The rate of cellular respiration is regulated by its major product, ATP, via feedback inhibition. As the diagram shows, high lev
els of ATP inhibit phosphofructokinase (PFK), an early enzyme in glycolysis. As a result, the rate of cellular respiration, and thus ATP production, decreases. Feedback inhibition enables cells to adjust their rate of cellular respiration to match their demand for ATP. Suppose that a cell's demand for ATP suddenly exceeds its supply of ATP from cellular respiration. Which statement correctly describes how this increased demand would lead to an increased rate of ATP production? a) ATP levels would fall at first, decreasing the inhibition of PFK and increasing the rate of ATP production. b) ATP levels would rise at first, decreasing the inhibition of PFK and increasing the rate of ATP production. c) ATP levels would fall at first, increasing the inhibition of PFK and increasing the rate of ATP production. d) ATP levels would rise at first, increasing the inhibition of PFK and increasing the rate of ATP production.
The correct answer is "They lack an independent metabolism"
Explanation:
Viruses are usually active/alive in a living environment and become inactive in non-living environment; these is because they rely on the metabolic activities of the invaded living environment/cell. This property is a sharp contrast to normal living cells that are able to metabolize different substances independently using several organelles.