no ptyalin is not secretes by the cells in the stomach
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The enzyme ptyalin ,or salivary amylase acts on starches and
converts them to maltose.
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Ptyalin is an enzyme, which means that it is made up of
proteins. When a protein enters the stomach, it is denatured by
HCL, which is a kind of acid. This results in the Ptyalin no longer
being effective.