According to the lock and key model of enzymes, which of the following would be the most likely substrate?

Lesson Worksheet:Enzyme Action | Nagwa
a
V
b
X
c
Y
d
Z
e
A realistic substrate is not shown in the diagram.

The most likely substrate would be option c, Y. According to the lock and key model, the substrate (Y) fits into the active site of the enzyme (represented by the keyhole) like a key fitting into a lock.

According to the lock and key model of enzymes, the most likely substrate would be depicted in the diagram by the letter V. Therefore, the answer is option a.