Question

a student placed a test
containing a mixture of compounds into a beaker of water maintained at 30°c. a chemical reaction
took place and was com
sted in 30 minutes. a second test tube containing an equal amount of the same mixture plus
substance y was place
i the same beaker of water. the chemical reaction in the second test tube was completed in less than
one minute. substance y was most likely....
test tube 1
without substance y
water at 30°c
reaction time = 30 minutes
test tube 2
with substance y
water at 30°c
reaction time = less than 1 minute
a a sugar molecule.
b a lipid.
c a nucleotide.
d an enzyme.

Explanation:

Enzymes are biological catalysts that speed up chemical reactions. In the experiment, Tube 2 (with Substance Y) has a much faster reaction time (less than 1 minute) compared to Tube 1 (without Substance Y, reaction time = 30 minutes). This indicates that Substance Y likely acts as a catalyst. Among the options, enzymes are biological catalysts. Sugars (A) are energy sources, lipids (B) are for energy storage and membrane structure, and nucleotides (C) are part of nucleic acids. Only enzymes (D) fit the role of a catalyst that speeds up the reaction as shown in the experiment.

Answer:

D. an enzyme