Now, the next question is why do we have to use a catalyst? Why do we need to use an enzyme for this reaction to actually take place inside our body? Well, as it turns out, as we'll see in just a moment, the rate at which the reaction takes place is very, very low. So let's take a look at this particular reaction. So we have the peptide bond between the carbon and nitrogen shown in purple. And what this describes is the hydrolysis of the peptide bond.