Answers:
#1:
A phosphate group is just a <u>phosphorus atom bound to four oxygen atoms,</u> but it has many important roles. Along with sugars and bases, it makes up nucleic acids, like DNA and RNA. As part of energy carriers, like ATP, it provides energy for moving our muscles.
#2: Adenine stays unchanged and phosphate and ribose change.
#3: Energy can be released or absorbed when various <u>chemical bonds</u> form or are broken.
#4: Exothermic reactions release energy in the form of heat whereas <u>endothermic reactions</u> absorb energy.
#5:
When energy is needed by the cell, it is converted from storage molecules into ATP. Usually only the outer phosphate is removed from ATP to yield energy. When this occurs ATP is converted to adenosine diphosphate (ADP), the form of the nucleotide having only two phosphates.
