AP BIOLOGY

ANIMAL PHYSIOLOGY

DIGESTION IN HUMANS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Which type of digestion occurs in the mouth when an individual chews a piece of bread?
A
mechanical digestion, only
B
chemical digestion, only
C
both mechanical and chemical digestion
D
neither mechanical nor chemical digestion
Explanation: 

Detailed explanation-1: -Mechanical digestion in the oral cavity consists of grinding of food into smaller pieces by the teeth, a process called mastication. Chemical digestion in the mouth is minor but consists of salivary amylase (ptyalin, or alpha-amylase) and lingual lipase, both contained in the saliva.

Detailed explanation-2: -Mechanical digestion is a physical process in which food is broken into smaller pieces without becoming changed chemically. It begins with your first bite of food and continues as you chew food with your teeth into smaller pieces. The process of mechanical digestion continues in the stomach.

Detailed explanation-3: -Mechanical Digestion 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-4: -Mechanical digestion is a purely physical process that does not change the chemical nature of the food. Instead, it makes the food smaller to increase both surface area and mobility. It includes mastication, or chewing, as well as tongue movements that help break food into smaller bits and mix food with saliva.

Detailed explanation-5: -Mechanical digestion begins in your mouth with chewing, then moves to churning in the stomach and segmentation in the small intestine. Peristalsis is also part of mechanical digestion.

There is 1 question to complete.