Multiple Choice
Which of the following is a structural polysaccharide in plant cells?
629
views
3
rank
9. Carbohydrates
Starch
Multiple Choice
In human digestion, which enzymes hydrolyze dietary starch in the mouth and small intestine, respectively?
A
Salivary in the mouth and pancreatic in the small intestine
B
Pepsin in the mouth and trypsin in the small intestine
C
Lactase in the mouth and sucrase in the small intestine
D
Bile salts in the mouth and gastric lipase in the small intestine
Verified step by step guidance1
Identify the substrate involved in the digestion process, which in this case is dietary starch, a polysaccharide composed of glucose units.
Recall that starch digestion begins in the mouth where an enzyme breaks down starch into smaller polysaccharides and maltose; this enzyme is salivary \( \alpha\text{-}amylase \).
Understand that starch digestion continues in the small intestine where pancreatic secretions contain enzymes that further hydrolyze starch; the key enzyme here is pancreatic \( \alpha\text{-}amylase \).
Recognize that pepsin and trypsin are proteases involved in protein digestion, not starch hydrolysis, so they are not responsible for starch digestion in the mouth or small intestine.
Note that lactase and sucrase are enzymes that hydrolyze disaccharides lactose and sucrose respectively, and bile salts and gastric lipase are involved in fat digestion, not starch hydrolysis.
Related Videos
Related Practice
