It's a shallow layer of the upper mantle and lies directly below the litho spheres
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Full Question:</u>
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Trypsinogen is split by the enzyme enterokinase to form an activated molecule of the protease trypsin. Which of the following would confirm that the activation of trypsin is an example of how a positive feedback mechanism can amplify a biological process?
A. The activated trypsin enzyme can use enterokinase as a substrate
B. The trypsin produced by the reaction is capable of splitting and activating additional trypsinogen molecules
C. If levels of trypsin were to get too high, the trypsin molecules would inhibit the enzyme enterokinase
D. Each mRNA molecule that codes for trypsinogen can be translated repeatedly to form many peptide molecules
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Trypsinogen molecules are first split into the active enzyme Trypsin by enterokinase. Then the Trypsin being a protease itself, works on Trypsinogens and converts them to Trypsin. Thus this is a positive feedback.
Option B
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Explanation:</u></h3>
Trypsinogen is a proenzyme which is secreted by pancreas into the duodenum. Enterokinase is a intestinal enzyme that is secreted from the small intestinal glands. Enterokinase works on the Trypsinogens to convert them into trypsin by splitting a peptide chain from the proenzyme. This trypsin then digests a variety of proteins and peptides from diet.
Trypsin is a protease and the proenzyme Trypsinogen is a protein. So trypsin works on the secreted trypsinogens too and amplify the production of trypsin from the trypsinogens to enhance the digestion process. Thus, a positive feedback chain is seen here.
A Barrier Island is an island parallel to the coastline that protects the shore from erosion.
