The only proven effect of radio waves on biological tissue is to heat it up. So yeah it's possible to alter chemical reactions in biological tissue by changing the temperature but radio waves would be an incredibly inefficient way of doing that.
Also please mind your tone. Asking for examples of what you mean is a necessary step to answering the question in a meaningful manner.
A major area of research in biology is figuring out how to control the activity of proteins using visible light. This field, called optogenetics, involves finding/engineering proteins that respond to light and using them to control various biological processes. Most of the effort in this field has been on using light-sensitive ion channels (e.g. channelrhodopsin) to control the activity of neurons, but some groups have developed optogenetic means to control the activity of enzymes. Some of these studies control enzyme activity indirectly by using a pair of proteins whose interaction is dependent on light (for example, see Levskaya et al 2009. Spatiotemporal control of cell signalling using a light-switchable protein interaction. Nature 461: 997 http://dx.doi.org/10.1038/nature08446 [Broken]), while others engineer enzymes whose activity is more directly controlled by light (for example, see Wu et al 2009 A genetically encoded photoactivatable Rac controls the motility of living cells. Nature 461: 104 http://dx.doi.org/10.1038/nature08241 [Broken]).
Currently, optogenetic approaches work only for visible light (for an explanation why see this post). I do not know of any approaches to control the activity of biological molecules using rf radiation.