Which is the best definition of activation energy? the energy required to end a chemical reactionthe energy required to bind a substrate to an active site the energy required to break the bonds of reactant molecules the energy required to re-form bonds in product molecules

15 ! come and answer! a(n) is the general term for an infectious disease that has spread across a city, region, or country.

This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web. a) bacteria and fungi, the decomposers, recycle carbon from dead organisms. b) carbon is found in the grass and is passed from one level to the next in this food web. eliminate c) all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere. d) plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.

This is the nitrogenous base only found in rna