Computer Information Processing
Input Output
Unorganized Data Organized Data
Computing
www.gls.gov.uk/
Computer Programming
Cellular Information Processing
Biological
scienceprofonline.googlepages.com
Input
Unorganized Signals
Output
Cell Function
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
DNA RNA PROTEINInfo Info Carrier Functional Product
What kind of cells are these?
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.
Making Stem Cells
Expression of four genes change skin cells into pluripotent embryonic stem cells Oct3/4, Sox2, Klf4, Myc
Holm Zaehres and Hans R. Schöler, Cell, Vol 131, 834-835, 30 November 2007
Once Skin and Now Heart
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)
Eukaryotic Cell (animal)
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
Nucleus Structure
Chromatin
DNA-Protein complex (1:1 mass ratio)Proteins are histones (basic amino acids)Histones help to pack DNA (146 bp +linker)
ER and Golgi 10.11
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
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