What happens to proteins in the body when they are converted into glucose?

When proteins are converted into glucose, they undergo a process called gluconeogenesis, which primarily occurs in the liver. This transformation is particularly important during periods of fasting or intense exercise when glucose reserves are low. In this context, proteins can be broken down into their constituent amino acids, which can then be converted into glucose to provide energy for the body's cells, especially for the brain and red blood cells that primarily use glucose as fuel. Therefore, the combustion of these amino acids contributes to maintaining blood sugar levels and supplying energy, supporting the notion that they are burned for energy in the body.

The other options do not accurately describe the fate of proteins when they are converted to glucose. For instance, while proteins are vital for muscle building, the specific mechanism of their conversion into glucose is not directly tied to muscle synthesis. Additionally, although excess glucose can be stored as glycogen or converted to fatty acids, the immediate fate of proteins being transformed into glucose is primarily for energy utilization, which is why this answer is the most accurate.