Lecture 3: The Origin of Life-by Denis
January 1- (4,600 mya) So, what is life?
• Mars Curiosity Life developed early
• Stromatolites (3.5 billion years ago)
• life evolved
• Cells made of lipids
• Genetic system based on DNAaeaa
• DNA to RNA to Protein transfer of information
• Common system of protein assembly
• Glucose What came before LUCA?
Bacteria Archaea Prokaryotes don’t exist!
a Stages of prebiotic evolution
So what do you need?
Geophysical What was the composition of
Stage the Earth and atmosphere?
Chemical How could the building blocks
Stage of life be synthesized?
How did the building blocks
Stage organize into living cells? Australopithecus afarensis Chemical stage
• Can one make organic molecules from inorganic
• Miller-Urey experiment
molecules? Miller Urey Experiment
• Unanswered questions...
– Development of polymers (he made
– Chirality (“handedness”)-e.g; 2 hands
can’t overlap Chirality
• Two enantomers (optical isomers)
D - alanine
L - alanine