What is the difference in sugars-used-for-respiration concentration in 100ml 2% glucose solution, 100ml 2% sucrose solution and a 100ml 2% starch solution?

Question

frostbite · Answer

Mind to elaborate a bit?

frostbite · Answer

You just want structural difference in the carbohydrates or something else?

anonymous · Answer

The amount of monosaccharides in each solution please.

frostbite · Answer

Okay lets assume we got a mass concentration, we can then write for the first glucose solution:
$$\Large n(C_{6}H_{12}O_{6})=\rho \times M^{-1}$$
Our mass concentration $\rho$ will take the form
$$\Large \rho = \frac{ 2 g ~ C_{6}H_{12}O_{6} }{ 100 ml }$$
Try calculate the amount of substance.

frostbite · Answer

$M$ is in this case the molar mass.

frostbite · Answer

You know how to calculate $n(C_{6}H_{12}O_{6})$?

anonymous · Answer

Yes.

anonymous · Answer

Around 0.011111mol of glucose?

frostbite · Answer

Looks about right.
Okay that is the concentration of glucose, which is a monosaccharide.
Lets continue to sucrose, same procedure as before, but what is the structural difference between glucose and sucrose we gotta include in this calculation?

anonymous · Answer

Sucrose is a disaccharide so its 0.058mol times by 2?

frostbite · Answer

Exactly.

anonymous · Answer

And starch is a polymer so obviously it would have more sugar in that right?

frostbite · Answer

Correct, well done! Solved your own problem without help almost :)

anonymous · Answer

So in terms of cellular respiration, which solution would cells produce the most CO2 from?

anonymous · Answer

It would be the starch solution wouldn't it? Or am I not taking into account other factors?

frostbite · Answer

That is correct, the amount of $\sf CO_{2}$ is proportional with the amount of sugar with the proportionality constant equal to 6. (assuming all the sugar is used for respiration)

anonymous · Answer

Thank you!

frostbite · Answer

No problem at all.