Foods are broken down into their building blocks by adding water. This would be an example of which characteristic of water?

Foods are broken down into their building blocks by adding water. This would be an example of which characteristic of water?

a. water has a high heat of vaporization.

b. water acts as a cushion.

c. water acts as a lubricant.

d. water acts as a reactant.

d. water acts as a reactant.

Explanation:

During chemical digestion of food nutrients into simpler substances, water serves as a reactant. Water molecules dissolve the food particles to facilitate the digestive activities of the digestive enzymes. The water present in saliva mix the food particles and form a semi-solid bolus. Starch molecules present in the bolus are reacted upon by the salivary amylase in the presence of water only. Similarly, chemical digestion of proteins and lipids in the stomach and small intestine requires presence of water.

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.