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
which amino acids are glycogenic?
glycine, alanine, valine, proline, methionine, serine, cysteine, asparagine, glutamine, arginine, histidine, aspartate, glutamine
which amino acids are ketogenic
leucine
lysine
which amino acids are both glucogenic and ketogenic
phenylalanine
isoleucine
threonine
tryptophan
tyrosine
amino acids are glucogenic if they are degraded into intermediate molecules that can feed through ____ to reform ____
gluconeogenesis
glucose
amino acids are ketogenic if they are degraded into intermediate molecules that can
be used to create ketone bodies
