Evolution ~Origin 2

Front 1

Organics from space

Back 1

- have discovered amino acids and alkanes in meteorites,
-earth experienced heavy bombardment with meteors and comets early on
-early environment was unfriendly to life and this would have been small amount, also they are the opposite stereoisomer from molecules found in living systems

Front 2

Making condensations favorable, how to drive reactions to the product side

Back 2

-biomolecules are polymers formed through condensation reactions
-because water is a product these reactions are not favorable in the ocean
1. organic condensing agents
2. concentration by evaporation (tide pools)
3. concentration by freezing
4. solid state thermal polymerization
5. surface catalysis on clay or iron sulfide
-clay catalyzes formation fo L-stereoisomers of amino acids which match those found in organism on our planet
-clay catalyzes formation of D-isomers of sugars, as exist on our planet

Front 3

Criteria for early chemical stages of life

Back 3

-components must have plausible routs of prebiotic synthesis -must posses a selective advantage over other polymers or chemicals (genotypic or phenotypic)
-the ability to replicate (transmit information)
-must be capable of change (adaptation)
-both nucleic acids and proteins have some of the above qualities

Front 4

which came first RNA or DNA?

Back 4

evidence suggests RNA -but it was also likely preceded by a more primitive self-replicating chemical system

Front 5

ribozymes

Back 5

discovered in 1980’s
-single stranded structure loops on itself so bases interact by H-bonds
-catalytic
-capacity for information storage and transmission
-capacity to do biological work
-copies have different fitness therefore evolution is possible

Front 6

evidence for RNA world

Back 6

capacity for information storage and transmission and capacity to do biological work ribozymes, RNA’s role in replication and metabolism (ribosomes, tRNA, protein synthesis, ribonucleotide triphosphates (ATP, GTP and other electron transfer molecules), can potentially replicate itself thru redundant base pairing (mutability allows evolution)
-energy currency of modern living systems (ATP, GTP, UTP) are ribonucleotides
-RNA plays huge roles in protein synthesis including ribosomes, mRNA & tRNA
-coenzymes common to all living systems contain ribonucleotide components

Front 7

Origin of organized structures

Back 7

vesicles and microspheres have both been shown capable of forming under prebiotic conditions

Front 8

Origin of selection-when does selection arise?

Back 8

-when a population of individuals exists
-when the properties of these individuals are governed by reactions where they absorb and transform material in the environment to their own material
-when individuals differ in the efficiency with which the processes take place
-when the availability of material and energy is limited so that not all types of individuals can form, nor can all types of formed individuals survive...