Origin of life Flashcards
What certain characteristics do all living organisms share?
Composed of cells, levels of organisation, use energy, respond to stimuli, grow, reproduce, adapt to environment, maintain homeostasis.
What certain chemistry do all living organisms share?
Carbon-based, use energy, use oxidative gradients, contain proteins lipids carbs, use nucleic acids for heredity, use ATP, have same basic metabolic reactions.
How old is the universe?
13,700,000,000 years old.
What was the beginning of the solar system?
Explosion of star, formation of compounds, heavy metals, dust collapse, nebula, rotation round point.
How were dust cloud Coalesces formed?
Gravity takes over, rotation round point, spinning flattens cloud into disc, collision between particles, planets form, sun compress ignites.
How did planets form?
Inner planets form from mineral solids, outer planets form from gases, planetessimals.
How were protoplanets formed?
Major collisions, gas giants form.
What happened when the sun ignited?
Inner planets still chaotic and small, Jupiter supports asteroid belt.
How was the moon formed?
Earth increases in size with protoplanet companion, collision.
What happened during late heavy bombardment?
Sterilises earth, water falls to earth, meteorites fall.
What were some implications of the early solar system?
Hydrogen abundant, high energy interior, magnetic field, atmosphere, meterorites, comets.
Where did all the water come from?
Comets from late heavy bombardment, minerals dissolved in water, water covers planet.
What happened during the hadean eon?
Earth spinning rapidly, smoggy toxic environment, dust/ash in atmosphere, anaerobic, surface water, violent tides, acidic, boiling sea.
What is the panspermia theory?
Living organisms seeded by meteorites, identified from mars, mineral deposits, possible fossils.
What have been detected on a non-terrestrial asteroid?
Nucleic acids uracil and nicotinic acid.
What is the mineral clay theory for origin of life?
Water-bearing clays from concentration vessels for replication and patterning, source of mineral salts for catalysis of early processes, largely unsupported or supplanted.
What is the primordial soup theory of origin of life?
Key elements react and form basic compounds for life - amino acids, nucleic acids, carbon based, spark of life from high energy source.
What were the Miller-Urey experiments?
Replicated conditions of early earth based on predicted atmosphere of Jupiter, water, ammonia, methane, hydrogen, energy spark from lightening.
What were the steps of the Muller-Urey experiments?
Mixture of liquid heated to gas, gases mix with spark, condenser, products collected and analysed.
What was the outcome of the Muller-Urey experiments?
Amino acids were formed via Formaldehyde, conc of key components and energy from lightning could form building blocks of proteins.
What are some major problems of the Muller-Urey experiments?
Analysis of early rocks shows atmosphere was CO2, N2, H2S, SO2, cant make AAs from these.
What are some problems with primordial soup?
Unlikely to happen spontaneously, more complexity needed, energy source, concentration problem.
What is all life based on?
Reactions of hydrogen and oxygen, free energy, reactions can be spontaneous.
What is needed to drive reactions?
H+ gradients.
What is all life based on?
Reactions of hydrogen and oxygen, free energy, reactions can be spontaneous, need gradients.
What are proton gradients important for?
Producing reducing potential for chemical reactions.
What is the importance of deep sea vents?
Massive biodiversity, archaea, prokaryotes, animals.
What are black smokers?
Acidic, high pressure, iron pyrites, H2S released, +O2 — energy, flat eqm.
What is an alternative to the black smokers reactions due to little O2?
2H2S + Fe — FeS2 + 4H+ (not sufficient to fix CO2, more reactive CO works).
What are alkali vents?
Acid vents caused by moving plates, causes fusion or submergence, crust splits open and moves apart, exposes mantle, sea water in, meets magma, water and minerals + magma = serpentine rock.
What is serpentination for alkali vents?
Rocks mix with mantle, give up seawater, contaminations in water cause convection, forces magma to ridges, continuous activity driven.
What are the actions of alkali vents?
Releases energy as heat, reduces components of seawater, H2, S—H2S, N2 — NH3, CO2 — CH4 (components to produce AAs).
What are natural flow reactors made of?
Tynagh rock was hollow alkali vent chimneys are hollow, small cells some of them microscopic.
What is the purpose of natural flow reactors?
Appropriate compounds, concentrates compounds, provide Fe-S catalyst, thermochemical gradient, H2 gas for free energy.
What are porous cells?
Bioreactors.
