Mitochondria - Cell organelles that metabolize sugars into energy. Mitochondria also contain DNA, which is damaged by the high level of free radicals produced in the mitochondria. Photoaging - The process initiated by sunlight through which the skin becomes drier and loses elasticity. Photoaging is being studied for clues to aging because it has the same effect as normal aging on certain skin cells. Proteins - Molecules made up of amino acids arranged in a specific order determined by the genetic code.
Proteins are essential for all life processes.
Certain ones, such as the enzymes that protect against free radicals and the lymphokines produced in the immune system, are being studied extensively by gerontologists.