I am not experienced in the topic, and could not find any article related to these kind of reactions, but my guess is the following. During the nuclear transmutation the radiocarbon will lose an electron (beta particle), so the nitrogen product will have positive charge. After that there are 2 possible scenarios.
a.) less plausible scenario
The beta particle carries away the energy of the decay, so the molecule will have low energy and it will be able to rearrange.
The electron shells will collapse a little bit, since the nitrogen has smaller nuclear radius. The part after that depends on which carbon we are talking about in the glucose molecule. I would guess the following rearrangements:
- ${-CH2OH} \rightarrow {-NHOH} + H^+ $
- ${=CHOH} \rightarrow {=NH} + H^+ $
- ${-CHO} \rightarrow {-NO} + H^+ $
It is not easier to break an N-H bond compared to the N-C and N-O bonds according to this table, but I think what really matters here is the stability of the final product, and $H^+$ is way more stable than any $^+O*$, $^+C*$, etc. ion.
b.) what really happens
The beta particle carries away the energy of the decay only partially. So the nitrogen will have a lot of energy, which is more than enough to break all of the bonds. According to wikipedia the decay energy is . Let's compare this with the bond energies:
$ 0.156476 MeV = 2.50702189 \cdot 10^{-17} kJ $
${2.51 \cdot 10^{-17} kJ} \cdot {6 \cdot 10^{23} \cdot 1/mol} = 1.51 \cdot 10^7 kJ/mol$
According to our table the covalent bonds have about a few hundred kJ/mol energy, e.g. a C-N bond has 305 kJ/mol energy. So it is very likely that the chemical bonds will break immediately after the decay and the molecule will fall apart.