## ratio of product / reactant

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### ratio of product / reactant

Hello Everyone.

I'm stuck on a few questions. But since they are long, I will post one at a time. I'm just working on a study workbook that was recommended for my biology class, but i can only get half way done the problems. I hope you can help.

1. For the reaction:

dihydroxyacetone phosphate <----> glyceraldehyde 3-phosphate

Delta G' = 1.8kcal/mol (I'll use this symbol ^ for delta)

What ratio of product/reactant must be maintained in order to keep the rxn going in a forward direction?

So this is what I've got so far ( and the back of the book shows the answer, but it doesnt show all the steps so it loses me near the end)

^G' < 0

^G' + 2.303 RT Log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < 0

1.8 kcal = 1800 cal

1800 cal/mol + (2.303) (1.987cal/mol K) (298K) log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < 0

1364 Log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < -1800cal/mol

Log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < -1800 / 1364

Log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < -1.32cal/mol

Then from here I dont know how to get rid of "log"

The final answer says it should be

(glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < 0.048 cal/mol

How did it go from -1.32 cal to 0.048 cal

Please help.

I'm stuck on a few questions. But since they are long, I will post one at a time. I'm just working on a study workbook that was recommended for my biology class, but i can only get half way done the problems. I hope you can help.

1. For the reaction:

dihydroxyacetone phosphate <----> glyceraldehyde 3-phosphate

Delta G' = 1.8kcal/mol (I'll use this symbol ^ for delta)

What ratio of product/reactant must be maintained in order to keep the rxn going in a forward direction?

So this is what I've got so far ( and the back of the book shows the answer, but it doesnt show all the steps so it loses me near the end)

^G' < 0

^G' + 2.303 RT Log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < 0

1.8 kcal = 1800 cal

1800 cal/mol + (2.303) (1.987cal/mol K) (298K) log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < 0

1364 Log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < -1800cal/mol

Log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < -1800 / 1364

Log (glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < -1.32cal/mol

Then from here I dont know how to get rid of "log"

The final answer says it should be

(glyceraldehyde 3-phosphate) / (dihydroxyacetone phoshate) < 0.048 cal/mol

How did it go from -1.32 cal to 0.048 cal

Please help.

LOL, that's all what you need? Just convert logarithm to normal number?

log (10^x) = x

^ here means power, so you can have like:

log 100 = log (10^2) = 2

pretty simple, isn't it?

(of course, this is decimal logarithm, but the basis can be any)

log (10^x) = x

^ here means power, so you can have like:

log 100 = log (10^2) = 2

pretty simple, isn't it?

(of course, this is decimal logarithm, but the basis can be any)

http://www.biolib.cz/en/main/

*Cis*or*trans*? That's what matters.Log is a logarithm:

explanation in wikipedia: http://en.wikipedia.org/wiki/Logarithm

basic maths skills are useful in biology, you know?

explanation in wikipedia: http://en.wikipedia.org/wiki/Logarithm

basic maths skills are useful in biology, you know?

Patrick

Science has proof without any certainty. Creationists have certainty without

any proof. (Ashley Montague)

Science has proof without any certainty. Creationists have certainty without

any proof. (Ashley Montague)

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