An infection or the products of infection carried throughout the body by the blood is called:

An infection or the products of infection carried throughout the body by the blood are called blood borne pathogens. These are infectious microorganisms can cause diseases in humans. Examples of this is hepatitis B (HBV) and human immunodeficiency virus or also known as HIV.

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.