Can you recall the two chemical differences between DNA and RNA?
The two main chemical differences between DNA and RNA are:
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Sugar difference: RNA contains a 2′-OH group at every nucleotide (in ribose sugar), which makes it reactive, labile, and easily degradable. DNA lacks this 2′-OH group (it has deoxyribose sugar), making it chemically less reactive and more stable.
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Nitrogenous base difference: DNA contains thymine, whereas RNA contains uracil in its place. The presence of thymine instead of uracil confers additional stability to DNA.
These chemical differences explain why DNA is the predominant genetic material (more stable), while RNA performs dynamic functions like messenger and adapter roles, and acts as a catalytic molecule in some cases.
Explanation
The question specifically asks for chemical differences between DNA and RNA. From the textbook context, two key chemical differences are clearly stated: (1) The presence of 2′-OH group in RNA makes it labile and easily degradable, while DNA is chemically less reactive, and (2) Thymine in DNA replaces uracil found in RNA, which provides additional stability to DNA. These differences directly relate to why DNA is a better genetic material while RNA performs more dynamic functions.
Solution Steps
Step 1: Identify the sugar difference - RNA has 2′-OH group (reactive), DNA lacks it (stable)
Step 2: Identify the base difference - DNA has thymine, RNA has uracil