In most organisms, the living material contains 80% of proteins. Proteins are large, complex molecules that are essential for the structure, function, and regulation of cells and tissues in living organisms. They are composed of chains of amino acids, which are linked together by peptide bonds.

Proteins are involved in a wide range of biological processes. They play a crucial role in the growth and development of organisms, as they are necessary for the formation of new cells and tissues. Proteins also act as enzymes, which are catalysts that speed up chemical reactions in the body. Additionally, proteins are involved in the transportation of molecules within cells, the regulation of gene expression, and the defense against pathogens.

Proteins are found in all living organisms, from bacteria to plants to animals. They are particularly abundant in animal tissues, where they make up a significant portion of the body's mass. In fact, approximately 15-20% of a person's body weight is composed of proteins.

Proteins are made up of different combinations of amino acids, which are organic compounds that contain an amino group (-NH2) and a carboxyl group (-COOH). There are 20 different amino acids that can be combined in various ways to form different proteins. The sequence and arrangement of amino acids determine the structure and function of the protein.

Proteins can be obtained from dietary sources, such as meat, fish, eggs, dairy products, and legumes. When we consume protein-rich foods, our body breaks down the proteins into amino acids, which are then used to build and repair tissues, produce enzymes and hormones, and perform other essential functions.

In conclusion, proteins are a vital component of living organisms, comprising 80% of the living material in most organisms. They are involved in various biological processes and play a crucial role in the structure, function, and regulation of cells and tissues.