1
Pyrimidines have a single ring in their molecule.
A pyrimidine ring and an imidazole ring.
Pyrimidines have a single ring and are part of the basic building blocks for RNA and DNA.
four rings
Pepper - as all the vegetables is a complex of many compounds; consequently no moleculear structure of pepper. Only a chemical substance has a molecular structure.
Sugar = Sucrose = C12(H2O)11 or C12H22O11 The general category of "sugar molecules" contains two divisions: sugars made of five carbon rings and sugars made of six carbon rings. Then there are different functional groups attached to the rings and the rings may be linked together to form disaccharides (such as sucrose) or polysaccharides.
Oliver Hanson
Their chemical and molecular structure is such that microbes and bacteria can not break them down. They have very high molecular weight.
2
Steroid hormone usually contain five ring structures.
I can give you several sentences.The molecular number of an element helps you to identify it.We studied the molecular structure of many common elements.Using an electron microscope, you can see down to the molecular level.
there are double rings in the purine bases and there is only a single ring in the pyrimidine base.