Answer:
Pepsinogen is produced by chief cells and is activated by hydrochloric acid secreted by parietal cells.
Explanation:
Pepsinogen is a proenzyme produced in the chief cells (that are located in the stomach lining) that, when gets activated, is transformed into pepsin - a peptidase with the function to degrade proteins into amino acids.
The reason why pepsinogen is released inactive is that it would break down all of the cell's proteins because of its proteolytic nature. For this reason, it is released as a proenzyme and gets activated when reaches the acidic environment provided by the hydrochloric acid secreted by the parietal cells, also in the stomach lining.
Analyzing the proteins of the Racoons and lesser pandas, there will be huge similarities with minor modifications.
These species will be very closely related.
<h3><u>Explanation:</u></h3>
The evolutionary background of the species are mainly studied based on the similarities of the nucleotide sequences and proteins. While studying the Lesser pandas and Racoons, there was a huge similarities in then based on their structures, and on their protein composition. The nucleotide sequences also showed huge similarities which also points that they have developed from same ancestor. This is why they are very closely related with each other by means of evolution.