The organ responsible for digestion is the stomach. It plays a crucial role in the digestive system by breaking down food into smaller, more easily absorbed components. When food enters the stomach, it is mixed with gastric juices containing acids and enzymes that further break down proteins and kill harmful bacteria. The stomach churns the food to enhance its mixing with these digestive juices, resulting in a semi-liquid substance called chyme. After the stomach, the chyme is gradually released into the small intestine, where further digestion and nutrient absorption occur, making the stomach essential for proper digestion.