Enzymes catalyze reactions by lowering the activation energy of the reaction. Enzymes are made of proteins, and therefore the answer here is B. Protein molecules.
It is b because of all the cells that produce the chemical bond
Living, single, grow, produce, community, interactions, non living, environment, organisms, species, interbreeding
The swallowing mechanism consists of three stages, beginning with the oral phase that begins in the mouth. The second stage, called the pharyngeal phase, triggers the swallowing reflex that moves food through the throat, or pharynx. During the pharyngeal phase, the larynx closes and breathing stops while food begins to move through the throat to the esophagus. The closing of the larynx is accomplished by the epiglottis. During the third stage, food is moved down the esophagus to the stomach.
Scalars and vectors describe an object motion.
