Answer:
Brain ----- glucose and amino acids.
Heart ------- fatty acids and triglycerides.
Explanation:
The sources of energy utilized by the brain is glucose under well-fed whereas the sources of energy utilized by the heart under well-fed condition is fatty acids. During starvation, the source of energy used by the brain is amino acids from skeletal proteins when glucose is not available while on the other hand, during starvation, the heart utilized triglycerides as a source of energy in the absence of fatty acids.