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Bread Digestion and Sweet Taste
In the investigation, the student put a square piece of bread into their mouth, did not chew it and recorded the time taken for the bread to taste sweet.
During the investigation, the bread began to taste sweet in the student’s mouth.
Explain why the bread tasted sweet.
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Marking points
- 1 Identifies a carbohydrate source in the bread: starch, or the accepted alternative of sugar/glucose.
- 2 Explains how soluble sugar becomes available: starch is broken down, or existing sugar dissolves in saliva.
- 3 Links the change to salivary amylase or to dissolved sugar reaching taste receptors.
Full-mark answer
Bread contains starch. Amylase in the saliva breaks the starch down into sugars such as maltose, and the dissolved sugar reaches taste receptors on the tongue, producing the sweet taste.
Why this answer loses marks
Amylase makes the bread sweet.
This names the enzyme but does not say starch is broken into sugar or that dissolved sugar reaches taste receptors.