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Computer Information Processing. Computing. Input. Output. Unorganized Data. Organized Data. www.gls.gov.uk/. Computer Programming. Cellular Information Processing. Biological. Input. Output. Unorganized Signals. Cell Function. scienceprofonline.googlepages.com.
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Computer Information Processing Computing Input Output Unorganized Data Organized Data www.gls.gov.uk/ Computer Programming
Cellular Information Processing Biological Input Output Unorganized Signals Cell Function scienceprofonline.googlepages.com Biological Programming
Role of Cell Function in Biology • The cell is the fundamental unit of living things • Everything that that happens in the organism happens at the level of the cell • Biological molecules dictate cell function • To understand cells (biological information processing) must understand biological molecules
Cell Function • Understand Cell Function in Molecular Terms • Begin with a question: • Are your skin cells different from your heart cells? • If so, how? Skin Cells Heart Cells
Central Dogma of Biology Info Info Carrier Functional Product DNA RNA PROTEIN
Making Skin into Heart • Alter gene expression of skin cells to make them pluripotent stem cells • Pluripotent – capable of becoming different kinds of cells • Like embryonic stem cells • Grow under conditions that induce differentiation into heart cells (new gene expression) • Accomplished by two groups in 2007 • One in Japan and one in U.S.
Expression of four genes change skin cells into pluripotent embryonic stem cells Oct3/4, Sox2, Klf4, Myc Making Stem Cells Holm Zaehres and Hans R. Schöler, Cell, Vol 131, 834-835, 30 November 2007
First Observation of Cells • Occurred 150 yrs before cell theory (1670) • Antonie van Leeuwenhoek (animalcules) • Robert Hooke (cells in cork)
Remarkable Variety of Cells • 200 different types in the human body • All cells can be categorized into 2 basic plans • Prokaryotic (before kernel, before nucleus) • Eukaryotic (true kernel, true nucleus)
Nucleus Command center for gene expression • Contains 95% of the cell’s DNA (genes) • Genes are selected for expression • Site of RNA synthesis (transcription) • Produces mRNA • DNA is in a complex called chromatin
Chromatin • DNA-Protein complex (1:1 mass ratio) • Proteins are histones (basic amino acids) • Histones help to pack DNA (146 bp +linker)
Cytosol (Cytoplasm) • Everything that is not an organelle • Much of cellular metabolism occurs in the cytosol • Protein synthesis occurs in the cytosol • Cytosol is highly compartmentalized • Compartments and trafficking is controlled by the cytoskeleton