Question
Question 18 (1 point) Where do mechanical and chemical digestion take place in the digestive system? stomach; rectum stomach; small intestine mouth; large intestine mouth; stomach mouth; liver
Answer
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Amber
Master · Tutor for 5 years
Answer
B. Stomach; Small Intestine D. Mouth; Stomach
Explanation
## Step1: The question asks about the locations of mechanical and chemical digestion in the digestive system. First of all, it's important to understand what mechanical and chemical digestion actually means. Mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. In the human system, mechanical digestion begins in the mouth as food is chewed. Meanwhile, chemical digestion refers to the breakdown of the food into simple nutrients that can be used by cells, which involves fragmenting it into small beneficial substances with the help of enzymes and other chemicals. The chemical component, however, has multiple stations throughout the digestive tract where different enzymes are introduced, including the mouth, stomach, and the small intestines.## Step2: Mechanical digestion primarily occurs in the mouth where teeth mechanically break down food, and in the stomach, where chewed food is churned with gastric juices to form a semi-solid mixture known as chyme.## Step3: In terms of chemical digestion, it begins in the mouth with the introduction of amylase, an enzyme in saliva that begins the breakdown of carbohydrates. However, the majority of chemical digestion occurs in the stomach and small intestine. In the stomach, enzymes and hydrochloric acid break down proteins, and in the small intestine, various nutrients are further broken down and absorbed.