Collagen is secreted by fibroblasts. Some type of collagen are also secreted by epithelial cells. There are different types of collagen in the body.
Collagen is the most abundant protein in the body and a key components of all connective tissues. It provides the infrastructure of the muscoskeletal system which are essential for mobility.
If you add the amount of protons with the amount of neutrons, you get the atomic mass. Sodium has 11 protons, and 12 neutrons. 11+12=23
The operon is effectively the center of transcriptional control. In addition to its main structural genes, the operon houses an operator and a promoter. In front of the promoter lies a regulatory gene that produces repressor proteins. When a repressor is in its active state, it binds to the operator.
Hope this helped.
