AP BIOLOGY

ANIMAL PHYSIOLOGY

DIGESTION IN HUMANS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Where does chemical digestion begin?
A
mouth
B
esophagus
C
stomach
D
small intestine
Explanation: 

Detailed explanation-1: -Chemical digestion in the mouth is minor but consists of salivary amylase (ptyalin, or alpha-amylase) and lingual lipase, both contained in the saliva. Salivary amylase is chemically identical to pancreatic amylase and digests starch into maltose and maltotriose, working at a pH optimum of 6.7 to 7.0.

Detailed explanation-2: -Chemical digestion begins in your mouth with your saliva. The process continues in your stomach and is completed in your small intestine. The majority of chemical digestion takes place in your small intestine.

Detailed explanation-3: -Saliva contains special enzymes that help digest the starches in your food. An enzyme called amylase breaks down starches (complex carbohydrates) into sugars, which your body can more easily absorb. Saliva also contains an enzyme called lingual lipase, which breaks down fats.

Detailed explanation-4: -The large pieces of food that are ingested have to be broken into smaller particles that can be acted upon by various enzymes. This is mechanical digestion, which begins in the mouth with chewing or mastication and continues with churning and mixing actions in the stomach.

Detailed explanation-5: -Saliva Moistens Food and Begins the Process of Chemical Digestion. Saliva secreted by salivary glands aids the mechanical and chemical process of digestion.

There is 1 question to complete.