World hunger is a terrible symptom of world poverty. If efforts are only directed at providing food, or improving food production or distribution, then the structural root causes that create hunger, poverty and dependency would still remain. 1 billion children live in poverty (1 in 2 children in the world). 2  640 million live without adequate shelter, 400 million have no access to safe water, 270 million have no access to health services. 10.6 million died in 2003 before they reached the age of 5 (or roughly 29,000 children per day).
A catalyst is a substance which speeds up a reaction, but is chemically unchanged at the end of the reaction. When the reaction has finished, you would have exactly the same mass of catalyst as you had at the beginning.
Enzymes are very efficient catalysts for biochemical reactions. They speed up reactions by providing an alternative reaction pathway of lower activation energy. Reaction profiles: uncatalysed and enzyme-catalysed. Like all catalysts, enzymes take part in the reaction - that is how they provide an alternative reaction pathway. But they do not undergo permanent changes and so remain unchanged at the end of the reaction.