1. Cells
Inside and Out

2. Cell Theory
English scientist Robert Hooke used a crude microscope to look at a slice of cork.
He saw little boxes that reminded him of the small rooms that monks lived in – Cells

3. Cell Theory
Later the observations of scientists Schleiden, Schwann and Virchow led to what we call the Cell Theory:
All living things are composed of one or more cells
Cells are the basic units of structure and function in organisms
All cells arise from existing cells

4. Size Chart
Atom
Molecule
Organelle
Cell
Tissue
Organ
Organ System
Organism
Population
Community
Ecosystem

5. Cell Size
Having many small cells is more efficient than having a few large cells
Small cells have larger surface to volume ratios than large ones
So, substance exchange is faster in small cells than in large.

6. Surface to Volume Ratio Example
Surface area Equation on a cube
L2 X 6
Volume Equation of a cube
L2 X H

7. Magnification Light microscope Magnification Resolution
Visible light passes through object
A Lens magnifies the image
Magnification
Making an image seem larger than what it is
Resolution
What measures the clarity of an object
What limits a particular type of scope

8. Magnification Electron Microscope 100,000 X magnification power
Scanning Electron Microscope (SEM)‏
Allows for better resolutions on the surface of an object
Shows object in 3D
Good for observing living organisms

9. Magnification Electron Microscopes
Transmission Electron Microscope (TEM)‏
Observer to sees through cells
allows the observer to see specimen's internal structure

10. Features Common to All Cells
Cell Membrane
All cells share this outer boundary
This membrane encloses and separates the interior of the cell – the cytoplasm
The cell membrane also regulates what enters and leaves the cell

11. Features Common to All Cells
Cytoplasm (Cyto= cell, -plasm= formative material)‏
Everything between plasma membrane and nucleus or nucleoid region.
Cytoskeleton (Cyto= cell, -skeleton= structural framework)‏
Structure made of microfibers & microtubules within the cytoplasm that suspends the cells structures
Most cells have ribosomes
Cellular Structures on which proteins are made

12. Prokaryotes Bacteria Cells Evolved before eukaryotic cells
Have no nucleus
Evolved before eukaryotic cells
Structures Common to Prokaryotes
Nucleoid region- where the chromosome is
ribosomes- protein synthesis
Cell membrane- “gate keeper”
Cell wall (different than plants)‏- support
Some have capsules outside wall- resistance to antibiotics
Pili- exchange of genetic info
Flagella- movement

13. Prokaryotes

14. Eukaryotes Plant and Animal Cells
Cells are more complex than prokaryotic cells
Much like Prokaryotes Eukaryotic Cells
have a cell wall (plants/protists/fungi)‏
have a plasma membrane
have Cytoplasm
have ribosomes
But within their cytoplasm eukaryotes have
Organelles
Cytosol - fluid in cytoplasm

15. Major Organelles to know
Cytoskeleton- support & protection
Cell membrane- “gate keeper” controls what enters or leaves the cell
Nucleus- holds the chromosomes, directs cell
Endoplasmic Reticulum- transport & protein formation
Golgi Apparatus- packages things
Lysosomes- hold digestive enzymes, “suicide sac”
Vesicles- storage
Mitochondria- “Power house” respiration, ATP energy
Cell Wall- support, protection
Chloroplasts- photosynthesis, make glucose
Central Vacuole- storage, especially of water
Ribosomes- protein making

16. Cytoskeleton Provides interior framework to support cell
Made of network of protein fibers tied to the plasma membrane.

17. Cytoskeleton There are three kinds of cytoskeleton fibers
Microfilaments (or Actin Fibers)‏
Made of protein actin
Works in the shape and movement of a cell
Microtubules
Tiny tubules made up tubulin protein
Highway for transportation of info. from nucleus to parts of the cell
Intermediate Fibers
Rope-like fibers where enzymes and ribosomes anchor in the cell

18. Cell Membrane
Phospholipid bilayer - barrier separating inside of cell (cytoplasm) from outside
Selectively permeable (penetrable) - controls what enters & leaves cell

19. Proteins Embedded in the Plasma Membrane
** Proteins are macromolecules made of amino acids
Some proteins embed in the plasma membrane
Enzymes
Transport Proteins
Receptor Proteins
Must have both polar & non polar ends to embed in the membrane

20. Nucleus Nucleus and mitochondria contain genes Nucleus consists of:
Envelope
Double membrane
Pores let messages in and out
Chromatin
DNA
Protein
Nucleolus
Produces rRNA
rRNA with proteins makes up ribosomes

21. Nucleus

22. Endoplasmic Reticulum (endo = Inside, plasm = formed material)‏
Major system of internal membranes- move proteins and other stuff through cell
Is a lipid bilayer with embedded proteins
Makes steroids, lipids
Detoxifies chemicals

23. Endoplasmic Reticulum (ER)‏
Rough ER
Has ribosomes embedded so looks “rough”
Processes proteins
Smooth ER
No ribosomes embedded so looks “smooth”
Makes lipids and breaks down toxic chemicals

24. Golgi Apparatus/Lysosomes
Flattened pancake like membrane-bound sacs- the packaging distribution center of the cell

25. Lysosomes/Vesicles Lysosomes (lyso-breaking, -some=body)‏ Vesicles
Small spherical organelles-
hold digestive enzymes
Work with Golgi to produce, package and distribute protiens
Vesicles
Small bubble-like membrane bound sacs
carry material from ER to Golgi and out of cell
Some will become lysosomes

26. Here’s the Protein Flow

27. Mitochondria
Harvests energy from organic compound (sugars) to make ATP
ATP: energy “Money” in the cells
Cellular respiration
Most eukaryote cells contain mitochondria
Double membrane
Big bag stuffed in smaller bag
Folds of inner bag = cristae
Space inside inner bag called matrix
Holds enzymes and DNA
This DNA ONLY inherited from mom

28. Mitochondria

29. Organelles Common to Plants
Plants contain all of the organelles now mentioned plus more
Organelles Only in Plants (not animals)
Cell Wall
Chloroplast
Central Vacuole

30. Cell Wall Surrounds the cell membrane
Made of proteins and carbohydrates
Cellulose - polysaccharide(poly=many, saccharide=sugars) cellulose can NOT be digested by all us, but some can.
Supports and Maintains the shape of a cell
Protects from damage

31. Chloroplasts
Plant cells contain mitochondria to produce the energy “bucks” (ATP), AND they contain chloroplasts to make the glucose the mitochondria “burns” to make the ATP
Chloroplasts use light energy to convert carbon dioxide and water into sugar, oxygen and energy (ATP)‏
Also found in algae and some protozoans.
Chloroplasts
have two membranes
have enzymes & DNA

32. Chloroplasts

33. Central Vacuole Largest organelle in a plant cell
Contains ions (charged atoms), nutrients (macromolecules), and wastes
When full, makes cell rigid which enables the plant to stand upright.

34. Plant Cell

35. The Endosymbiotic Hypothesis
Evolution of the Eukaryotic cell – (with mitochondria and chloroplasts)
Theory: one large prokaryotic cell ingested another which became mitochondria and/or chloroplast in the now eukaryotic cell.

36. Evidence
Both are similar to bacteria in size and shape
Both have a double membrane
Outer from being taken into cell
Inner from original bacterial cell
Contain DNA in loop like bacteria
Contain ribosomes - make proteins
RNA in ribosomes like bacterial cells

37. The Endosymbiotic Theory