Only 9 of the 22 "standard" amino acids can't be synthesized de novo by the human body.

How exactly would you make an amino acid from glucose or a fatty acid? There is no nitrogen in either of those.

All those amino acids are made from OTHER amino acids.

http://www.tamu.edu/faculty/bmiles/lectures/biosynaa.pdf

With this: http://en.wikipedia.org/wiki/Citric_acid_cycle

The Critic acid cycle is awesome, but it can not perform nuclear synthesis. It has no way to making nitrogen.

As I've said 3 times already, it makes amino acids from other amino acids.

One of the ingredients is NAD, which is made from tryptophan or aspartic acid, both of which are amino acids.

You are simply wrong, and you need to update your information.

Animals can only make amino acids from other amino acids.

Or niacin: http://en.wikipedia.org/wiki/Niacin

NAD is made of nicotinamide AND Adenine. Adenine is in turn made from the amino acids glycine, glutamine, and aspartic acid.

Are you going to acknowledge you were wrong, and actually learn something? Or will you keep arguing?

Us animals are capable of amino acid synthesis for some amino acids.

> Us animals are capable of amino acid synthesis for some amino acids.

Really? You can make an amino acid from ammonia?

No, you can not. You can only make amino acids from other amino acids.

Here, I'll even link if for you: https://en.wikipedia.org/wiki/Amino_acid_synthesis#From_inte...

Follow each of the pathways there, and you will see. Each non-essential amino acid is made from another amino aid.

Where will you move the post after you find out about niacin?

Nothing has changed in what I said since then.

> Where will you move the post after you find out about niacin?

As I replied elsewhere niacin alone is not enough.