http://equalsmcsquared.livejournal.com/ ([identity profile] equalsmcsquared.livejournal.com) wrote in [community profile] fandomhigh2005-11-08 08:15 am
Entry tags:

Biology

Good morning. Please don't forget the sign the roll sheet and remind any classmates electing not to attend that I will be giving out detentions for such. It's getting ridiculous.

Today, we will be discussing amino acid metabolism.

All tissues have some capability for synthesis of the non-essential amino acids, amino acid remodeling, and conversion of non-amino acid carbon skeletons into amino acids and other derivatives that contain nitrogen. However, the liver is the major site of nitrogen metabolism in the body. In times of dietary surplus, the potentially toxic nitrogen of amino acids is eliminated via transaminations, deamination, and urea formation; the carbon skeletons are generally conserved as carbohydrate, via gluconeogenesis, or as fatty acid via fatty acid synthesis pathways.

In this respect amino acids fall into three categories: glucogenic, ketogenic, or glucogenic and ketogenic. Glucogenic amino acids are those that give rise to a net production of pyruvate or TCA cycle intermediates, such as a-ketoglutarate or oxaloacetate, all of which are precursors to glucose via gluconeogenesis. All amino acids except lysine and leucine are at least partly glucogenic. Lysine and leucine are the only amino acids that are solely ketogenic, giving rise only to acetylCoA or acetoacetylCoA, neither of which can bring about net glucose production.

A small group of amino acids comprised of isoleucine, phenylalanine, threonine, tryptophan, and tyrosine give rise to both glucose and fatty acid precursors and are thus characterized as being glucogenic and ketogenic. Finally, it should be recognized that amino acids have a third possible fate. During times of starvation the reduced carbon skeleton is used for energy production, with the result that it is oxidized to CO2 and H2O.

For today's lab, I would like you to determine why certain amino acids are essential and others are considered non-essential.

[identity profile] apocalypsesoon.livejournal.com 2005-11-08 05:00 pm (UTC)(link)
"I had this wierd dream. You were in it. It wasn't a good dream, at the end. I don't know if I should talk about it now or wait until class is over. Freaked me out, lemme tell you."

[identity profile] maias-notebook.livejournal.com 2005-11-08 05:04 pm (UTC)(link)
Maia's mouth fell open slightly. "I" she lowers her voice "I was in it?" Maia was shocked and scared. "We can talk about it now or after class." Maia's heart was pounding.


((OOC: if you want make a post for them to talk and I will go to that one or they can continue here. Mun is very intrigued now about this dream))

[identity profile] apocalypsesoon.livejournal.com 2005-11-08 05:15 pm (UTC)(link)
"Well, you were in it as one of the good guys, after... You were one of the good guys. And someone said you could help. And she was in it, too," John said, nodding his head back towards Wednesday.

((OOC: here, for when class is over and John can talk about it more freely (http://www.livejournal.com/community/fandomhigh/332669.html?thread=16044157#t16044157). And the dream itself is in John's journal as of 10 minutes ago.))