Origin of life (week 4)

Question 1

when did the central dogma originate/ why is its function important

Answer 1

• dates back to the last universal common ancestor with roots in prebiotic chemistry
• transcribed to RNA, translated to proteins

dna to rna to proteins

Question 2

what is the bottom- up perspective on the origin of life

Answer 2

• many prebiotics where geochemistry might have allowed life to begin

Question 3

what is the top down approach in the origin of life and the problem with this

Answer 3

• biology formed first
• even simple components of a cell are massively complicated- metabolic/ catalytic systems so the question is posed weather they formed at the same time

Question 4

what is metabolism

Answer 4

• chemical reactions that occur in order to maintain life
• anabolic/catabolic

Question 5

did replication or metabolism come first

Answer 5

REPLICATION
- as rna can perform some of the enzymatic functions needed for replication
- These are called ribozymes

Question 6

what is the RNA world hypothesis

Answer 6

• RNA as information storage and metabolism control- movement in prebiotic chemistry
• rna is in alllllll life
• can self replicate and replicate other rna

possibility that RNA helped to form other forms of life

Question 7

what rna complementaty bases could have existed during early earth

Answer 7

• C and U
• different reaction conditions could have produced G and A but not C and U
  however mechanism shown in an rna world where all 4 nucleotides can be produced

Question 8

HOW PLAUSIBLE IS AN RNA WORLD

Answer 8

• WET-DRYING CYCLES
• METALS LIKE ZN,FE, CU
• SWINGS IN PH FROM STRONGLY ALKALINE TO MIDLY ACIDIC

Question 9

what does an rna world suggest

Answer 9

• exchange between multiple localities
• higwet dry cycles needed high temp= faster reactions
• iron- sulphur surfaces

Question 10

why are metals important in metabolism

Answer 10

so that enzymes can act as catalysts in biochemical reactions
- called metalloenzymes
- mg in chlorophyll in organic molecules
- Fe in hemoglobin in metalloproteins

Question 11

photoautotrophs

Answer 11

• light energy and carbon from co2

Question 12

photoheterotrophs

Answer 12

• light energy carbon from organic compounds

Question 13

chemoautotrophs

Answer 13

• energy from chem compounds carbon from c02

Question 14

chemoheterotrophs

Answer 14

• energy from chemical reactions and carbon from organics

Question 15

what type of reaction is metabolism

Answer 15

redox (electron transfer between reactants)
- oxidation
- reduction

Question 16

anaerobic vs aerobic respiration

Answer 16

-aerobic electron acceptor= oxygen

• anaerobic respiration= not oxygen (less energy made)

Question 17

what is the electron donor in chemolithotropy

Answer 17

inorganic