How would the hydrolysis of phosphodiester bonds impede the origin of life?

Question

A.  It would slow the rate of protein synthesis.
B.  It would prevent the assembly of nucleic acids.
C.  It would stop the formation of cell membranes.
D.  It would digest amino acids.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
 
Gather Content
· What do you already know about the molecular basis of early life-forms?

  Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?


Answer 1

B.  It would prevent the assembly of nucleic acids.

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses the molecular basis of early life-forms.
· What type of thinking is required?
        o This question is asking you to take what you already know and apply it to this unfamiliar situation.
 
Gather Content
· What do you already know about the molecular basis of early life-forms?
        o Early life-forms needed both information molecules and enzymes. RNA may have served both functions at once.
        o Although most enzymes are proteins, RNA can catalyze reactions as well as store genetic information.
        o According to the RNA world hypothesis, RNA, rather than DNA, was the first nucleic acid that permitted self-replication, an important step toward life.
        o Later DNA, which is more stable than RNA, took over the information storage function.

  Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Both RNA and DNA have a backbone made of a series of phosphodiester bonds.
        o So hydrolysis – breaking – of the phosphodiester bonds would have interfered with formation of strands of these nucleic acids.
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o The question required you to take what you already know and apply it to this unfamiliar situation.
        o Did you recognize that phosophodiester bonds comprise the backbone of both DNA and RNA?