Flashcards in Lecture 16 - Origins of Life Deck (30):
1
What are the 7 ways that life is defined?
1. metabolism
2. reproduction
3. cellular organization
4. homeostasis
5. growth
6. adaption
7. response to stimuli
2
Evolution is a theory about the origin of life (T/F)
False
3
What did Darwin believe about all organisms?
They trace back to a single ancestor
4
Was life on earth possible at the beginning?
no
5
What happened 4.6 billion years ago?
formation of earth
6
What happened 4.2 BYA? What did that encompass?
-stable hydrosphere
1. bombardment ends
2. earth cools
3. oceans form
7
What is prebiotic chemistry? What years?
-4.2-4.0 BYA
1. abiotic synthesis of small organic compounds
2. joining of small molecules into macromolecules
3. packaging of molecules into protocells
8
What are some examples of small organic compounds?
CH4
9
What is an organic compound?
C with H bonds
10
What is the Oparin-Haldane hypothesis?
-atmosphere was reducing (electron adding)
-catalyze reactions to form more complicated organic molecules from simpler molecules.
-energy for synthesis may have come from lightning + UV radiation
11
Who was Stanley Miller?
-Chicago student
-made contraption (added lightning to simple compounds)
-tested Oparin-Haldane hypothesis
-found amino acids after 7 days
12
What are 3 ways that organic compounds could have been formed?
1. under volcanic or hydrothermal conditions
2. hydrothermal conditions
3. brought to Earth on meteorites
13
What year was the Miller Urey experiment?
1953
14
What are macromelcules
EX: amino acids into proteins
15
What serves as catalysis for macromolecule formation?
clay surfaces
16
What are protocells?
aggregates of abiotically produced molecules surrounded by a membrane/membrane-like structure
17
What do protocells exhibit?
-simple reproduction and metabolism
-maintain internal chemical environment
18
How are protocells formed?
could be spontaneous
19
When does vesicle self-assembly accelerate?
in the presence of a substrate
20
What happened 4.0 BYA
pre-RNA world
21
What happened 3.8 BYA
RNA world
22
What are 4 functions of RNA?
1. catalyzes reactions (ribozymes)
2. central to protein synthesis
3. self-replicating
4. stores information
23
What happened 3.7 BYA
first DNA/protein life
24
Why was the first DNA/protein life stage so important?
oldest possible life forms
25
When was earth formed?
4.6 billion years ago
26
What are stromalites?
-layers of rocks
-composed of layers of cynaobacteria separated by sediment
27
What is LUCA?
last universal common ancestor (3.6 billion years ago - present)
28
Was life possible 4.6 BYA? Why or why not?
-no
1. extreme heat
2. water vaporization
3. bombardment
29
What were 3 characteristics of the last universal common ancestor?
1. thermophilic
2. anaerobic
3. autotrophic
30