EE Lecture 14: What is Life? Flashcards
what does life need to happen
an external source of energy
what is the 2nd Law of thermodynamics
2nd Law of thermodynamics: entropy of closed system increases over time
what is lifeq
a highly ordered state of matter, which expends energy from enviro to maintain order and information, counteracting second law of thermodynamics
which law of thermodynamics does life defy
second law
how does life defy 2nd law of thermodynamics
because it restores entropy as opposed to increasing it
how does order arrive in molecules
self replication - autocatalysis sequences vary in fitness - formation rate supply of energy rich monomers imperfect replication - mutation competition
what is current life based on (chemically)
nucleic acids - info storage&replication
proteins - function but not info
what is Eigen’s paradoz
need info for function to occur, but info meaningless without function
what is an RNA world
can artificially select RNA with catalytic properties eg. polymerase
what is a metabolism world
interacting protein networks with some heritability, self copying
what are main theories of how life originated on earth
- prebiotic soup
- primordial pizza
- fat or water drops
- hydrothermal vents
discuss prebiotic soup as a theory of how life originated on earth
concentrated mixture of precursor molecules in ancient seas zapped by lightning
did reconstructions in lab experiments
discuss primordial pizza as a theory of how life originated on earth
life originated on a surface, catalyst and favours cooperation - clay or iron pyrites
what is cooperation
spontaneous cooperation between nucleic acids and proteins on surface
discuss fat/water drop theory of how life originated on earth
fat or water drops were compartments protecting cooperating molecules from cheats
