Nucleic acids and the origins of life Flashcards
What is the function of nucleotides?
- Act as building blocks for nucleic acid polymer
- Storage, transmission and use of genetic information.
What bonds link nucleotides together?
Phosphodiester linkages in condensation reactions.
In what direction do nucleic acids grow?
5’-3’
What are the functions of RNA?
- structural and functional (catalytic)
- translation
Who disproved spontaneous generation?
Francesco Redi
What did Louis Pasteur’s experimentation exhibit?
That microorganisms can only arise from other microorganisms.
When did the chemical conditions on Earth become suitable to support life?
Around 4 billion years ago.
What are the two theories on the origin of life?
- Chemical evolution on primitive Earth
2. Small molecules of life came from space
What was found in fragments of meteorites in 1969?
Molecules unique to life like purines, pyrimidines, sugars and ten amino acids.
What did the molecules found in the meteorite fragments suggest?
That living organisms could have reached Earth within a meteorite.
What does the theory of chemical evolution suggest?
That conditions on primitive Earth led to the formation of simple molecules which led to life forms.
What abiotic conditions may have supported the formation of large molecules?
- Silicates within clay may have been catalysts
- Hot pools at ocean edges
- Hydrothermal vents
What is an activated nucleotide?
A nucleotide in which the 5’-phosphate is bound to a nucleophilic group by an amide linkage, thus releasing sufficient energy to drive polymerisation.
What does the RNA World hypothesis suggest?
That RNA stored genetic information and catalysed chemical reactions in primitive cells.
What does RNA’s ability to fold into highly elaborate structures allow it to do?
Serve as the catalyst ribozyme.
