Topic 4-1 Flashcards
How long ago was the earth formed?
4.6 billion years ago
What were the conditions of the primordial earth?
- frequent and intense lightning
- volcanic activity
- primitive atmosphere
- NO o3 layer
- intense uv rays
- reducing atmosphere
what evidence was found in greenland? what did it suggest? and how old is it?
carbon isotopes
3.8 bya
suggest that this is when organic molecules were generated.
define stromatolite
- dome shaped rock formed when microorganisms bind particles of sediment together, forming thin sheets
what were the earliest fossils
stromatolites
how far back to stromatolites date back?
3.4 bya
what is the definition of life?
- ## No definition - its too hard to make a universal definition
what is NASA’s definition of life?
a self sustaining system capable of Darwinian evolution
What is wrong with NASA’s definition of life?
there are things that can’t evolve but are living…. mules
Why might a virus be considered alive or not?
- alive - b/c contain nucleic acid and replicate and evolve rapidly
- not alive - b/c they don’t make their own proteins and cannot complete life cycle without invading other living cells
What are the & key characteristics shared by cellular life forms?
- Order
- Harness and utilize energy
- Reproduce
- respond to stimuli
- exhibit homeostasis
- grow and develop
- evolve
What defines a cell?
- metabolism
- reproduction
- composition- complex organic molecules
What is metabolism?
Process through which organisms produce and consume energy to sustain themselves
define reproduction
all cells arise from previous cells
what are the complex molecules that make up cells?
protein
carbs
lipids
nucleic acids
in order for living cells to emerge what needs to happen?
- a means of reproduction
- formation and aggregation of organic molecules
how many steps are there to producing simple cells?
4
what are the 4 steps/stages to producing simple cells?
1 - abiotic synthesis of small organic molecules
2- Joining these small molecules into macromolecules
3 - package molecules into protocells
4- origin of self replicating molecules
explain step 1 - abiotic synthesis of small organic molecules
the reducing atmosphere present in the primordial earth created a potential for the abiotic synthesis of aa sugar lipids nucleotides
miller-urey supported this
whos hypothesis was abiotic synthesis of small organic molecules
- oparin/haldane
the Miller- urey experiments did what?
supported the oparin/haldane hypothesis -
- their experiments showed that the abiotic synthesis of organic molecules in a reducing atmosphere is possible
according to the abiotic synthesis of small organic molecules (miller-urey experiment) organic molecules can be synthesized spontaneously under the conditions _______________
simulating the primordial earth
what is step 2 to the origin of life?
Formation of polymers
explain - the formation of polymers step
on earth - RNA monomers produced spont from simple molecules
- experiment with hot sand, clay, rock
in space - interstellar star - 4.5 by old chondrite containing 80+ amino acids
