1. The Cell

2. First view of cells: Robert Hooke

3. Antony Van Leeuwenhook
One of the fathers of microbiology
Built light microscopes
Discovered bacteria, unicellular protists, and more

4. Cell Theory All living things are made of cells
Smallest living organism is a cell
All cells arise from preexisting cells
(no spontaneous generation)
Formed by Schleiden, Schwann, and Virchow

5. Cytology and Histology
Cytology: The study of CELLS!
Histology: The study of TISSUES!

6. Electron (scanning and transmission) Light (compound and dissection)
Microscopes
Electron (scanning and transmission)
Light (compound and dissection)
Confocal
Electron Tomography

7. Microscopes
Light microscope- resolves to about .2 μm magnification
Electron microscope- resolves to about .2 nm
Scanning (SEM)-cell surfaces
Transmission(TEM)-Internal contents
Newer STM, scanning tunneling, enables 3-D images and can be used w/ living)

8. Cell Size

9. Why are cells so small? What’s keeping them from being larger?
Cells must divide when volume exceeds surface area to keep Surface Area to Volume Ratio high.
Why? video

10. Characteristics of All Cells
An outer membrane
Cytoplasm (or cytosol) –thick fluid
DNA
Organelles (“little organs”)

11. Cell Types
Prokaryotic Eukaryotic

12. Prokaryotic Cells First cell type on earth bacteria
No nucleus or membrane-bound organelles
DNA in nucleoid region
Have cell membrane and cell wall
may have a capsule and pili

13. Eukaryotic Cells: protistas, fungi, animals, plants
PLANT CELL
PROTISTAS
(UNICELLULAR
EUKARYOTES)
ANIMAL CELL
FUNGI CELL

14. Organelles Cellular “organs”
Membrane-organelles (Golgi, RER, nucleus…)
Non-membrane – organelles (ribosomes)
Bacteria-like organelles (chloroplast, mitochondria)

15. Bacteria-Like Organelles
Derived from symbiotic bacteria
Mitochondria, chloroplasts
Endosymbiotic theory
Evolution of modern cells from cells & symbiotic bacteria

16. Representative Animal Cell

17. Representative Plant Cell

18. Meet the Organelles

19. Cytoplasm Viscous fluid contains organelles components Fluid = cytosol
filaments & fibers
Fluid = cytosol
Storage substances

20. Nucleus
Control center of the cell
Surrounded by nuclear membrane (Double membrane w pores)
Contains
DNA
Nucleolus

21. Nucleolus Dark regions within the nucleus produces ribosomes
In animal & plant cells

22. Ribosomes
“protein factories”: site of protein synthesis
Made of rRNA and protein
attached to ER or in cytosol

23. Endoplasmic Reticulum
Membranous maze connected to nuclear envelope
Rough ER – Covered in ribosomes
Makes proteins
Smooth ER – no ribosomes
Lipid synthesis
Detoxifies harmful substances (Cells in liver have a lot of smooth ER)

24. Golgi Apparatus
packaging and shipping of proteins and lipids
Enzymes here attach carbohydrates and lipids to proteins
After the ER makes the proteins, they move into the Golgi Apparatus where they are modified
From the Golgi Apparatus , modified proteins are moved to their destinations

26. Contain digestive enzymes Functions Aid in cell renewal
Lysosomes
Contain digestive enzymes
Functions
Aid in cell renewal
Break down old cell parts
Digests invaders

27. Vacuoles
Membrane bound sacs
Temporary storage areas for food water, enzymes and waste
Special types
Contractile: pumps out excess water in single celled water organisms (protists, protozoans)
Central: large vacuole found in plants used for water storage

28. Site of Cellular Respiration: releases energy from food (ATP)
Mitochondria
Site of Cellular Respiration:
releases energy from food (ATP)
6O2 + C6H12O6  6CO2 + 6H20 +Energy

29. Site of photosynthesis Found in autotrophic cells Double membrane
Chloroplasts
Site of photosynthesis
Found in autotrophic cells
Double membrane
Light energy + 6H2O + 6CO  C6H12O6 + 6O2

30. Centrioles
microtubules
involved in cell division
Animal cells only

31. Peroxisomes Similar to lysosomes (contains enzymes)
Generation and degradation of H2O2 (hydrogen peroxide) to protect cell from it’s toxic effects

32. Cytoskeleton Filaments & fibers Made of 3 fiber types Microfilaments
Microtubules
Intermediate filaments
3 functions:
mechanical support
anchor organelles
help move substances

33. Cilia & Flagella
Provide motility
Cilia
Short
Used to move substances outside human cells
Flagella
Whip-like extensions
Found on sperm cells
Basal bodies like centrioles

34. Cell Wall
Outside the cell membrane
Found in all cells except animal cells
Made from carbohydrates
Cellulose – plants
Chitin – fungi
Peptidoglycan – bacteria
Provides support, protection and excessive uptake

35. Cell Membrane
Thin flexible barrier around the cell
Selectively permeable
Made of:
phospholipid bilayer / proteins / carbohydrate chains /cholesterol

36. CELL MEMBRANE

37. Membrane: Phospholipids
Polar (‘Phospho’)
Hydrophilic heads- face outside
Polar heads interact with water and face toward the water; nonpolar tails are between the polar heads and face away from water
Nonpolar (‘lipids’)
Hydrophobic tails- face inside
*Fluid mosaic model –
describes the fluid nature
of the lipid bilayer with
proteins

38. Membrane Proteins
1. Channels or transporters
Move molecules in one direction (these are like the open doors)
2. Receptors
Recognize certain chemicals

39. Membrane Proteins
3. Glycoproteins
Identify cell type (they are like ID tags for cells to ‘recognize each other)
4. Enzymes
Catalyze production of substances

40. Plant cells: Plasmodesmata-
Cell Junctions
Plant cells: Plasmodesmata-
junctions between plant cells walls

42. Review of Eukaryotic Cells

43. Review of Eukaryotic Cells