1. Structure and Function
CELLS
Structure and Function
Cell = smallest unit of life

2. Two Major Cell Types Cell Type Prokaryotic Eukaryotic Example Bacteria
Protists
Fungi
Plants
Animals

3. Prokaryotic Cell

4. Eukaryotic Cell
(protist, animal)
Eukaryotic Cell

5. Eukaryotic Cell
(plant)
Eukaryotic Cell

6. Differences Between Cell Types
Prokaryotic Cell
Eukaryotic Cell
Single circular chromosome
Multiple linear chromosomes
Chromosome found in a cytoplasmic region called the nucleoid.
Chromosomes found in a membrane-bound nucleus.
No internal membranes
Some infolded plasma membrane
Extensive network of internal membranes

7. Common Components and Cellular Organization
Plasma Membrane
boundary surrounding the cell
Genetic material: DNA
located in a membrane-bound nucleus for eukaryotic cells
Cytoplasm
Semi-fluid matrix containing enzymes and organelles (enzyme = biological catalyst)
Cytoskeleton
network of filaments and tubules in cytoplasm that maintains cell shape, allows movement

8. Features of Prokaryotic Cells
All prokaryotic cells contain
Structure
Function
Plasma Membrane
Regulates flow of substances into and out of cell
Nucleoid
Cytoplasmic region containing genetic material
Cytoplasm
Cytosol: fluid
Ribosomes
Enzymes

9. Features of Prokaryotic Cells
Other possible prokaryotic structures
Structure
Function
Cell Wall
Supports cell
Maintains shape
Capsule
Protects from drying
Protects against white blood cells
Infolded Plasma Membranes
Metabolism
Cell division

10. Features of Prokaryotic Cells
Other possible prokaryotic structures
Structure
Function
Bacterial Flagellum
Movement
Plasmid
Small circular DNA
Replicates independently

11. Applying Your Knowledge
Cell Wall
Flagellum
Capsule
Plasmid
Nucleoid
In bacterial cells
where is the genetic material located?
which one is used for movement?
which one provides structural support for the cell?

12. Functions of Eukaryotic Cell Features
Structure
Function(s)
Plasma Membrane
1. Regulates passage of materials into and out of cell
2. Cell-Cell Recognition

13. Functions of Eukaryotic Cell Features
Structure
Function(s)
Cell Wall
(protists, fungi, plants)
Controls cell shape, protects, supports

14. Functions of Eukaryotic Cell Features
Structure
Function(s)
Nucleus
Carrier of genetic material
DNA + protein = chromatin
2. Governs cell activities
3. Directs cell reproduction
Surrounded by Membrane = nuclear envelope
Contains nucleolus—produces ribosomes which synthesize proteins

15. Functions of Eukaryotic Cell Features
SER
RER
Functions of Eukaryotic Cell Features
Structure
Function(s)
Rough Endoplasmic Reticulum (RER)
Associated ribosomes produce proteins
Prepares proteins for export
Smooth Endoplasmic Reticulum (SER)
Lipid Synthesis
Drug detoxification
Transport of proteins from RER

16. Functions of Eukaryotic Cell Features
Structure
Function(s)
Golgi Apparatus
Collects, modifies, packages and distributes proteins and lipids from ER

17. Functions of Eukaryotic Cell Features
Structure
Function(s)
Lysosome
Contains digestive enzymes to digest food in protists or destroy aging organelles

18. Endomembrane System Rough Endoplasmic Reticulum
Smooth Endoplasmic Reticulum
Vesicle
Golgi Apparatus
Lysosome
Vesicle
Vesicle
Plasma
Membrane

19. Functions of Eukaryotic Cell Features
Structure
Function
Peroxisome
Removes harmful oxidants from cells

20. Functions of Eukaryotic Cell Features
Structure
Function
Mitochondrion
Captures energy from organic molecules, producing ATP

21. Functions of Eukaryotic Cell Features
Structure
Function
Chloroplast (protists, plants)
Photosynthesis: Uses light energy to produce organic molecules

22. Functions of Eukaryotic Cell Features
Structure
Function(s)
Cytoskeleton
Maintains cell shape
Anchors organelles and proteins
Allows for organelle movement and cellular movement in some cell types

23. Functions of Eukaryotic Cell Features
Structure
Function
Centriole
Gives rise to basal bodies that produce cilia or flagella

24. Functions of Eukaryotic Cell Features
Structure
Function(s)
Vacuole
Central vacuole (plants) stores waste, maintains turgidity.
Contractile vacuole (protists) maintains water balance.
Food vacuole (protists) fuses with lysosome for digestion.

25. Functions of Eukaryotic Cell Features
Structure
Function(s)
Cilia and Flagella
Move substances across cell surface in lungs, fallopian tubes
Cell movement in sperm, protists

26. Applying Your Knowledge
Cilium
Rough ER
Golgi apparatus
Smooth ER
Lysosome
Which organelle produces proteins that will be exported from the cell?
Which organelle contains digestive enzymes?
Which site acts as a protein packaging and distribution center?

27. Thought Questions What are similarities for
a. eukaryotic and prokaryotic cells?
b. animal and plant cells?
2. What are differences between

28. Analogy If the cell were a factory the ____________________ would be
(name a cell component)
a _____________________________. (name a part of a factory)

29. Part of Cell Part of Factory Capsule Security Gate Cell Wall
Outer Fence around the factory
Chloroplast
Solar Panel
Cytoskeleton
Moving Belt where items are inspected
Steel Support, Interior Walls
Cilia/Flagella
Conveyor Belt, Elevator/Escalator
Enzyme
Worker; Assemblage Machinery
Golgi Complex
Distribution/Packaging Department
Mailroom
Mitochondrion
Generator, Engine Room, Power Source
Nucleoid
Storage of pre-production material
Nucleus
Supervisor’s Office, Boss
Corporate Office, Central Operations
Plasma Membrane
Loading/Unloading Dock, Inner Wall, Door
Ribosomes
Assembly Line Track
RER
Production Line
SER
Shipping Dock
Vacuole
Storage Area

30. Cellular Interactions
Signal Transduction: passing a signal from the cell surface to the interior
First messenger binds to Cell Surface Receptor
Receptor signals nearby Regulator Protein
Regulator activates nearby enzyme
Enzyme catalyzes formation of Second Messenger
Second Messenger initiates Cellular Response

31. Cellular Interactions
Cell Adhesion: joining of cells controlled by proteins called Cellular Adhesion Molecules (CAMS)
important in
Inflammatory Response
Placenta Formation
Learning and Memory
Lack of cell adhesion is implicated in cancer and arthritis.