This document discusses the cellular basis of life, including the composition and structures of cells. It describes the major chemical elements found in cells like carbon, oxygen, hydrogen and nitrogen. It then discusses the structures of the generalized animal cell including the nucleus which houses DNA, the plasma membrane which encloses the cell, and the cytoplasm where most cellular activities take place. Various cellular organelles like mitochondria, ribosomes, the endoplasmic reticulum, and lysosomes are also described based on their functions. The document concludes by noting the over 200 different cell types that make up the human body and examples of some key cell types.

1. The Cellular Basis of Life
Chapter 3
Part 1

2. The Magic School Bus:
Goes Cellular

3. Introduction to Cell Biology
– Chemical in the cells
• Major Elements
– Carbon (C)
– Oxygen (O)
– Hydrogen (H)
– Nitrogen (N)
“Biology is the search for chemistry that works.”

4. Trace Elements
– Calcium (Ca)- blood
clotting
– Iron (Fe)- hemoglobin
– Iodine (I)- controls
metabolism
– Electrolytes- carry an
electrical charge
http://www.ehu.es/biomoleculas/PROT/hemoglobin.jpg

5. Iodine Deficiency
http://www.mja.com.au/public/issues/178_01_060103/li10764_fm-4.jpg
http://carondelet.net/PeriodicTable/I/iodized%20salt.jpg

6. Water in the Cell
– Cells are 60% water
– Interstitial fluid
• Dilute, saltwater around cells
• Site of all exchanges between cells and blood

7. Variations in Cells- Length
http://www.acticare.com/conditions/images/sciatic_nerve2.jpg
http://www.iss.k12.nc.us/schools/shs/jmcCartney/redcell.jpg
2 micrometers
Over 1 meter

8. Variations in Cells- Shape
• Red Blood Cells- disk
shaped
• Nerve Cells- spindle
shaped
• Smooth Muscle Cells-
Threadlike
• Epithelial Cells-
Cubes
http://www.idahoptv.org/dialogue4kids/season3/brain/Images/neuronlabels.gif

9. Variations in Cells- Function
• Over 200 cell types found in the body

10. The Generalized Cell
– Demonstrates the basic
parts that all cells
contain
– Has three parts
• Nucleus
• Plasma Membrane
• Cytoplasm
http://www.cse.ucsc.edu/~sugnet/documentation/biology_starter/images/animal_cell_580_915.jpg

11. The Nucleus
– Nuclear Envelope
• The membrane of the
Nucleus
– Nucleoli
• Where ribosomes are
assembled
• Round, dark staining
bodies
– Chromatin
• DNA combined with
protein
• When the cell divides the
DNA condenses into
chromosomes

12. Plasma Membrane
• Fragile, transparent barrier that contains the cell
contents and separates them from the surrounding
environment
– Lipid Bilayer
– Proteins
– Glycoproteins

13. Lipid Bilayer
• Phospholipid
• Cholesterol
http://www.biology.arizona.edu/chh/problem_sets/kidneysmetals/graphics/bilayer.gif

14. Proteins
• scatter the surface of the plasma membrane
– Receptors for hormones
– Transport Proteins
http://www.nirgal.net/graphics/coli_protein.jpg
http://www.science.org.au/nobel/1996/images/picture-0.jpg

15. Glycoproteins
• Blood type
• Cell-cell
communication
http://www.funhousefilms.com/glycolip.jpg

16. Specializations
• Microvilli
– finger-like projections to
increase cell’s surface area

17. Specializations
• Tight Junctions
– impermeable junctions that
bind cells together into leak-
proof sheets
• Desmosomes
– Anchoring junctions that
prevent cells subjected to
mechanical stress from falling
apart
• Gap Junctions
– Allow communication
– Connexons- hollow cylinders
composed of proteins that span
the entire width of the abutting
membrane

18. Cytoplasm
– Cellular material outside the nucleus and inside
the plama membrane
– Site of most cellular activities (factory)
– Three Elements
• Cytosol- semitransparent fluid
• Organelles- parts that have specific functions
• Inclusions- non-functioning units

19. Cytoplasmic Organelles

20. Cytoplasmic Organelles
• Mitochondria
– Enzymes break down
food and capture the
energy in ATP
molecules
– Liver and muscle
cells have hundreds
of mitochondria
http://www.cbs.dtu.dk/staff/dave/roanoke/mitochon.gif

21. Cytoplasmic Organelles
• Ribosomes
– Made of proteins and rRNA
– Site of protein synthesis
• Endoplasmic Reticulum
– System of fluid-filled
cisterns that coil and twist
through the cytoplasm
– Rough ER- studded with
ribosomes
– Smooth ER- cholesterol
synthesis and breakdown,
fat metabolism, and
detoxification http://dragon.seowon.ac.kr/~bioedu/bio/ohp/t-021.jpg

22. Cytoplasmic Organelles
– Golgi Apparatus
– stack of flattened sacs
– Modifies and packages proteins

23. Cytoplasmic Organelles
– Lysosomes
– Sacs of powerful
digestive enzymes
– Digests wornout cell
structures and most
foreign substances
– Peroxisomes
– Sacs that contain
powerful oxidase
enzymes
– Detoxify poisonous
substances and
disarm free radicals
http://www.cs.utexas.edu/~s2s/latest/cell1/src/tutorial/lysosome.html

24. Cytoplasmic Organelles
• Cytoskeleton
– Provides cells framework
and cells shape
– Microfilaments- cell
motility and makes changes
in cell shape
– Intermediate Filaments-
form desmosomes and
resists pulling forces
– Microtubule- overall shape
of a cell and important in
cell shape

25. Cytoplasmic Organelles
– Centrioles
– Rod-shaped bodies that are at right angles
– Other Cell Structures
– Cilia- whiplike cellular extensions that move substances
along the cell surface
– Flagella- Longer projection that moves the cell

26. Cell Diversity
• Trillions of cells in the body, 200 different cell types

27. Cells that connect body parts
• Fibroblast- secretes cable-like fibers
• Erythrocyte (red blood cell)- carries oxygen in the
blood stream

28. Cells that cover and line body
organs
– Epithelial cell- pack together into sheets

29. Cells that move organs and body
parts
• Skeletal and Smooth Muscle cells- contract in order
to move bones or internal organs

30. Cell that stores nutrients
• Fat cell- stores a lipid droplet

31. Cell that fights disease
• Macrophage- digest infectious microorganisms

32. Cell that gathers information and
controls body functions
• Nerve cell (neuron)- send electrical signals

33. Cells of reproduction
• Oocyte- female egg cell
• Sperm- male cell with flagellum