Origins Of Life I

Questão	Responda
What are the 7 characteristics of life?	1) Composed of cell(s) 2) Levels of organisation 3) Use energy 4) Respond to stimuli 5) Grow 6) Reproduce 7) Adapt to their enviro + maintain homeostasis
What are the 7 chemical characteristics of life?	1) Carbon based 2) Use energy 3) Use oxidative gradients 4) Contain proteins/lipids/carbs 5) Use nucleic acids for heredity 6) Use ATP 7) Have same basic met. pathways
When did the sun ignite?	50 mya solar system creation
When did the LHB occur	4.1/3.8 bya
Effects on Earth	Sterilised earth Shredded early atmosphere Water fell to earth meteorites fell H became abundant Magnetic poles established
What occurred during the Hadean period?	SC life began The LHB
What occurred during the Archaean period?	Oxygen production began via photosynthesis
What evolved during the Proterozoic period? (3)	Eukaryotes evolved Chloroplasts evolved MC organisms evolved
What evidence exists for panspermia?	Diatoms/nanobacteria identified on meteors from Mars
What did the Miller-Urey experiment hope to achieve?	Replicate Early Earth conditions based on the atmosphere of Jupiter see whether life could form from these constituents
What was the Miller-Urey experiment? (4)	1) Use water/NH4/CH3/H2 2) Spark with electricity 3) Condense 4) Collect and analyse products
What were the products?	Simple amino acids formed via formaldehyde
What issues are associated with the primordial soup?	Early rock analysis showed atmosphere was scarce of ammonia, methane, and hydrogen Concentration problem
Conditions in Black Smokers (3)	Acidic high pressure Iron pyrite catalyst
Redox reaction on iron pyrite, releasing H2S	H2S + O2 -> Energy
What is the main flaw of this theory?	Environment was O2 poor and the overall reaction was FLAT.
What improvement was provided as an alternative to this theory?	Gunter Wachtershauser proposed 2H2S + Fe -> FeS2 + 4H+ FeS2 then reacts with CO which is found in black smokers.
What problem still exists with this theory?	Concentration problem Needs to be confined within a space
What is serpentination? (3)	Rock mixes with mantle Gives up sea water Contaminations in water causes convection to surface
Energy production in Alkali vents	Energy is released as heat as components of seawater are reduced S -> H2S N2 -> NH3 CO2 -> CH4
Why are alkali vents considered valid cradles of life? (5)	Has appropriate compounds that it can concentrate Fe-S catalyst Thermochemical gradient H2 gas for free energy Alkali environment on inside acidic environment of sea provides H+ gradient

Próximo

Descrição

Resumo de Recurso

Semelhante

	Criado por J yadonknow mais de 6 anos atrás