Chemical digestion involves enzymes. In the mouth, chemical digestion is initiated when the food comes in contact with saliva, which is secreted by salivary glands. It contains salivary amylase which begins the digestive process by breaking down starch and converting it into maltose. Chemical digestion then further continues in stomach and then finally in the small intestine.

Chemical digestion begins in your mouth. As you chew, your salivary glands release saliva into your mouth. The saliva contains digestive enzymes that start off the process of chemical digestion. Saliva also has an enzyme salivary amylase which begins the digestive process by breaking down starch and converting it into maltose. Chemical digestion then further continues in stomach and then finally in the small intestine. So, option 'A' is the correct answer.

Chemical Digestion in Alimentary Canal

Chemical digestion is the process of breaking down food into smaller molecules with the help of enzymes. The alimentary canal consists of several organs that play a role in chemical digestion. Let us understand from which part of the alimentary canal does chemical digestion begin.

Mouth

Chemical digestion begins in the mouth. The mouth contains salivary glands that secrete saliva. Saliva contains an enzyme called amylase, which helps in the digestion of carbohydrates. Amylase breaks down carbohydrates into smaller molecules called simple sugars.

Esophagus

The esophagus is a muscular tube that connects the mouth to the stomach. It does not play a role in chemical digestion.

Stomach

The stomach is a muscular sac-like organ that stores food and mixes it with digestive juices. The stomach secretes hydrochloric acid and enzymes such as pepsin, which help in the digestion of proteins. Hydrochloric acid creates an acidic environment in the stomach, which is required for the activation of pepsin. Pepsin breaks down proteins into smaller molecules called peptides.

Gallbladder

The gallbladder is a small organ located below the liver. It stores bile, a fluid that helps in the digestion of fats. When food reaches the small intestine, the gallbladder releases bile into the small intestine. Bile helps in the emulsification of fats, which means it breaks down large fat molecules into smaller ones.

Small Intestine

The small intestine is a long, narrow tube that is around 6 meters long. It is the main site of chemical digestion and nutrient absorption. The small intestine receives digestive juices from the pancreas and the liver. The pancreas secretes enzymes that break down carbohydrates, proteins, and fats. The liver produces bile, which helps in the digestion of fats. The small intestine also has enzymes on its surface that further break down carbohydrates, proteins, and fats.

Conclusion

In conclusion, chemical digestion begins in the mouth with the help of the enzyme amylase. It continues in the stomach with the help of hydrochloric acid and pepsin, and in the small intestine with the help of digestive juices from the pancreas, liver, and small intestine itself. The gallbladder releases bile into the small intestine, which helps in the digestion of fats.