What is Protein Metabolism?

What is Protein Metabolism?

Within the human body, muscles, as well as organs like the heart, liver, and kidneys, and even structures like bones and teeth, contain abundant proteins. Apart from water, proteins constitute about 80% of the cell's substance. Comprising various amino acids, proteins serve pivotal roles in the human body. They participate in the construction, repair, and resynthesis of cellular components to facilitate self-renewal. Proteins are also involved in the synthesis of biologically active substances such as enzymes and hormones. They function as energy sources, maintain fluid and acid-base balance, and contribute to various physiological processes.

Diet constitutes the primary source of proteins. Once ingested, food undergoes digestion in the digestive tract, breaking down into amino acids under the action of digestive fluids, which are subsequently absorbed by the small intestine. Almost all absorbed amino acids enter the bloodstream through capillaries and can be resynthesized into proteins in various tissues. Following metabolic processes such as deamination, amino acids eventually generate ammonia, carbon dioxide, and water.

Water, the essence of life, is a crucial component of human cells and bodily fluids, accounting for around 60% to 70% of body weight. Water is indispensable for numerous physiological activities within the body. It plays irreplaceable roles, directly or indirectly transporting oxygen and various nutrients to tissues and organs, as well as promptly excreting metabolic waste and harmful substances through urine, sweat, respiration, and other pathways. During physical training, when the body generates more heat, water dissipates heat through sweat evaporation, effectively preventing the occurrence of overheating.

Within human tissues, apart from carbon, hydrogen, oxygen, and nitrogen—elements that primarily exist in organic compounds—other elements are collectively referred to as "inorganic salts," also known as "minerals." Inorganic salts play crucial roles in numerous biochemical processes within the human body. They participate in forming body tissues, regulating physiological functions, and maintaining normal metabolism.