| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 3771.1 | Two possibilities | VMSMKT::KENAH | There are no mistakes in Love... | Wed Mar 24 1993 10:45 | 3 |
| Try a pharmacy, or a chemical supply house.
andrew
|
| 3771.2 | | VERGA::CIAMPAGLIA | | Wed Mar 24 1993 10:55 | 1 |
| Or try a store that sells natural foods.
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| 3771.3 | More information about dextrose | VMSMKT::KENAH | There are no mistakes in Love... | Wed Mar 24 1993 10:56 | 11 |
| Dextrose is a kind of sugar. It is a monosaccharide, (C)6(H)12(O)6
Dextrose is an isomer of levulose; that is, it has the same chemical
formula, but different chemical and physical properites due to a
difference in the arrangement of the atoms in the compound.
Dextrose is, in fact, a mirror image of levulose. Levulose is the
chemical name for fructose (fruit sugar).
Sucrose (common cane or beet sugar) is a disaccharide; it can be broken
down (by hydrolysis) into dextrose and levulose.
|
| 3771.4 | Let me guess... | KAOFS::M_FETT | alias Mrs.Barney | Wed Mar 24 1993 15:01 | 4 |
| Could it be that dextrose is the "right-handed" version of levulose?
(Dexter = right?) 8-)
Monica
|
| 3771.5 | | ADSERV::PW::WINALSKI | Careful with that AXP, Eugene | Wed Mar 24 1993 20:39 | 46 |
| RE: .3
Dextrose and levulose are not mirror images, nor are they stereoisomers.
Dextrose is a common name for D-glucose and levulose a common name for
D-fructose. The names derive from the fact that glucose solutions rotate
polarized light in a clockwise (dextro-, to the right) direction, while
fructose rotates polarized light in a counterclockwise (levo-, to the left)
direction. They both have the same empirical chemical formula (C6H12O6), but
they are structurally different: glucose is an aldehyde while fructose is a
ketone:
D-glucose D-fructose
HC=O H2COH
| |
HCOH HC=O
| |
HCOH HCOH
| |
HCOH HCOH
| |
HCOH HCOH
| |
H2COH H2COH
(the above diagrams aren't completely correct, in that they don't show the
correct stereoisomeric orientation of the H- and -OH groups around carbons 2-5)
Note also that both glucose and fructose (as well as nearly all other commonly
encountered sugars) are part of the D- stereoisomeric series (which is
determined based on the configuration relative to that of glyceraldehyde, and
is biologically significant, whereas the way that solutions rotate polarized
light has no biochemical significance).
Sucrose is D-glucopyranosyl D-fructofuranose. It consists of one molecule of
glucose (in a 6-membered hemiacetal ring formed by joining carbon 5 to the
aldehyde oxygen at carbon 1) and one molecule of fructose (in a 5-membered
hemiketal ring formed by joining carbon 5 to the ketone oxygen at carbon 2),
joined together in a glycosidic (ether) linkage.
The 50:50 mixture of glucose and fructose obtained by hydrolysis of sucrose is
commonly known as "invert sugar" because it rotates light in the opposite
direction as does sucrose. "Invert sugar" sometimes shows up as an
ingredient on food labels. "Invert sugar" (50:50 glucose and fructose) is not
to be confused with "levulose" (synonym for fructose).
--PSW
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| 3771.6 | ex | DNEAST::MAHANEY_MIKE | | Thu Mar 25 1993 03:52 | 7 |
| Thanks for all of the replies. Now if the clerk ask me what it
is I am actually looking for I WILL be able to tell them!!
Mike
|
| 3771.7 | | VMSMKT::KENAH | There are no mistakes in Love... | Thu Mar 25 1993 17:19 | 3 |
| Paul:
Thanks for the clarification and expansion...
|