The contraction of the gall bladder is due to:

Digestion of carbohydrate is affected by

All of the following are gastrointestinal hormones except $-$

$A$: Trypsin is an example of an endopeptidase and is present in the pancreatic juice.
$R$: Trypsin acts on the interior peptide bonds of a protein molecule.

How are the activities of the gastrointestinal tract regulated?

$A -$ Secretin acts on the exocrine pancreas and stimulates the secretion of water and bicarbonate ions. $R -$ Cholecystokinin $(CCK)$ acts on both the pancreas and the gall bladder and stimulates the secretion of pancreatic enzymes and bile juice,respectively.