Invert Sugar

[pbh4]

FINMAN: "As a biochemist I can say the bees does not need inverted sugar. It is so simple"

You keep saying this and yes they can invert the sugar with gut enzymes BUT it is at a metabolic cost to them to do so.

I think you are wrong, greengumbo. According to various sources the change in Gibbs free energy for the reaction

sucrose+water->glucose+fructose​

is -29.3 KJ/mole. In other words the reaction will happen spontaneously and there is NO metabolic cost to the bees (apart from the cost of making a tiny bit of enzyme which they probably add to whatever they eat anyway). There is an energy barrier that usually prevents the reaction from occurring spontaneously and the role of the invertase is merely to provide a route around the energy barrier. Once added to the sucrose the reaction just happens with no effort from the bees.

The reaction is also exothermic (the change in enthalpy is about -15 kJ/mole) so it warms the hive and in fact saves the bees the effort of heating. It is a metabolic credit not a cost.

Is that right Finman? My chemistry is a bit rusty.

If "we" do the work for them by supplying inverted sugar then they do not incur this metabolic cost.

Now i'm just a lowly 1 hive owner (and its barely going!) but that is just simple entropy.

Entropy is not at all simple but it is accounted for by the Gibbs free energy.

Paul

 

[Finman]

The reaction is also exothermic (the change in enthalpy is about -15 kJ/mole) so it warms the hive and in fact saves the bees the effort of heating. It is a metabolic credit not a cost.

Is that right Finman? My chemistry is a bit rusty.


Paul

that goes over normal instincts....

When bees handle syrup and cap it, they use 24% out of syrup energy in the process.
They ventilate that atively out and dry up the syrup.

And when we look your mesh floors, noninsulated hives and open feeding holes, match sticks
i think that that enthalpy is a thing which saves you hives in wintering. And let's do not forget added feeding which starts before Christmas.

 

[greengumbo]

I think you are wrong, greengumbo. According to various sources the change in Gibbs free energy for the reaction

sucrose+water->glucose+fructose​

is -29.3 KJ/mole. In other words the reaction will happen spontaneously and there is NO metabolic cost to the bees (apart from the cost of making a tiny bit of enzyme which they probably add to whatever they eat anyway). There is an energy barrier that usually prevents the reaction from occurring spontaneously and the role of the invertase is merely to provide a route around the energy barrier. Once added to the sucrose the reaction just happens with no effort from the bees.

The reaction is also exothermic (the change in enthalpy is about -15 kJ/mole) so it warms the hive and in fact saves the bees the effort of heating. It is a metabolic credit not a cost.

Is that right Finman? My chemistry is a bit rusty.



Entropy is not at all simple but it is accounted for by the Gibbs free energy.

Paul

Is this not assuming 100% efficiency of the reaction ? I know that the manufacture of detoxification enzymes is a significant metabolic cost to insects, hence why resistance mechanisms often disappear from populations after the insecticide or toxin is removed. So I'm not sure that saying the manufacture of invertase and other dietary enzymes is insignificant is true.
Interesting stuff !

 

[farbee]

I think you are wrong, greengumbo. According to various sources the change in Gibbs free energy for the reaction

sucrose+water->glucose+fructose​

is -29.3 KJ/mole. In other words the reaction will happen spontaneously and there is NO metabolic cost to the bees (apart from the cost of making a tiny bit of enzyme which they probably add to whatever they eat anyway). There is an energy barrier that usually prevents the reaction from occurring spontaneously and the role of the invertase is merely to provide a route around the energy barrier. Once added to the sucrose the reaction just happens with no effort from the bees.

The reaction is also exothermic (the change in enthalpy is about -15 kJ/mole) so it warms the hive and in fact saves the bees the effort of heating. It is a metabolic credit not a cost.

Is that right Finman? My chemistry is a bit rusty.



Entropy is not at all simple but it is accounted for by the Gibbs free energy.

Paul

Gibbs free energy is temperature dependent and so you have to quote at what temperature. However as this reaction has an increase in entropy (one molecule forms two molecules) and it is exothermic so will be feasible/spontaneous under all conditions (assuming your values are correct). Probably more complex than this in reality though.

I notice Finman did not answer
Wonder why?