Digestion in Humans
As humans, we use peristalsis to push food down into our stomach, where strong acids break up the food while it is churned. Then, it enters the small intestine, where villi absorb nutrients, aided by their large surface area. In the large intestine, excess water is absorbed and the remaining waste leaves the body as feces. Glucose is the most important molecule to enter our bodies. Glucose comes in starches. When starch enters the mouth, enzymes break it up into glucose so that it is small enough to pass through cell membranes, where it then is transported through active transports into the human cells. Glucose and oxygen join together in the process of cellular respiration to produce carbon dioxide, water, and most importantly ATP. ATP is a three-bond molecule that gives us energy. When we need energy, we break one of the bonds and it releases energy for us to use. After we've used the energy, we have ADP, which is a two-bond molecule without energy. We must perform cellular respiration to get ATP again.
Digestion in Cowrie Snails
In Gastropodas, the radular motion in the mouth, or forcing food forward and quickly retracting, puts food particles into the mouth. The movement of cilia, or ciliary currents, pushes food along the digestive track. Different salivary and digestive glands release enzymes in the buccal cavity (or cavity between the jaw and the mouth) and the stomach. Digestion takes place in the buccal cavity and the stomach. Food can be stored during periods of inactivity in the apical digestive gland, or liver. [1]
DIGESTION DIAGRAM: CLICK HERE
DIGESTION DIAGRAM: CLICK HERE