D and L isomers of monosachrides

[Mjhavok]

What are the nutritional and health implications of using D and L isomers of monosaccharides.

[Trev]

I believe, it`s not important. Because our ferments cut only bonds. D and L - are only orientation of molecules.

[Ultrashogun]

I think L sugars wouldnt work due to stereospecifity of enzyms.

[victor]

I think L sugars wouldnt work due to stereospecifity of enzyms.

Yup, you got it right shogun....our sugar hydrolysis enzymes are stereospecific to it's substrate which is D-glucose. And usually, sugar like glucose are oftenly in it's natural form which is in D-form. Beside, our tongue also has a stereospecific pappilae which interprate 'sweet' as we taste D-glucose and interpretate 'bitter' as we taste L-glucose...

I you wanna know more about sugar (generally carbohydrate), I suggest you better hurry get your organic chemistry book and open stereochemistry chapter....(that's or the beginning.. )

[Ultrashogun]

Is there any harm in ingesting L-isomers?

I ask that because I read somewhere, that many pharmacological substances, advil for example, are actually racemic and that not only is one isomer not active, but also inhibits and thus delays the effect by some time.

Im thinking this because you say that L sugars taste bitter, and bitter is usually a taste which would cause an animal to stop consumption.

[Mjhavok]

For instance the enzyme permease I have read is very stereospecific.

Thanks for the input guys.

[victor]

what we consume is sucrose isn't it? and we know that sucroce is racemic, so, there's no bitter taste or anything..