The correct option is D.
Cellular respiration is the process by which the body breaks down the sugar molecules that are eaten in food with the aid of oxygen and covert them into energy, carbon dioxide and water are also produced as by products. Cellular respiration and fermentation are both involved in the breaking down of sugars but cellular respiration occurs in the presence of oxygen while fermentation occurs in the absence of oxygen. Carbon dioxide is breath out by the lungs during cellular respiration.
The answer to this is protein.
Hydrochloric acid in digestive system is found in stomach, which is the only main digestive organ with an acidic pH 2.
In the stomach, only one kind of the primary food substance is chemically digested, which is protein. It is digested with the help of enzyme Pepsin, which breaks protein chains into polypeptides.
After that, the other organs of the digestive system has more of a neutral to slightly alkali condition, which is not related to hcl. Therefore, the answer is protein.
MASS: because it is the measure of the amount of matter in an object
1 ) under water earthquakes cause a disturbance sending water outwards away from the point of the earthquake due to air and pressure coming into contact at gray force