Glycine is a building block used to make proteins, such as those in heart muscle. How many valence electrons are in glycine?

Glycine (C2H5NO2) contains a total of 20 valence electrons.

Here's the breakdown:
Carbon (C) has 4 valence electrons.
Hydrogen (H) has 1 valence electron - there are 5 hydrogen atoms in glycine, so 5 x 1 = 5 valence electrons.
Nitrogen (N) has 5 valence electrons.
Oxygen (O) has 6 valence electrons - there are 2 oxygen atoms in glycine, so 2 x 6 = 12 valence electrons.

Adding these up: 4 (carbon) + 5 (hydrogen) + 5 (nitrogen) + 12 (oxygen) = 26 valence electrons.

However, glycine is an amino acid, and one of its hydrogen atoms is involved in bonding with another molecule, leaving a net charge of -1 on the glycine molecule. Therefore, we subtract one hydrogen atom, thereby removing one valence electron.

Final calculation: 26 (total valence electrons) - 1 (hydrogen atom) = 25 valence electrons in glycine.