Beginning of Life and Synthetic Biology Flashcards Preview

BS3000 Evolutionary Genetics UOL > Beginning of Life and Synthetic Biology > Flashcards

Flashcards in Beginning of Life and Synthetic Biology Deck (29)
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1
Q

What did ‘fertile atmosphere’ experiments generate?

A

Amino acids
Bases - Adenine, Guanine, Uracil
ATP, Coenzyme A
Ribose

2
Q

What can NH3 be made from?

A

(FeS) + N2 + H2O

3
Q

What does HCN hydrolysis provide?

A

All of the nucleotides

4
Q

What can aldehydes be made from?

A

CO2 and H2O

5
Q

What are polyphosphates made from?

A

Meteor impacts in the oceans at 2000 degrees C

6
Q

Why was primeval broth view experimentally criticised?

A

Too much H2
CH4, CO minor components
CO2 and N2 major components
‘Prebiotic soup’ - oceans - molecules too dilute to react

7
Q

When was the RNA world predicted to be?

A

3.5-4 million years ago

8
Q

What is the simple meaning of being living?

A

Anything that replicates is living

9
Q

Which rRNA makes only RNA?

A

23S rRNA

10
Q

What is special about the 23S RNA intron?

A

It splices itself out without any help from proteins

11
Q

What does the 23S RNA intron need to splice itself out?

A

Free 3’ hydroxyl group of guanine nucleotide / nucleoside which attacks 5’ end of intron

12
Q

What can the tetrahymena intron do?

A

1) Make and break bonds between tRNA and amino acid

2) Generate a poly-cytosine nucleotide strand, make and break phosphodiester bonds between nucleotides

13
Q

What did Carl Woese find (1987)?

A

rRNA genes more conserved than ribosomal protein coding genes

14
Q

What does rRNA provide and what does the protein provide?

A

The catalytic component for protein elongation, proteins provide scaffold

15
Q

What does montmorrillonite clay do?

A

Attracts nucleotides promoting polynucleotide formation even in dilute solutions
Promotes vesicle assembly - membranes and encapsulation

16
Q

What does RNA need to replicate?

A

One ribozyme, plus one complementary copy to act as a template

17
Q

Why are errors in copying necessary?

A

For evolution to take place

18
Q

What stabilises replicase RNA?

A

Amino acid (+ charge) - Selection for the first tRNA

19
Q

What stabilises the RNA?

A

Amino acids - beginning of RNP world

20
Q

What was the initial ‘tRNA’ function in?

A

Replication

21
Q

What do many retroviruses have?

A

3’ tag with terminal CCA - signal for replication

22
Q

What identifies a molecule as a substrate for replication and where does replication start?

A

3’ lops plus terminal CCA

Replication initiates at first C of CCA

23
Q

What do stem loops do?

A

Provide catalytic potential

Provide dsRNA regions, so complimentary RNA strands formed

24
Q

What is the ‘iron-sulphur world’ theory?

A

Metal sulphides (FeS) catalysed reactions to generate amino acids under high pressure and intense heat (up to 250 degrees)

25
Q

What is carbonyl sulphide (COS) and what does it do?

A

Volcanic gas
In the presence of L-phenylalanine mediates the condensation to dipeptide. Mediates mixed peptide condensation with metal sulphides from single mixture of L, F, S, A, Y

26
Q

What came first: translation or replication?

A

Translation

27
Q

Why did RNA world give rise to DNA world?

A

DNA is more stable, better replicator

28
Q

Which enzymes change RNA to DNA?

A

Ribonucleotide reductase: Ribose to deoxyribose

Reverse transcriptase: RNA to DNA

29
Q

What are the three classes of ribonucleotide reductase?

A

Aerobic
Independent of O2 but cobalt-dependent
Anaerobic