Imagine eating a soda cracker, which is basically starch, fat, protein, and salt. How would each of these components be digested? Where within the digestive system would they be digested? Are any accessory organs involved?

Answer 1

Digestion begins in the oral cavity. Food triggers saliva from the parotid salivary glands, rich in amylase, and from the submandibular salivary glands, rich in mucus. The tongue and teeth cooperate to mix all together and form a bolus. Digestion of fats and starch begins due to lingual lipase and salivary amylase. Swallowing reflexes send it to the stomach. Acid and pepsin mix with the bolus. Peptides form from the wheat proteins due to action of pepsin. It then travels into the small intestine, where pancreatic lipase and amylase complete fat and starch digestion. Pancreatic proteinases and peptidases reduce peptides to amino acids. These are absorbed by cotransport. Maltose from starch is split into glucose molecules, which are absorbed by cotransport. The salt in the cracker is absorbed during cotransport. Fatty acids diffuse into the epithelial cells because of their lipid character.