Structurally
DNA and RNA<span> are nearly identical. As mentioned earlier, however, there are three fundamental </span>differences<span> that account for the very </span>different<span> functions of the </span>two<span> molecules. </span>RNA<span> has a ribose sugar instead of a deoxyribose sugar like </span>DNA.RNA<span> nucleotides have a uracil base instead of thymine.
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p.s (google helped)
It is likely to be a negative feedback. D is formed from B or C. D reduces the activity of the enzyme that converts A.
Cellular Respiration is used to break down glucose into ATP.
