# Photosynthesis Conversion - (Aug/01/2007 )

Hello, I 'm looking for a formula for converting microlitres of oxygen produced at a rate gram per minute TO micro-mole Carbon Dioxide taken in per square meter of leaf per second.

(ul O2 g^-1/min to uM CO2 m^-2/g

Would really appreciate it.

Thanks

-ForeverUNDERGRAD-

QUOTE (ForeverUNDERGRAD @ Aug 1 2007, 04:09 AM)

Hello, I 'm looking for a formula for converting microlitres of oxygen produced at a rate gram per minute TO micro-mole Carbon Dioxide taken in per square meter of leaf per second.

(ul O2 g^-1/min to uM CO2 m^-2/g

Would really appreciate it.

Thanks

(ul O2 g^-1/min to uM CO2 m^-2/g

Would really appreciate it.

Thanks

well, first of all you haven't really provided all the info so I could figure it out, but you want to figure it out on your own anyways, so I will do what I can with what you have provided.

There s no one formula to answer your question, you have to look at the net reaction for photosynthesis, which is: l

light + CO2 + H2O --> O2 + CH2O

so all you need to do is understand the stoichiometry, there is one mole of CO2 used for one mole O2 produced,

WHat you should do is play around with the ratios you know- You were probably given an amount of O2, or plant material, lets say you start with amount of O2:

(1/ X amount of O2) * (1 gram O2 produced/minute)*(1 miunte/60 sec)* (1 mol O2/15.99 g O2)* (1 mole CO2/ 1 mole O2)

This leaves you = X mol CO2/sec

Now comes to the part where you are missing information:

Were you given how much plant material?

Or maybe you will need density of O2 gas:

1.4 kg/cubic meter

and

1 cubic centimeter = 1 mL

You should write down everything you know units and all, then exactly what you are looking for. If you were given volume of O2 gas, start with that and manipulate the stoichiometric ratios- CANCEL OUT units you dont want until you have the ones you do.

I hope you can figure this out.

-Vicky.ac-

Vicky.ac thank you! I'll get to work on it, sadly its early hours of the morning here but thanks again I really really appreciate your help

-ForeverUNDERGRAD-

Wow, I am really sucking at this, I must be overlooking something. Other values, I evolved 21ul of oxygen in a period of 5 minutes at 21 PAR, the weight of the shoot after the duration was 3.02g, I calculated the photosynthetic rate to be 1.390728477.

The SLA of the light plant is 17cm2g-1

The SLA of the shade plant is 20cm2g-1

Thanks again.

-ForeverUNDERGRAD-