Video Transcript
Where is the majority of energy
stored in an ATP molecule? (A) In the bond between the ribose
sugar and the first phosphate group. (B) In the bond between the ribose
sugar and the adenine. (C) In the bond between the last
and middle phosphate groups. Or (D) within the ribose sugar.
This question is asking us about a
molecule called ATP. ATP stands for adenosine
triphosphate. It is the molecule which stores
chemical energy in living organisms. It allows cells to quickly access
the energy required for reactions and processes with no waste products produced.
As the diagram shows, ATP is made
up of an adenine base attached to a ribose sugar, which is attached to three
phosphate groups. So where is the majority of energy
stored in this molecule? The phosphate groups are connected
by energy-rich bonds. When energy is required by cells,
ATP is converted into ADP, adenosine diphosphate. During this process, the bond
connecting the last and middle phosphates is hydrolyzed. This releases the energy stored
within the bond.
We now have enough information to
answer our question. The correct answer is (C). The majority of energy in an ATP
molecule is stored in the bond between the last and middle phosphate groups.
