Final Flashcards
pyruvate dehydrogenase complex E2
dihydrolipoyl transacetylase
pyruvate dehydrogenase complex E3
dihydrolopoyl dehydrogenase
pyruvate dehydrogenase complex is reversible or irreversible process?
irreversible
5 required cofactors for PDD complex
thiamine pyrophosphate (TPP) lipoic acid coenzyme A FAD NAD
to begin the PDD complex, the E2 subunit must have the 2 thiol groups in the ____ form
oxidized
which subunit catalyzes the first 2 rxns in PDD
E1
which is the slowest rxn subunit
E1
pyruvate is converted to acetyl coA by…..
PDH complex
glucose -> __ pyruvate -> __ acetyl coA, __CO2, __ NADH
2 for all blanks
anaplerotic rxn
replenish the TCA cycle with OAA
ubiquonone (cofactor Q) is water soluble or lipid soluble
lipid soluble
-in membrane not ICF
ATP synthase:
beta-ATP ->
beta-empty
ATP synthase:
beta-empty ->
beta-ADP
ATP synthase:
beta-ADP ->
beta-ATP
2 shuttles that transport reducing equivalents to mitochondrial matrix:
- malate-aspartate shuttle (2.5 ATP / NADH)
2. glycerol-3-phosphate shuttle (1.5 ATP / FADH2)
FAs are stored as triacylglycerols in adipose tissue, specifically in…
the dark-colored lipid droplet
FA oxidation occurs in mitochondria and is made active by binding to coA. This process is made irreversible by…..
cleaving PPi into two organic phosphates
takes a couple days after time of starvation for ___________ levels to begin to increase
ketone body
metabolism of ketone bodies occurs in…
mitochondria
substrates for FA biosynthesis
NADPH and acetyl coA
sources of NADPH for FA biosynthesis
PPP and malic enzyme
1st and rate limiting step of FA biosynthesis
acetyl coA -> malonyl coA
catalyzed by acetyl coA carboxylase
-irreversible rxn
1st substrate to be loaded in FA biosynthesis
acetyl coA to KS
2nd substrate to be loaded on in FA biosynthesis
malonyl coA on ACP
palmitate has ____ carbons
16
palmitate is produced after ___ cycles
7
overall synthesis of palmitate requires
14 NADPH and 6 H2O
-use 1 H2O at the end for hydrolysis
FA elongation occurs in
ER
FA elongation does not use…
ACP, instead coenzymes are active in coA form
rate limiting step in chol synthesis
HMG-CoA to Mevalonate
-enzyme is HMG-CoA reductase
storage form of chol
cholesteryl ester
VLDL transports…
TG from liver
chylomicrons transport…
TG from intestine
LDL and HDL transport….
cholesterol
glycerolipid synthesis starts from..
glycerol-3-phosphate
when does digestion of a protein begin?
when it hits the stomach and then further proceeds into the sm int
2 major products of AA degradation
ammonia and alpha-keto acid
after AA degradation, alpha-keto acid can…
feed into the TCA cycle and some are used for gluconeogenesis
all amino groups get funnelled into…
glutamate
AA & keto acid pairing:
glutamate ->
alpha ketoglutarate
AA & keto acid pairing:
pyruvate ->
alanine
AA & keto acid pairing:
aspartate ->
oxaloacetate
glutamate undergoes oxidative deamination by glutamate dehydrogenase, which has a conenzyme of….
NADP or NAD
-reversible rxn
ammonia formed in peripheral tissues is transported to the liver as…
glutamine and alanine
ammonia is converted to urea in the…
liver
the urea cycle containes rxn in which areas…
mitochondira (first 2) and cytosol (last 3)
rate limiting step of the urea cycle
catalyzed by carbomoyl phosphate synthatase
3 precursors of urea
free ammonia
bicarbonate/CO2
aspartate
represents 2/3 of urea molecule
carbomoyl phosphate synthesis
-bicarbonate and ammonia condense
CPS I is regulated by
allosteric regulation by N-acetylglutamate
-stimulated by arginine
arginase enzyme
uses water to cleave urea off the end of arginine molecule
-last enzyme before generating urea
the 2 connectors between TCA cycle and urea cycle
fumerate and aspartate
congenital hyperammonemia:
defects in the genes coding for all 2 urea cycle enzymes
-arginase defects are less severe
acetyl coA or anything broken down to it, cannot result in NET synthesis of
glucose
3 branched chain AAs
valine
leucine
isoleucine
catecholamines:
dopamine, epinephrine, norepinephrine
-all synthesized from tyrosine
histamines formed from
decarboxylation of histidine
serotonin
tryptophan is precursor, for melatonin as well
creatine is synthesized by using
arginine, glycine, and methionine
ammonia is funnelled into 2 molecules
glutamate and glutamine
glutamine synthetase regulated by
its own products (8)
adenylylation
inhibits enzyme by making it more sensitive to inhibitors
glutamine synthetase adenylylation
each of the 12 subunits undergoes adenylylation individually
-the more adenylylated, the more sensitive to inhibition
SAM
1-carbon transfer
-only methyl groups to N or O atom
TH4 (tetrahydrofolate)
1-carbon transfer
-can donate 5-6 diff 1 carbon units, including methyl
4 diiff rxns to generate active TH4, all catalyzed by
DHFR
all AAs are synthesized from specific intermediates of the
glycolytic, PPP, and TCA cycle pathways
plants can make all 20 AAs using _______ as their only carbon source
glucose
de novo pathway:
ribose comes from
PPP
tx of gout
allopurinol
interconversion of nuclesoside mono, di, and triphosphates:
di -> tri cannot use…
ATP as substrate
RNR (ribonucleotide reductase) only works on
diphosphate nucleotides
the ultimate reductant
NADPH
RNR is made from NADPH
regulation of RNR
products are inhibitors
substrates are activators
RNRs main role
maintains a balanced supply of dNTPs for DNA synthesis
2 pancreas secretions that regulate blood glucose levels
glucagon and insulin
main function of fat cells (adipocytes)
store, maintain, and release TAGs
ghrelin
secreted by empty stomach
-eat more
leptin
secreted by adipose tissue
-eat less
pyruvate dehydrogenase complex E1
pyruvate dehydrogenase
