MCP non-structure questions Flashcards
breakdown of glycogen to glucose
glycogenolysis
glucose polymer humans cannot digest
cellulose
organ responsible for maintaining blood glucose levels
liver
sugar polymer containing 2-15 sugars
olgiosacch
disaccharidase that cleaves glucose dimers with alpha 1-4 linkage
maltase
type of enzyme that cleaves sugar polymers at internal linkages
endoglycosidase
non glucose component of lactose
galactose
oxidation of glucose to produce ATP
glycolysis
first enzyme to act in carb digestion
amylase
table sugar= glucose + ____
fructose
branched polysacch in starch
amylopectin
humans store glucose as the polymer ___
glycogen
disaccharidase that cleaves table sugar
sucrase
type of enzyme that cleaves sugar-sugar linkages
glycosidase
brush border enzyme that cleaves alpha dextrins to glucose and isomaltose
glucoamylase
source of digestive enzymes in mouth
salivary gland
glucose disacch with alpha 1,6 glycosidic bond
isomaltose
branched oligosacch products of amylopectin digestion
dextrins
hormone signaling that blood glucose is low
glucagon
hormone signaling that blood glucose is high
insulin
organ that synthesizes digestive enzymes for the small intestine
pancreas
(hexokinase/glucokinase) has a very high affinity for glucose
hexokinase
what is the purpose behind glucokinase’s low affinity for glucose
it only converts when glucose levels are very high
when the cell needs energy, ___ enters glycolysis
G6P
which enzyme plays a central role in regulation of glycolysis
PFK
the rxn catalyzed by PGK is an example of what type of reaction
substrate level phosphorylation (also the PK reaction)
net gain of glycolysis
2 ATP
2 NADH
2 pyruvate
fructose in the muscle is converted to F6P by (hexokinase/glucokinase)
hexokinase
fructose in the liver is converted to GAP by (hexokinase/glucokinase)
glucokinase
deficiencies in F1P aldolase cause (2 things)
liver damage and hypoglycemia
a deficiency in galactokinase results in galactitol formation which causes
cataracts
a deficiency in UMP transferase causes (two things)
mental retardation, liver failure
simple treatment for UMP transferase deficiency
screen newborns, then eliminate lactose
cost of temporarily storing glu units in glycogen in the muscle: G6P > glycogen > G6P
1 ATP to prime G1P for glycogen synthase
.1 ATP to convert 10% of units released from 1-6 linkages as glu to G6P
total: 1.1 ATP per G6P
cost of temporarily storing glu units in glycogen in the liver: Glu > glycogen > Glu
1 ATP to convert glu to G6P
1 ATP to prime G1P for glycogen synthase
total: 2 ATP per glu
(Von Gierke/Anderson) dz: defective glucose-6-phosphatase or transport system, affects liver and kidney
Von Gierke
(Von Gierke/Anderson) dz: defective branching enzyme (alpha 1,4 > alpha 1,6), affects liver and spleen
Anderson
in Von Gierke dz, glycogen is (increased/decreased), with a normal structure
increased
clinical features of Von Gierke dz
massive enlargement of liver, failure to thrive, severe hypoglycemia, ketosis, hyperuricemia, hyperlipemia
clinical features of Anderson dz
progressive cirrhosis of liver, liver failure causes death, usually before age 2
McArdle dz has a defective ____ enzyme and affects muscles
phosphorylase
clinical features of McArdle dz
limited ability to perform strenuous exercise because of painful muscle cramps
glycogen is (increased/decreased) in McArdle dz, with normal structure
moderately increased
why is glycogen synthesis and breakdown tightly regulated
to avoid a futile cycle (cost!)
