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.
Cell membrane proteins have a number of different functions. Structural proteins help to give the cell support and shape. Cell membrane receptor proteins help cells communicate with their external environment through the use of hormones, neurotransmitters, and other signaling molecules. Transport proteins, such as globular proteins, transport molecules across cell membranes through facilitated diffusion.