noun. 1  a mutation occurring in a somatic cell, resulting in a change in the morphology or some other aspect of one part of an organism (usually a plant). 2  It may be maintained by vegetative propagation but not by sexual reproduction.oun. 1  a mutation occurring in a somatic cell, resulting in a change in the morphology or some other aspect of one part of an organism (usually a plant). 2  It may be maintained by vegetative propagation but not by sexual reproduction.
Protein has a range of essential functions in the body, including the following: 1  Required for building and repair of body tissues (including muscle). 2  Enzymes, hormones, and many immune molecules are proteins. 3  Essential body processes such as water balancing, nutrient transport, and muscle contractions require protein to function. 4  Protein is a 5  ... P Enzymes, hormones, and many immune molecules are proteins. 2  Essential body processes such as water balancing, nutrient transport, and muscle contractions require protein to function. 3  Protein is a source of energy. 4  Protein helps keep skin, hair, and nails healthy.
Types and Functions of Proteins. Proteins perform essential functions throughout the systems of the human body. These long chains of amino acids are critically important for: catalyzing chemical reactions. synthesizing and repairing DNA. transporting materials across the cell. receiving and sending chemical signals.