A: The corneal reflex is an involuntary closing of the eyelids when the cornea is touched by a foreign object. The function of this reflex is to protect the eye from damage. Absence of a corneal reflex may indicate damage to the fifth and seventh cranial nerves, which mediate the reflex.
Cellular respiration is the process by which the chemical energy of food molecules is released and partially captured in the form of ATP. Carbohydrates, fats, and proteins can all be used as fuels in cellular respiration, but glucose is most commonly used as an example to examine the reactions and pathways involved.
Inside their cells, energy is extracted from the food in a process called cellular respiration. Cellular respiration requires oxygen (which is the by-product of photosynthesis) and it produces carbon dioxide, which is used in photosynthesis. In this way, photosynthesis and cellular respiration are linked in the carbon cycle.