Question

Which is a high-energy compound in muscles?
A. Glucose
B. Starch
C. Glycogen
D. Creatine phosphate

Answer 1

Hint:
High-energy compounds refer to those compounds that are rich in energy. In quantifiable terms, compounds that yield -7.3kcal/mol of energy or greater on hydrolysis are termed as High energy compounds. These usually contain phosphates.

Complete answer:
Glucose is not a high-energy compound but on hydrolysis, it yields ATP. It is stored as glycogen in the muscles.
Along with the help of oxygen and certain enzymes, glucose is broken down in a series of steps. This process finally gives ATP and Creatine phosphate.
Starch, a polysaccharide, consists of units of glucose joined by glycosidic bonds, that is: amylopectin and amylose. It is a low-energy compound.
Creatine phosphate in muscles is a high-energy compound. It yields -10.3 kcal/mol energy which is more than that of ATP. ATP yields -7.3 kcal/mol energy. It is found in muscles to perform the task of contractions. These help in replenishing more ATP. Thus, these are used by athletes/sportspeople to produce more energy. Also, it is quite easy for this compound to be generated.
Thus, the correct answer is Creatine phosphate.

Option ‘D’ is correct

Note:
The energy released is also called free energy. The ’-’ sign indicates that this free energy is released from an exothermic reaction. It is a thermodynamic property and is also known as Gibbs free energy.
Higher energy is produced by Phosphocreatine but ATP is the most commonly used molecule to gain energy. Its breakdown releases creatine which if increased in the body can cause many health problems.