Download - Introduction to Cell Biology and Stem Cells
AP Biology 2008-2009
Cells
Life’s Lego Blocks
Regents Biology
What’s Biology?
Regents Biology
How do you know
…if something’s alive?
Regents Biology
The Functions of Life Nutrition
Obtain molecules needed for ATP production Glucose, O2, CO2
Excretion Rid of waste
Metabolism ATP production Synthesis of
proteins, carbohydrates, fats, nucleic acids
Response React to stimuli
Homeostasis Maintaining a constant internal environment
Growth Reproduction
Asexual or sexual
ATP
Regents Biology
bacteriacells
bacteriacellsTypes of cells
animal cellsanimal cells plant cellsplant cells
Prokaryote- no organelles
Eukaryotes- organelles
Regents Biology
The Cell Theory 1665 Robert Hooke and his microscope
“I have found that the pith of the Elder or almost any other tree, the inner pith of Cany hollow stems of other vegetables: as Fennel, Carrets Daucus, Bur-docks, Teasles, Fearn, and some kind of Reeds, have much the same structure.”
Regents Biology
Many shapes
Shape Function
Regents Biology
Many sizes
Bacterial cell
Animal cell
micron = micrometer = 1/1,000,000 meter diameter of human hair = ~20 microns
most bacteria 1-10 microns
eukaryotic cells 10-100 microns
Regents Biology
The Cell Theory A cell is the smallest unit of life
Cells come from existing cells
All living organisms are composed of cells
Multicellular Unicellular
Regents Biology
Testing the Cell theory Striated muscle cells
30mm long (average human cell 0.03mm)
Fungi Hyphae and septa
Algae Acetabularia
One nucleus 100mm long
Regents Biology
Multicellular organisms
• Animals• Plants• Some algae• Some fungi
Regents Biology
Unicellular organisms• Bacteria (prokaryotes)• Archaea (prokaryotes)• Protozoa (eukaryotes)• Some algae (eukaryotes)• Some fungi (eukaryotes)• Perform all functions of life!
Regents Biology
Unicellular organisms perform ALL THE FUNCTIONS OF LIFE!
Nutrition Obtain molecules needed for ATP production Glucose, O2, CO2
Excretion Rid of waste
Metabolism ATP production Synthesis of
proteins, carbohydrates, fats, nucleic acids
Response React to stimuli
Homeostasis Maintaining a constant internal environment
Growth Reproduction
Regents Biology
Unicellular organisms Paramecium (heterotroph)
Eats other small protozoa
Chlorella (autotroph) photosynthesis
Regents Biology
Unicellular organisms Paramecium Chlorella
Regents Biology
Unicellular organisms Sometimes live in colonies
Volvox aureus Algae 500+ identical cells inside protein coat
Regents Biology
Multicellular organisms
Cells interact as a cooperative group
Emergent Properties
Regents Biology
Complex Multicellular organisms Cells → Tissues → Organs → Bodies
bodies are made up of cells cells do all the work of life!
Am I Pen or a collection of
cells?
Emergent propertie
s
Regents Biology
Specialization 220 cell types in the human body
Contain all ~25,000 genes Only express the few it needs Differentiation = turning some genes on
some off Alxel and Buck (2004): Differentiation in
olfactory receptors
Regents Biology
Differentiation of Germ Layers
• Triploblast• Diploblast
Regents Biology
Germ Layers
Regents Biology
Stem Cells Pluripotent
Regents Biology
Stem Cells Early stages of embryonic development
Potential to produce copious quantities
Potentially use in Therapeutic (regenerative medicine) Non-therapeutic (meat) Research
Small number remain in adult Bone marrow, skin, liver
Regents Biology
Sources of stem cellsEmbryonic Umbilical cord Adult
Unlimited growth potential
Easily obtained and stored
Difficult to obtain
Unlimited differentiation Fully compatible with other tissues of the body
Less growth potential than embryonic stem cells
Likely genetically different from adult patient
Limited capacity to differentiate
Limited capacity to differentiate
Removal kills embryo Limited number of cells available
Fully compatible with adult tissues
Less chance of accumulation of mutations
No effect on child due to extraction
No effect on adult due to extraction
Regents Biology
Stem Cells 1. Stargardt’s Muscular Distrophy
ABCA4 gene mutation Malfunction in transport membrane in
retina Loss of vision
Therapeutic use of stem cells? How could they help? What are risks?
Regents Biology
Stem Cells Leukemia
Cancer of white blood cells Large production of WBC in marrow
Normal WBCC: 4,000~11,000 per mm3
Leukemia WBCC: >30,000 per mm3
Treatment Destroy cancer-producing cells
Chemotherapy, radiation
Store and reintroduce stem cells into bone marrow
Regents Biology
Ethical Implications
Benefits
Potential for curing diseases Stargart’s Disease Leukemia
Considerations
(esp. Embryonic Stem cells) When does life begin? IVF
Many embryos are not used
Regents Biology
What do you think?Case Study
Jim and the Forgotten Embryos