Final answer:
The carbons of ribose involved in ring formation are C-1' and C-4', which create a furanose ring when they form a hemiacetal.
Step-by-step explanation:
The carbons of ribose that are involved in the ribose ring formation are C-1' and C-4'. When these two carbons react, they form a hemiacetal, which results in the creation of a five-membered ring structure known as a furanose ring. This is because the ribose sugar in RNA has a hydroxyl (-OH) group at the anomeric carbon (C-1') that points towards the oxygen in the ring and creates a beta configuration. On the other hand, deoxyribose lacks the hydroxyl group at C-2', which is why DNA contains deoxyribose—which stands for the removal of an oxygen atom.