amino acid metabolism I - Breakdown Flashcards
protein sources:
- stomach- ____ pH denatures proteins and activates ____
- small intestine
- ____ in the duodenum cleaves trypsinogen
- ____ are exopeptidases (chew from N-term)
- ____ break apart dipeptides
- ____ ____ , ____ , and ____ can be transported into cells
- low, pepsin
- enteropeptidase
- aminopeptidases
- dipeptidases
- enteropeptidase
- amino acids, dipeptides, and tripeptides
protein sources: intracellular:
- the ____
- the ____
- N-end rule: N-terminal amino acid identity dermines:
- polar/charged amino acids have the ____ half-life
- N-end rule: N-terminal amino acid identity dermines:
- lysosome
- proteasome
- rate of ubiquitination
- shortest
- rate of ubiquitination
what can we do with individual amino acids:
REDUCE - remove nitrogen through the urea cycle
REUSE - make new proteins
RECYCLE - repurpose the carbon skeleton
____ ____ is always the coenzyme for deaminatio
pyridoxal phosphate
direction deamination by serine dehydratase:
- remove H2O = ____
- add H2O back to remove NH4+ = ____
- serine is deaminated to form ____
- dehyration
- deamination
- pryuvate
most amino acids follow a 2 enzyme mechanism of deamination:
- step 1: aminotransferases make ____
- using ____
- step 2: ____ ____ releases an ____ ion
- and rengerates ____
- glutamate
- alpha-ketoglutarate
- glutamate dehydrogenase, ammonium
- alpha-ketoglutarate
Aspartate Aminotransferase (AST) - in ____
Serum Glutamate-Oxaloacetate Transaminase (SGOT) - in ____
catalyzes the interconversion of ____ and ____
cells
serum
aspartate and oxaloacetate
Alanine Aminotransferase (ALT) - in ____
Serum Glutamate-Pyruvate Transaminase (SGPT) - in ____
catalyzes the interconversion of ____ and ____
cells
serum
alanine and pyruvate
urea cycle:
- NH4+ is a toxic byproduct of amino acid ____
- NH4+ can be converted to urea in the ____
- urea is transported to the ____ to be excreted from the body
- muscle cells transport their NH4+ to the liver via ____ and the action of ____
- all other cells transport their NH4+ to the liver via ____
- ____ ____ adds an amine to Glu to make Gln
- ____ in the liver removes an amine from Gln to make Glu
- catabolism
- liver
- kidneys
- alanine, ALT
- glutamine
- glutamine synthetase
- glutaminase
urea is composed of 4 pieces
NH2 from glutamate
carbonyl from water
central carbon from HCO3
NH2 from aspartate
urea cycle step 1:
- ____ ____ ____ ____ (CPSI) combines NH3 and CO2 to make ____ ____ using 2 ATP
- creation of carbamoyl phosphate is the ____ step in urea cycle
- ____ is an allosteric activator of CPSI
- carbamoyl phosphate synthetase I, carbamoyl phosphate
- committed
- NAG
urea cycle step 2:
- ____ + ____ ⇒ citrulline
- ornithine and citrulline are ____ amino acids
- ornithine msut move into the ____ to combine with carbamoyl phosphate
- citrulline is exported to the ____
- ornithine + carbamoyl phosphate
- nonproteinogenic
- mitochondira
- cytoplasm
urea cycle step 3:
- citrulline + ____ → ____
- ____ donates NH3
- rest of aspartate is ____
- ____ is created
- aspartate → argininosuccinate
- asparate
- fumarate
- arginine
urea cycle step 4:
- arginine → ____
- releases ____
- addition of water when cleaving arginine adds the final ____ of urea
- ornithine enters into the ____ and continues the cycle
- ornithine
- urea
- oxygen
- mitochondria
urea cycle extra step:
- fumarate → → OAA uses ____ cycle
- OAA → Asparate is performed by ____
- TCA
- AST