what type of enzyme catalyzes cleavage of fructose 1,6 bisphosphate into DHAP and GAP
aldolase
(glycogen synthesis/glycolysis): phosphoglucomutase plays a direct role
glycogen synthesis
enzyme that catalyzes conversion of G6P to F6P
isomerase
which enzyme has a phosphotidyl intermediate: (enolase/ lactate dehydrogenase/phosphoglycerate mutase)
phosphoglycerate mutase
amino acid precursor of dopamine
tyrosine
amino acid precursor of epi
tyrosine
amino acid precursor of GABA
glutamate
amino acid precursor of histamine
histidine
amino acid precursor of melanin
tyrosine
amino acid precursor of melatonin
tryptophan
amino acid precursor of norepi
tyrosine
amino acid precursor of serotonin
tryptophan
amino acid precursor of niacin
tryptophan
amino acid precursor of thyroxine
tyrosine
rate limiting step in catecholamine biosynthesis
tyrosine hydroxylation
clinical correlation: Parkinson’s patients are treated with ____ since it will cross the BBB and hopefully increase production of ____
DOPA, dopamine
dopamine formation requires which cofactor: (pyridoxal phosphate/Vitamin C)
pyridoxal phosphate
norepi formation requires which cofactor: (pyridoxal phosphate/Vitamin C)
Vitamin C
catechols are degraded by an enzyme called:
monoamide oxidase (MAO)
clinical correlation: inhibitors of monoamide oxidase (MAO) are used as _______
anti depressants
clinical correlation: defect in biosynthesis of melanins causes:
albinism
clinical correlation: deficiency in tryptophan that leads to a niacin def
Pellagra
four D’s of Pellegra
dermatitis, dementia, diarrhea, death
the body needs ____ for: formation of methionine from homocysteine, biosynthesis of purines and pyrimidines, biosynthesis of glycine
one carbon groups
biotin is a carrier of ___
CO2, the most oxidized one carbon group
THF is a carrier of ___
one carbon groups
sulfa drugs inhibit the synthesis of ____ by bacteria
folate
what is the purpose of the poly-gamma-glutamyl side chain on folic acid?
keeps folic acid trapped inside cells
formation of N5-methyl form of THF is (reversible/irreversible) in humans
irreversible
clinical correlation: patients who are deficient in the enzyme that makes the N5 form of THF have a higher risk of ___ and a lower risk of ____
higher risk of atherosclerosis/heart disease
lower risk of colon cancer
folate deficiency affects what type of tissues, and what is the first symptom
rapidly dividing tissues/cells, first symptom is anemia
three drugs that give you folate def
oral contraceptives, barbiturates, methotrexate (chemo)
clinical correlation: birth defect from folate def
spina bifida
clinical correlation: elevated levels of homocysteine are strongly correlated with increased risk of:
atherosclerosis
clinical correlation: def of cystathionine synthase, children die by age three or four of heart disease or stroke
homocystinuria
clinical correlation: def of cystathionase
cystathioninuria
clinical correlation: def of THF and B12 leads to:
megablastic anemia, immature RBCs are released into circulation, pernicious
__ def is associated with demyelination and degeneration of the spinal cord, usually seen when there is a problem with intrinsic factor
B12 (intrinsic factor carries B12 from gut into blood stream)
clinical correlation: B12 def causes folate def, but then folate is supplemented. Result is neurological problems but no anemia
Folate trap
enzyme that cleaves FBP into DHAP and GAP
aldolase
phosphoglucomutase plays a direct role in (glycolysis/glycogen synthesis)
glycogen synthesis
enzyme that converts G6P to F6P
isomerase
enzyme with a phosphohistidyl intermediate (enolase/glycogen synthase/phosphoglycerate mutase)
phosphoglycerate mutase
three organs where mitochondria are most plentiful
heart, kidney, liver
clinical correlation: Vit B1 def (pyruvate builds up), TPP is needed for reaction
Beri Beri
clinical correlation: dihydrolipoamide is the site of action of ____ poisoning
arsenite
the succinyl CoA > succinate reaction illustrates the ____ principle
common intermediate principle (product of first reaction is substrate for second reaction, couples an exergonic rxn to an endergonic rxn)
why is it good that the oxidation of malate by NAD+ is difficult so very little OAA is in in eqbm with a lot of malate?
