BIOL 221 Lecture Notes - Lecture 9: Citric Acid Cycle, Hemosiderin, Thyroid
Document Summary
Myoglobin (o2 in skeletal and cardiac muscle; a&p i) Proteins are also essential to storage of certain substances within cells. For example, hemosiderin and ferritin are used to store iron. Myoglobin stores oxygen in skeletal muscle and cardiac muscle. Thyroglobulin stores thyroxine in the thyroid gland. The least important role of protein is to serve as a source energy to produce atp through aerobic metabolism. Amino acids can be converted to pyruvic acid or krebs cycle compounds and then metabolized. This is especially important when dietary intake of carbohydrates or lipids is low. Intake (through diet) equals loss (through feces and urine) The body is said to be in nitrogen balance when intake through the diet is equal to loss through urine and feces. Nonessential amino acids can be formed by transamination, which is the transfer of the amino group (-nh2) from one amino acid to a different keto acid to form another amino acid.