Hello Rick,

I like to comment on your question why are nectaries excrete sucrose?

First of all, not all nectaries secrete sucrose, other sugars,
expecially glucose and fructose are excreted by differennt plants and
even the ration of glucose to fructose is not always in the ratio of
1:1 as would be expected from sucrose, which is composed of one
glucose and one fructose.

So why is sucrose the preferre sugar? This has to do with the
stability of either glucose ore fructose in solution. Glucose at C1 in
the partly oxidized form of an aldehyde and Fructose has en keto-group
on C2. Thus both forms are less stabel as the combined sugars in
sucrose where both groups are masked in an alpha-1-beta-two-binding,
which is more stable. This is also the reason why the transported form
of sugares in the plant ins mainly sucrose.

Best regards,

 Ahlert Schmidt (Botanist) mailto:[log in to unmask]