so malate can exit to cytoplasm during resting state and serve as a substrate for gluconeogenesis
a membrane transport system is present in the IMM to transport (NADH/CO2/pyruvate)
pyruvate
the reaction catalyzed by aconitase in TCA cycle is: (condensation-hydrolysis/dehydration-rehydration)
dehydration-rehydration
which enzyme illustrates common intermediate principle (hexokinase/adenylate kinase/succinyl CoA synthetase)
succinyl CoA synthetase
during respiration, you need lots of (NAD/NADP)
NAD
for detox and biosynthesis, you need lots of (NAD/NADP)
NADP
clinical correlation: two consequences of G6PDH def
favism (hemolytic anemia), advantage where malaria is endemic (most common enzyme def)
pyruvate carboxylase is found where specifically
only in mitochondria
the only aa’s that cannot contribute to gluconeogenesis (two)
Leu and Lys
acetyl CoA from ____ and ___ cannot contribute to gluconeogenesis
fatty acids and aa’s
biotin is bound to which enzyme (PEPCK/G6phosphatase/pyruvate carboxylase)
pyruvate carboxylase
which enzyme does not function in reversible nonoxidative phase of pentose phosphate shunt (epimerase/isomerase/lactonase/transaldolase/transketolase)
lactonase
which kinase in glycolysis functions reversibly in gluconeogenesis
phosphoglycerate kinase
if O2 is not available for mitochondrial respiration, the ETC will:
stop
if O2 supply is blocked then suddenly restored, cyt c would begin shifting toward its oxidized state (before/after) the pool of coenzyme Q would shift toward its oxidized state
before
(cyt c/NAD+/ubiquinone/FeS): acts as a mobile H+/e- carrier in a Mitchell Loop type of direct coupling mechanism between e- transfer and H+ transport across a membrane layer
ubiquinone
(ubiquinone/cyt c) is the e- donating substrate for cytochrome oxidase
cyt c
(cyt c/FeS/FMN/CuB) can accept 2 e- per turnover
FMN
the three catalytic subunits of F1 are (independent/cooperative)
cooperative
(ADP/Pi/O2/CO2) enters the mit matrix through an electroneutral transporter driven by the change in pH component of the electrochem gradient
Pi (O2 and CO2 diffuse, ADP is exchanged with ATP by electrical potential, not H potential)
(pyruvate DHase/pyruvate kinase/phosphorylase kinase/glycogen synthase) is inactivated when blood sugar increases and insulin is released
phosphorylase kinase
F26BP activates (FBPase/PFK)
PFK
following phosphorylation by protein kinase A, phosphorylase kinase activates (glycogen branching enzyme/glycogen phosphorylase/glycogen synthase/phosphoprotein phosphatase)
glycogen phosphorylase
three benefits to storing energy as fat
1-lower oxidation state than carbons in carbs or protein
2-stored without bound water
3-don’t participate in cell’s osmotic balance so cells can store enormous amounts
myristic fatty acid has _ carbons and _ dbs
14 carbons, no dbs
palmitic fatty acid has _ carbons and _ dbs
16, no dbs
palmitoleic fatty acid has _ carbons and _ dbs
16, 1 db
stearic fatty acid has _ carbons and _ dbs
18, 0
oleic fatty acid has _ carbons and _ dbs
18, 1
linoleic fatty acid has _ carbons and _ dbs
18, 2
linolenic fatty acid has _ carbons and _ dbs
18, 3
arachidonic fatty acid has _ carbons and _ dbs
20, 4
clinical correlation: failure of bile production or blockage of bile flow, exocrine pancreas dysfunction or obstruction of pancreatic duct, failure of uptake into intestinal mucosal cells cause:
fatty stool
fatty acids are released from lipoproteins by the action of ______ (enzyme) located in the capillary endothelial walls of muscle and adipose tissue
lipoprotein lipase
hepatic lipase processes ___
LDL
oxidation of triacylglycerols to CO2 and H2O yields 9kcal/g while carbohydrate yields __kcal/g
4
pancreatic lipase catalyzes the partial hydrolysis of ____
triglycerides
entry of nonesterified long chain fatty acids from the intestinal lumen into the intestinal mucosa is mediated by:
protein carriers
major constituents of ____ are cholesterol, bile salts, and phosphatidylcholine
bile
excess lipid in feces is called
steatorrhea
a def in lipoprotein lipase would most likely cause abnormalities in (digestion of fat in intestine/unloading of free fatty acids from VLDL/synthesis of VLDL/synthesis of chylomicrons)
unloading of free fatty acids from VLDL
Apo__ in mature chylomicrons is recognized by lipoprotein lipase
ApoCII
albumin has bound (triglycerides/non esterified fatty acids)
non esterified fatty acids
(triglycerides/non esterified fatty acids) are found in substantial amounts free in solution
neither
lipoproteins contain lots of (triglycerides/non esterified fatty acids)
triglycerides
mixed micelles contain (non esterified fatty acids/triglycerides/both)
non esterified fatty acids
mnemonic for ten essential amino acids
PVT. TIM HALL
ten essential amino acids
Phe, Val, Thr, Trp, Ile, Met, His, Arg, Leu, Lys
cystein becomes essential if ____ (aa) is low
methionine
