The word sponge is more appropriate to use than Underground river since an underground river can loose water while an aquifer cannot loose water, unless it is open-air and above ground. then the aquifer would slowly loose water due to evaporation from the sun.
Prokaryotic cells do not have membrane bound organelles. Eukaryotic cells do have membrane bound organelles. The membrane controls movement in and out of the cell. ... The cytoplasm fills the space between the nucleus and the cell membrane.
Activation energy is the minimum quantity of energy that the reacting species must possess in order to undergo a specified reaction.
for example , striking a match on the side of a matchbox provides the activation energy, in the form of heat produced by friction.
NADP is the most abundant acceptor for hydrogen released in the Krebs cycle.