Question

In protein synthesis, the selection of a particular amino acid is determined by the so-called genetic code, or a sequence of three bases in DNA. Will a sequence of only two bases unambiguously determine the selection of 20 amino acids found in proteins? Explain.

Short answer

No, a sequence of only two bases cannot unambiguously determine the selection of 20 amino acids. This is because there would only be 16 possible combinations, which is less than 20, the total number of amino acids.

Step-by-step solution

Understand the four different bases in DNA

There are four kinds of nitrogen bases in DNA, which are adenine (A), thymine (T), guanine (G), and cytosine (C).

Calculate the number of permutations with two bases

If a combination of two bases were to be used to encode an amino acid instead of three, then the number of possible permutations would be \(4^2\) (since for each position, there are four possible bases), which is 16.

Compare the number of permutations with the number of amino acids

However, there are 20 different types of amino acids found in proteins. Since 16 is less than 20, this implies that some amino acids would share the same code if only two bases were used, leading to ambiguity.

Reasoning

Therefore, a sequence of only two bases cannot unambiguously determine the selection of 20 amino acids.