tyrosine becomes essential if ____ (aa) is low
Phe
clinical correlation: patients defective in pancreatic enzymes, must supplement with pancreatic enzymes
CF
clinical correlation: a defect in the transport system for neutral and aromatic aa’s including Trp from the gut and renal tubules. Niacin def, diarrhea, dermatitis, dementia, death, find neutral and aromatic aa’s in urine and feces
Hartnup’s disease
clinical correlation: def in transport system for basic aa’s and cystine from gut and renal tubules, UTI’s and kidney stones, treat with fluids and penicillamine
cystinuria
urinary levels of which compound can provide a measure of muscle protein breakdown
3-methyl histidine
(children and convalescing adults/diseases of wasting and starvation) show positive nitrogen balance
children (growing) and convalescing adults (rebuilding)
(children and convalescing adults/diseases of wasting and starvation) show negative nitrogen balance
diseases of wasting and starvation
names with “glut” usually have _ carbons (#)
5
amino acid degradation is located in the (mitochondria/cytoplasm) for urea cycle
mit
amino acid degradation is located in the (mitochondria/cytoplasm) for pyrimidine nucleotide biosynthesis
cytoplasm
pyridoxal phosphate is vitamin B_
B6
essential cofactor for all transaminations
pyridoxal phosphate B6
__ (aa) can be easily made from pyruvate, efficient way to send 3 carbon groups back to liver to be easily converted into glucose while disposing of an NH4+ grp, one of most abundant aa’s in blood
Ala
__ (aa) is one of most abundant aa’s inside cells, transaminases converge on it, and through oxidative deamination you can make energy from ripping off the NH4+
glutamate
glutamate is mainly deaminated in the (muscles/liver/blood)
liver
most common defect in urea cycle
OTC defect (X linked gene)
four benefits of using urea to dispose
1-carries two ammonia groups
2-soluble
3-non protonable–keeps solution pH 7.2
4-low reactivity
how is the urea cycle regulated
nitrogen balance
protein free diet: levels of urea cycle enzymes (increase several fold/decrease)
decrease
high protein diet: levels of urea cycle enzymes (increase several fold/decrease)
increase several fold
clinical correlation: sign of OTC defect
ammonia intoxication
if citrulline builds up in the urea cycle, what happens to the individual
mental retardation
arginine is an essential amino acid for what process in children
growth
in the urea cycle, (alpha keto glutarate/aspartate/carbomyl phosphate) is generated from CO2 and NH4+
carbomyl phosphate
clinical correlation: Pellagra’s disease can be the result of ____ disease
Hartnup’s disease (def of niacin)
the two most abundant aa’s inside our cells
glutamate and glutamine
transamination of alanine by alanine transaminase generates (fumarate/acetyl CoA/pyruvate)
pyruvate
which aa? easily converted to Pro, synthesized from ornithine in urea cycle, glucogenic aa that can be converted to alpha ketoglutarate
arginine–also, essential for growth
glutamate is the precursor for which NT
GABA
clinical correlation: irritability, vomiting, lethargy, confusion, resp distress, migraines are all symptoms of _____ toxicity
ammonia toxicity
(ketogenic/glucogenic): aa’s are degraded to either acetyl CoA or acetoacetyl CoA
ketogenic–give rise to ketone bodies
(ketogenic/glucogenic): aa’s are degraded to pyruvate or TCA cycle intermediates
glucogenic–give rise to glucose via formation of phosphoenolpyruvate
brain’s preferred energy source
glucose
acetyl CoA can be converted to (fatty acids/glucose/both)
fatty acids
cofactor in conversion of glycine to serine
THF
enzyme used to degrade branched chain amino acids
BCAT: branched chain aa transaminase
clinical correlation: ____ (enzyme) def in mice shows increased insulin sensitivity, increased protein turnover, increased serum Leu levels, decreased fat and body weight, increased energy expenditure
BCAT–Leucine builds up
clinical correlation: defect in branched chain keto acid DHase, build up of keto acids give urine a characteristic odor, tx by restricting keto amino acids (Val, Leu, Ile) or administering high doses of thiamine
maple syrup urine disease/branched chain ketoaciduria
clinical correlation: a genetic disorder assoc with inability to catalyze hydroxylation of Phe and build up of toxic derivatives of Phe (phenylpyruvate), mental retardation in infants if not detected early
PKU–phenylketonuria
tx for PKU
restrict Phe in diet until at least 16 years old
maternal PKU
mother has PKU and isn’t being treated, in utero levels are high
clinical correlation: defect in homogentisate oxidase, deposits in cartilage causes arthritis at a young age, diagnose by looking through earlobe at darkened cartilage
alkaptonuria
clinical correlation: high levels of homocysteine, high risk of atherosclerosis, oxidizes LDL
homocystinuria
treatment for homocystinuria
PLP cofactor
