What is L-Carnitine primarily responsible for in living cells?

L-Carnitine plays a crucial role in cellular metabolism, specifically in the transportation of fatty acids into the mitochondria, where they are oxidized for energy production. This process is vital because fatty acids are a primary energy source, especially during prolonged physical activity or when carbohydrate stores are low.

In living cells, L-Carnitine facilitates the transfer of long-chain fatty acids across the inner mitochondrial membrane, a critical step for beta-oxidation to occur. Once inside the mitochondria, these fatty acids can be metabolized to produce ATP, the energy currency of the cell. The efficiency of this process is particularly important for muscles and other tissues that rely heavily on fat for energy, making L-Carnitine essential for optimal energy production and exercise performance.

The other options do not accurately represent L-Carnitine's primary function. While glucose transport is essential for cellular energy, it is primarily facilitated by different transport proteins, and not by L-Carnitine. Breakdown of proteins and the formation of amino acids are also unrelated to the main function of L-Carnitine, which is firmly centered on fatty acid transport and metabolism.