what does it mean when it says an enzyme, IE polymerase, has high fidelity? what is "fidelity" referring to?

Answer 1

A DNA polymerase has high fidelity when it introduces errors in the newly synthesized DNA strand at a very very low rate.

Answer 2

Think of 'fidelity' as in spousal fidelity. The husband and wife exhibit 'fidelity' when they only mate with each other. An enzyme that only 'mates' with a specific substrate has 'high fidelity'. An enzyme with 'low fidelity' reacts with many different substrates.

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