Answer:
Enzymes help speed up chemical reactions in the human body. They bind to molecules and alter them in specific ways. They are essential for respiration, digesting food, muscle and nerve function, among thousands of other roles.
Explanation:
Answer:
Chemicals that are secreted from antigen-presenting cells then activate helper T cells.
Explanation:
<span>since plants are at the bottom of the food web and provide the most energy</span>
