CHEMICAL STRUCTURE AS DEPECTED BY STICK PICTURES WHAT DO THOSE LINES MEAN?

Organic chemistry has a symbolic method for drawing molocules that is a shortcut for representing what the molocule looks like. A simple molocule called ethane will serve as an example. It has a formula of 2 carbon atoms and 6 hyrogen atoms, or C2H6.

The twp carbon atoms are bonded together by what is called a single bond which is represented by a single line drawn between the two carbon atoms.

C-C

Each carbon atom also has 3 hydrogen atoms bonded to it by single bonds.

  H H
  | |
H-C-C-H
  | |
  H H

But in the shorthand symbol the first step is to leave out the hydrogen atoms because any good chemist will understand they are present by implication. The rule is any carbon atom will always have 4 bonds, and if any of those four possible bonds is missing from the stick structure it is implyed that the missing bond is due to an undrawn hydrogen atom bonded the the carbon atom.

The next step is to leave out the C that represents the carbon atom but leave the stick that is the representation of the bond. So what is left for the ethane molocule is a single line.

-

Extending that to a molocule that has four carbon atoms bonded together by single bonds gives

- - -

which means

C-C-C-C

and adding in any hydrogen atoms so each carbon atom has four bonds gives

  H H H H
  | | | |
H-C-C-C-C-H
  | | | |
  H H H H
And finally recognising that carbons atoms really don't all line up in a nice straight line but zig zag or zig zig as the case may be,

/ \ /

Taking into account that some carbon atoms may be bonded by DOUBLE bonds,

C-C=C-C

which means

    H   H
    |   |
H   C   C-H
 \ / \\/ \
H-C   C   H
 /    |
H     H
So if the left out parts per the above rules were added to half of the lutein molocule as illistrated by a normal stick formula it would look like

lutein with C&H

and it becomes apparent that the shorthand stick representation makes things much neater.

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