Positive charge of NAD+ molecule

  • #1
tickle_monste
69
1
Why is the positive charge of the NAD+ molecule located on the nitrogen in the nicotinamide group? This nitrogen has 4 bonds attached to it, but nitrogen only has 3 holes in its valence shell, so wouldn't this make a negative charge on this nitrogen?
 

Answers and Replies

  • #2
chemisttree
Science Advisor
Homework Helper
Gold Member
3,692
692
Why is the positive charge of the NAD+ molecule located on the nitrogen in the nicotinamide group? This nitrogen has 4 bonds attached to it, but nitrogen only has 3 holes in its valence shell, so wouldn't this make a negative charge on this nitrogen?

Draw the lewis dot structure for the nitrogen in this system and you will see a free lone pair of electrons before protonation by H+. Is it true that when you protonate a neutral molecule with H+ you are left with an anion?
 
  • #3
Ygggdrasil
Science Advisor
Insights Author
Gold Member
2021 Award
3,522
4,179
In general, for determining the formal charge on an atom, we consider all of the electrons in lone pairs and inner shells as belonging to that atom as well ashalf of the electrons in chemical bonds as belonging to that atom. Therefore, the nitrogen has 4 bonds attached to it (giving 4 electrons) plus two inner shell electrons, giving a total of 6 electrons to nitrogen's 7 protons.
 

Suggested for: Positive charge of NAD+ molecule

Replies
3
Views
377
Replies
2
Views
806
  • Last Post
Replies
13
Views
2K
Replies
11
Views
1K
Replies
24
Views
487
Replies
3
Views
2K
Replies
2
Views
1K
Top