Carbohydrates are a source of energy. When broken down, the body uses them to power all its functions.
<span> C) It was once underwater; now it is not. </span>
Answer:
Pepsin
Explanation:
An enzyme made in the stomach that breaks down proteins in food during digestion. Stomach acid changes a protein called pepsinogen into pepsin.
Endotherms, such as birds and mammals, use metabolic heat to maintain a stable internal temperature, often one different from the environment. Ectotherms, like lizards and snakes, do not use metabolic heat to maintain their body temperature but take on the temperature of the environment.
