Library.

“Salivary amylase cannot break down starch into glucose because the enzyme molecule is too large.”

The evidence shows salivary amylase does break down starch, just not primarily into free glucose. It begins starch digestion in the mouth by producing smaller sugars such as maltose and dextrins. The stated reason is also wrong: no credible source supports the idea that amylase fails to make glucose because the enzyme molecule is “too large.”

“Electrochemical enzyme-based biosensors can detect metabolites such as glucose and lactate associated with tumor metabolism.”

Published studies support that electrochemical enzyme-based biosensors can detect tumor-related metabolites such as glucose and lactate. Evidence includes cancer-cell and tumor-sample experiments using glucose- and lactate-oxidase sensors. The main caveat is that many demonstrations are proof-of-concept or ex vivo, so capability is established more clearly than routine clinical use.