Is an oxygen atom covalently bonded to a carbon atom positive, negative, partial positive or partial negative?

The correct answer is c

Processes above and be sure to mention the movement of electrons and energy as the carbon atom moves from one reaction to another.

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