Fructose metabolism pathway..help!

Question

alright i did this in the test..i srewed it up!

fructose catabolism as usual is fructose degraded by fructosekinase than the question ask that it is converted into a triaclyglycerol!

this is what i did, as supposed to what my friends did, where they enter it into the glycolysis pathway

the end product of fructose catabolism, glyceraldehyde 3-p i insert it into the gluconeogenesis pathway to make glucose..

and with glucose i link it to triacylglycerol pathway where..(i hope this helps u picture)

glucose>dihydroxyacteone-p>glycerol 3-p> phosphatide> diacylglycerol> triaclyglycerol

sigh thats wat i did..

tis is wat my friends did, after the fructose pathway, they get pyruvate. pyruvate then into

pyruvate>acetyl coa and oxaloacetate>condense into citrate> and the adding of malonyl coa and acetyl coa onto the fatty acids synthase

sigh!! so which one is right

Answer 1

hey I'm studying bio now.. although I'm not very sure of the answer, but the second option seems to be more correct. yep

Answer 2

Fructose can be handled two ways . At low concentrations of fructose , the enzyme hexokinase convertes fructose to fructose - 6-phosphate the same compound that is produced via isomerization from glucose -6- phosphate in the glycolytic pathway strating with glucose .  At higher concentrations , fructokinase ( whiich has a higher Km for fructose than hexokinase ) in the liver converts fructose to fructose 1-phosphate which is cleaved by aldolase b to produce dihydroxyacetone phosphate and glyceraldehyde . the glyceraldehyde can be converted to glyceradehyde 3 -phosphate by a kinase and the pathway looks the same as normal glycolysis. However...the action of aldolaseb on fructose -1 P comes in below the rate limiting and highly regulated enzyme phosphofructokinase ( that converts fructose-6 phosphate to fructose, 1 6 bis phosphate . This means that the high levels of fructose metabolized via this route will swamp the normal glucose metabolisn pathways ( no regulation by PFK ) and thus cause fat deposition, increased glycogen storage and enhanced blood glucose ( not a great option for diabetics ). So low to minimal /moderate levels ok