Rephrase the law of conservation of mass in your own words

The law of conservation of mass basically says that nothig can be "created" or "destroyed" but that thigs just under go transformations and change into something else. For example, take a pile of wood. If light it on fire it doesnt disappear, i have just changed it into ash and thermal energy.

Glucose, also called grape sugar, blood sugar or corn sugar, is among the simplest and one of the primary naturally occurring sugars. produced naturally by plants as the primary photosynthesis product, it is heavily used by living beings as a main energy source and is necessary for cellular respiration. chemically, it is a monosaccharide carbohydrate and serves as a building block for complex sugars like starch.

The answer to this will be from your lab notes/procedure. it would be best to ask another student who participated in the lab as we do not know what was done, what enzyme or if the temperature is celsius or fahrenheit. if i were to guess though i'd say the rate stopped due to enzyme denturing at high temperature