What role does gastric juice play in digestion?

Gastric juice plays a crucial role in digestion, particularly in the breakdown of proteins. It contains hydrochloric acid and digestive enzymes, most notably pepsin, which is specifically designed to denature proteins and facilitate their digestion into smaller peptides. The acidic environment created by gastric juice not only activates pepsin but also helps to kill bacteria and provides a suitable pH for further digestive processes in the intestines.

In contrast, the other functions listed do not accurately describe the role of gastric juice. Emulsifying fats occurs primarily in the small intestine with the help of bile, not gastric juice. Absorption of carbohydrates takes place mainly in the small intestine, where enzymes break them down into simpler sugars for absorption into the bloodstream. Lastly, the regulation of blood sugar is managed by hormones such as insulin and glucagon rather than the processes involving gastric juice.