20. Centrioles ANIMAL CELLS ONLY
Create spindle fibers to separate chromosomes during cell division.
ANIMAL CELLS ONLY

21. Cilia and Flagella Used for locomotion (movement)
Cilia - hair-like projections
Flagella - long projections
ANIMAL CELLS ONLY
Bronchial Cilia

23. H2O + CO2 + sunlight energy  C6H12O6 + O2
Chloroplast
Performs Photosynthesis
H2O + CO2 + sunlight energy  C6H12O6 + O2
PLANT CELLS ONLY

24. Cell Wall Provides protection and support
Allows plant to stand upright against gravity
PLANT CELLS ONLY