Collagen occurs extensively in nature.
It is the most common fibrous protein found in the organic and physical structure of the vertebrates; that is, birds, reptiles, fish and mammals, including humans.
Collagen is the basic structure of all the skin, tendon, bone, membrane and connective tissue in our bodies and in the bodies of those creatures. Collagen is thus the structural protein of the animal kingdom and that of humans. It is to humankind and to animals to what cellulose is to plants.
There are no plant sources of collagen.
As gelatin is derived from collagen, it follows that there are no plant source of gelatin either. Thus, there is no chemical relationship between gelatin and other materials often referred to as ‘vegetable gelatins’, such as seaweed extracts or gums like carrageen or guar.