Flashcards in Nitrogen Metabolism/Urea Cycle Deck (64)
What are the dietary fuels
1. Carbohydrates - sugars and starches ( store glycogen in skeletal muscle and liver)
2. Lipids (store as triglycerides in adipose tissue)
3. Proteins - amino acids
We dont store amino acids ; we ____them down
No ____ in carbohydrates of lipids
Have to convert nitrogen to ____
where does urea cycle occur
When are aa oxidized for energy?
1. normal protein turnover
2. starvation/diabetes (uncontrolled)
3. protein rich diet (Atkins)
what is nitrogn balance
what you take in vs what you excrete; if intake and excretion are equal it is called N balance; healthy adults
What is + nitrogen balance
Holding all the nitrogen you take in (intake> loss); growing children, pregnancy, illness/trauma recovery
What is - nitrogen balance
loss is greater than your intake; excreting a lot of Nitrogen in urine; you get edema
What is kwashiorkor
The condition of the first born when the second child arrives. the first child who was on breast milk that had all the essential aa's is put on grain diet thats missing essential aa: muscle waisting metabolism!
what maintains fluid in bloodstream vs going into tissues
colloid osmotic pressure; proteins of blood maintain colloid osmotic pressure that draws water in but if your lose protein from your blood bc your using it for energy production the main protein you lose is albumin which prov bulk of colloidic osmotic pressureAs osmotic pressure dec fluid leaves blood and goes into tissues. You get edema.
What is ureotelic
excrete urea- terrestrial animals. 86%
what is ammonotelic
excrete ammonia directly - bony fishes. 2.8%
what is uricotelic
excrete uric acid- birds and reptiles. You dont want a bird with a big bladder; birds conserve water in this way. 1.5%
what does the other 4% nitrogen come from
Creatine. Which comes from muscle
What is peristalsis and stomach acid important for
open up proteins and dentature them; make them more accesible to proteases and cleave them into ind aa that can be asorpeed by brush border in intestine.
What do mucosal cells produce
Gastrin; hormone that binds to receptors on T cells that cause them to secrete pepsinogen (inactive precursor protein) and it also makes histamine which makes HCl via parietal cells.
What is the end result of the digestive system
How does pepsinogen turn to pepsin
Pepsinogen-->pepsin-->active and auto cleaves itself which starts process of protein digestion slightly
Secretion initiated by CNS input is via
What does atropine, probanthine do
blocks acetylcholine interaction with muscarinic receptors.
What does cimetidine or ranitidine block
histamine interaction with H2 receptors
What are the two hormones that the intestinal mucosa produces
cholecyskokinin: causes gall bladder to secrete bile salts to emulsify fats.
secretin: targets exocrine pancreas; secretes things into intestine which secretes zymogens and bicarbonate.
What is the enzyme that the intestinal mucosa produces:
enteropeptidase which activates trypsinogen-->trypsin--> pancreatic zymogens: pro carboxypeptidase
What are the enzymes involved in gall bladder and bile salts
chymotrypsinogen, procarboxypeptidase and proelastase
what do secretory cells secrete and what is the end result of it
zymogens and bicarbonate. End result is a single amino acids!
What are the different classes of aa that the intestine uses for active transport systems
2. basic and Cys
3. imino and Gly
5. beta amino acids: beta alanine, taurine
What is Hartnup's disease
similar to pellagra; niacine deficiency; bc this transporter transports tryptophan. you get dermatitis, diarrhea and dementia and inflammation of tongue and oral cavities.
how do you get amino acids
from intracellular protein or dietary proteins