Chapter 25 Flashcards
First complex organic monomers develop in…
The Prebiotic “Soup”
Monomers join together to form…
Polymers
Protobionts form and maintain…
An environment different from their surroundings
Genetic material…
evolves
Oparin and Haldane
reducing atmosphere instead of an oxidizing atmosphere.
Miller and Urey
Amino acids from water, hydrogen gas, methane and ammonia
____ quantities of D and L amino acids formed.
equal
Molecules must be removed from system or they…
degrade
When was O2 present?
long before first cells
What was not part of the early atmosphere?
ammonia + methane– experiment fails without it.
how can polymers form?
reducing atmosphere, clay surfaces/iron pyrite=catalytic sites
oxygen in atmosphere…
prevents polymers from forming.
w/o O2 polymers…
form insufficiently and degrade spontaneously.
polymer formation is…
random, undirected
no monomers=
no polymers
protobionts- nucleic acids and polysaccharides can…
self assemble when shaken
protobionts- protein membrane is…
semipermeable-water can get through.
protobionts- lipids can form…
liposomes
problems w/ protobionts-
large amounts of protobionts can’t form to produce protobionts
without _____ protobionts can do nothing.
enzymes
1st genetic material-RNA
less complex, can self-replicate
1st genetic material- RNA produced in lab
40 nucleotides long
1st genetic material-RNA can act as…
enzyme called ribozyme and copy small RNAs
ribozymes must have…
very precise sequence
