BMS Amino Acids
What are AAs buildingi blocks of?
Proteins, glucose, and ketones
What is physiological pH?
AA at neutral pH
AA that contain carbon backbones that can't be made by the body or can't make enough of in the body
-Can be synthesized because carbon skeletons can be make adequately from other precursors
-still require a source of NH3
Source of carbon skeletons
intermediates formed from glycolysis, pentose phosphate pathway, TCA cycle
Source of amino groups
-derived from NH3
-NH3 is necessary but can also be TOXIC
How does the body maintain NH3 homeostasis?
liver converts excess NH3 into urea, which is then eliminated by the kidneys
What two AAs does the body use to both make use of available NH3 and get rid of excesss NH3
-NH3 (NH4+ in H20) can be added to alpha-ketoglutarate to make glutamate
-reaction goes both directions, GLU is also used to get rid of NH3 via urea/kidneys
-can give amino group away to create another AA by TRANSAMINATION
asparatate aminotransferase, alanine aminotransferase
-serum levels of these enzymes can be measured and used as markers of cellular damage
-can be synthesized from glutamate
-major AA that circulates in the blood stream
-primary responsible for taking NH3 from peripheral tissues to kidney where it can be excreted
Kidney Excretion of NH4+
-Glutaminase releases NH3 from Gln (glutamine)
-NH3 is exreted into urine as NH4+
What enzyme release NH3 from glutamine?
What enzyme releases NH3 from glutamate?
What is NH3 excreted into the urine as?
Can excess AAs be stored in the body?
What organ degrades AAs?
What components are AAs degraded into?
-amino groups--> urea
-c-skeletons--> acetyl CoA, TCA intermediates
Where is urea synthesized?
What happens if you have excess of NH3?
neurological sx, coma, death, neurological defects (mental retardation)