Lecture 16 - Origins of Life Flashcards Preview

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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

What may have proceeded RNA as the genetic code?

peptide nucleic acid