Proteolytic enzymes secreted from the pancreas are activated: a) within the lumen of the small intestine. b) once they reach the large intestine. c) in secretory vesicles within pancreatic secretory cells. d) once they reach the pancreatic duct.

A) within the lumen of the small intestine.

Explanation:

The pancreas produces a variety of hormone-like amylase, proteases, lipases which can digest the food material.

The proteases like chymotrypsinogen and trypsinogen are produced by the pancreas in their inactive form as if active will digest the organ itself. Therefore these zymogens are stored in the secretory vesicles which release the enzymes in the pancreatic duct.

These zymogens are not activated until they reach the digestive tract that is when these enzymes enter the lumen of the small intestine, the enterokinase present there catalyzes the trypsinogen to trypsin. Trypsin converts the chymotrypsinogen to the chymotrypsin.

Thus, Option-A is the correct answer.

the denominator has a very specific role.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.