General Knowledge!

[BFM_Edison]

All I have to say is nom nom nom buckyballs.

[MrMxyzptlk]

Keeping the chemistry 101 questions...
What is an isomer?

Compounds with the same molecular formula, but different structural formulas.

I was always fascinated by cis-trans isomers and had high hopes for "left-handed sugar" when they first made some....

[BFM_Fénix]

All I have to say is nom nom nom buckyballs.

LOL I thought something similar after 360's question!!!

Keeping the chemistry 101 questions...
What is an isomer?

Compounds with the same molecular formula, but different structural formulas.

I was always fascinated by cis-trans isomers and had high hopes for "left-handed sugar" when they first made some....

That isomer of sugar would be quite useless in the metabolic point of view, except for dietary purposes (are you trying to lose a few pounds Mxy??? ). Considering the specificity of the enzymes involved in glycolisis, that L-isomer is unable to be used to obtain pyruvic acid and, as consequence, the Krebs cycle can't occur (shame).

However, that was not the point of my question so...

GO MXY GO!

[MrMxyzptlk]

Yes, left-handed sugar was inert to the human body, except that it turned out the the receptors on the human tongue did react correctly, so things tasted sweet, but had ZERO calories!  (And I was thinking for "Obese America" not only my own sweet tooth!    )

Meh, all the other chemicals would probably find a way to kill us instead.... 


Next up:

Household science! (Yes, I cook and bake!)


How many teaspoons in a cup? (US measures, sorry!)

[BFM_Fénix]

Yes, left-handed sugar was inert to the human body, except that it turned out the the receptors on the human tongue did react correctly, so things tasted sweet, but had ZERO calories!  (And I was thinking for "Obese America" not only my own sweet tooth!    )

Well, considering obesity among children México has the non-honorable first place worldwide, it would be a problem for both .

BTW, I see a typo there... I IZ DIZAPOINTEDDD 

Now, teaspoons... I'd say 2 since I have absolutely no idea.

[BFM_Kiwi]

About 3 teaspoons in a tablespoon I think.  I think 3 tablespoons would be 1/4 cup.  So 3 x 3 x 4 = 36?

[BFM_Xtr3me]

About 3 teaspoons in a tablespoon I think.  I think 3 tablespoons would be 1/4 cup.  So 3 x 3 x 4 = 36?

actually, i think 4 tablespoons are in a 1/4 cup,
so im gonna go for

3 x 4 x 4 = 48

[TUR80]

42

[MrMxyzptlk]

BFM_Xtr3me got it spot on! 



...And no, bfm_TUR80, I was not asking for "the answer to life, the universe, and everything!" 


Your turn, BFM_Xtr3me!

[TUR80]

lol
i just guessed in the middle
didnt even realise

[jim360]

What's the difference between L-sugar and... a sugar molecule that you're looking at from the other side?

[BFM_Xtr3me]

What are the top 10 most spoken languages in the world? (who ever answers the most goes next ;p)
Extra cookie if you order them correctly

[BFM_JANE]

Chinese
English
Whatever they speak in India (Hindi? I'm stupid, forgive me!)
Spanish
German
French
Japanese
Cantonese
Tagalog

And that's all I can think of. There are probably some Asian languages that are very popular, Cantonese or Tagalog, but I have no I idea. I'll just add them now

[gamepanther]

Chinese
English
Whatever they speak in India (Hindi? I'm stupid, forgive me!)
Spanish
German
French
Japanese
Cantonese
Tagalog

And that's all I can think of. There are probably some Asian languages that are very popular, Cantonese or Tagalog, but I have no I idea. I'll just add them now

1. Chinese
2. English
3. Hindu
4. Spanish
5. Russian
6. Arabic
7. Bengali
8. Portuguese
9. Malay
10. French

  We did this in Geography yesterday (Please don't blame me if I am wrong, I am only remembering off the top of my head)

         ~BFM_Panther

[BFM_Fénix]

So... Should we believe Jane is next?

What's the difference between L-sugar and... a sugar molecule that you're looking at from the other side?

I understand why this question is oftenly asked. Considering this kind of representation of a molecule I would consider it is just seeing the same molecule from another point of view.



First of all, an L sugar is an enantiomer (mirror image) of the D sugar (L-Glucose and D-Glucose in the image). Optically, we would consider that changing the view of the L-Glucose would give the D-Glucose, but that's not the case. We have to (must) consider the spatial organization of atoms within a molecule.

In a molecule, each type of bond require an amount of space to stabilize the bonding of the atom. What I mean is: every valence electron that participates in a bond require a space according to the type of bonding (typically in C compounds, there are n, pi and sigma bonds depending if there is a single, double or triple bond) and, as consequence, all valence electrons distribute the space proportionally. For example a Carbon with 4 single bonds will have two bonds to the side, 1 pointing to the front and 1 to the back. Obviously this example is subdued to change if you change the point of view, but what I mean is 2 bonds are in the same plane.

Now, going back to the L sugar... Consider the next image with the D-molecule to the left and the L-molecule to the rigth (NOTE: this applies to all enantiomers):



As you can see in the image, the H, NH2, CH3 and COOH parting from the chiral carbon (central carbon in this case) mantain their respective bond representation (a black triangle represents a bond pointing to the front and the pointed line to the back). Now, if you change the point of view of the L-molecule as to overlap the position of H, NH2, CH3 and COOH of the D-molecule (seeing the L-molecule from behind), you would notice that, even though the functional groups are now in the "same" place, the spatial orientation of the NH2, CH3 and COOH is different (D-molecule has CH3 to the front and NH2 and COOH to the back while L-molecule is opposite).

I hope I could explain myself as to clarify any doubt about D and L molecules...  

EDIT: GAH! I hate Wikipedia and its .svg images...