what are ribozymes?

Answer 1

Enzymes are essential agents in living systems that catalyze four of the biochemical reactions with extraordinary speed and precision. Although enzymes made of protein are the dominant form of biocatalyst in modern cells, there are at least eight natural RNA enzymes, or ribozymes, that catalyze fundamental biological processes. It is believe that these ribozymes might be the remnants of an ancient form of life that was guided entirely by RNA.

Answer 2

Wikipedia

Answer 3

Ribozyme is an RNA molecule that is capable of catalyzing a chemical reaction. Usually proteins do that, however some RNAs can do it, too - they usually participate in modification of other RNA molecules (like excision of introns - for example there are some RNAs that can excise their own introns without help of proteins). This has led to the theory that RNA was the initial molecule of inheritance, not DNA.

Answer 4

RNA catalysts. Most biological reactions are catalyzed by proteins, but some are catalyzed by RNAs. Catalysts speed up the reaction without being consumed by it. Because RNA is a catalyst and apparently DNA is not, there is speculation that RNA was the first biomolecule at the origin of life ("RNA WORLD" theory) and there was an RNA universe allowing both inheritance and catalysis. Later, the DNA was specialized for the inheritance and proteins for the catalysis, leaving most RNA as an assistant in protein manufacture.

Answer 5

Google is your friend

http://en.wikipedia.org/wiki/Ribozyme