(proline/arginine) is synthesized and degraded through the same pathway
proline
serine (is glucogenic/can be made from aspartate)
is glucogenic
maple syrup urine disease caused by defect in (alpha keto acid DHase/phenylalanine hydroxylase)
alpha keto acid DHase
PKU caused by defect in (alpha keto acid DHase/phenylalanine hydroxylase)
Phe hydroxylase
Ala, Ser, Cys, Gly, Thr can all be degraded into:
pyruvate
vitamin B12 is found in the (hydroxy/adenosyl) form in methylmalonic acid mutase
adenosyl
when THF builds up as N5 methyl THF
folate trap
what donates the methyl group in conversion of NE to epi
SAM (S adenosylmethionine)
three amino acids that require B12 for the degradation of their carbon skeletons
Val, Ile, Met
spinal cord degeneration and other neuro problems during B12 def (can be cured by administration of folic acid/are caused by a deficiency in the conversion of methylmalonyl CoA to succinyl CoA)
are caused by a deficiency in the conversion of methylmalonyl CoA to succinyl CoA
most reduced form of THF (N5 methyl/N5 formyl)
N5 methyl
not made from tyrosine (dopamine/melanin/serotonin/NE)
serotonin
HMG-CoA reductase is (more active in fed state than fasted state/less active in fed state than fasted state)
more active in fed state
glycogen phosphorylase is (more active in fed state than fasted state/less active in fed state than fasted state)
less active in fed state
pyruvate kinase is (more active in fed state than fasted state/less active in fed state than fasted state)
more active in fed state
acetyl CoA carboxylase is (more active in fed state than fasted state/less active in fed state than fasted state)
more active in fed state
liver PFK-2 is (more active in fed state than fasted state/less active in fed state than fasted state)
more active in fed state
hormone sensitive lipase is is (more active in fed state than fasted state/less active in fed state than fasted state)
less active in fed state
in going from an overnight fast to prolonged starvation, glycolysis in the brain (increases/decreases)
decreases
in the basal state, which contributes over half the kcal used (glucose/fatty acids)
fatty acids
coritsol promotes but epi inhibits (gluconeo in liver/glycogen synthesis in liver)
glycogen synthesis
when epi is released due to excitement, (dephosphorylation of perilipin in adipocytes/liver degrades glycogen and makes glucose)
liver degrades glycogen and makes glucose via gluconeogenesis
(high/low) energy and glucose levels are associated with decreased activity of cAMP dependent protein kinase
low
enzymes required during (fed/fasting) states are activated by phosphorylation
fasting
basal state: (feeding/fasting)
fasting
synthesis of triacylglycerols in adipocytes: (fasting/feeding)
feeding
elevated insulin/glucagon ratio: (fasting/feeding)
feeding
highest rate of fatty acid uptake by liver cells: (fasting/diabetes type I)
diabetes type I
lowest rate of muscle proteolysis: (feeding/starvation)
feeding
maximal production of acetoacetate by liver (starvation/diabetes type I)
diabetes type I
intermediate of major significance in nucleotide metabolsim
PRPP (an activated ribose ready for base attachment)
(azaserine/sulfonamide) blocks amide transfer from glutamine
azaserine (an analog of glutamine), inhibits IMP synthesis
(azaserine/sulfonamide) blocks biosynthesis of folic acid in bacteria and prevents its formation, blocking nucleotide synthesis
sulfonamide
IMP converted to (AMP/GMP) requires seven phosphoanhydride bonds
AMP
IMP converted to (AMP/GMP) requires eight phosphoanhydride bonds
GMP
what is the rate determining step of IMP synthesis
first two steps, feedback inhibition
clinical correlation: patients with ____ (enzyme) def build up high levels of pyrimidines in their serum and urine, first step is rate limiting step and excess carbamoyl phosphate that builds up is converted to pyrimidines
OTC def (urea cycle)
ribonucleotide reductase is present in (all cells all the time/replicating cells during replication)
replicating cells during replication
clinical correlation: ribonucleotide reductase is inhibited by ____, a potent chemotherapy agent
hydroxyurea
(F-UMP/methotrexate) looks like a uracil but a fluorine at the 5 position causes permanent (suicide) inhibition
F-UMP/5-Fluorouracil
(F-UMP/methotrexate) is an analog of folic acid that blocks regeneration of THF
methotrexate
molybdenum is required in trace amounts in humans because ______ (enzyme in purine degradation) uses it
xanthine oxidase
clinical correlation: def of adenosine deaminase in purine degradation leads to what condition that can be treated with gene therapy
SCID–severe combined immunodef
xanthine oxidase generates _____
superoxide
clinical correlation: the enzymes required to degrade pyrimidines also are used to clear which chemo agent
5-Fluorouracil–if you are def in this enzyme (no clinical signs) and get cancer and use 5-F as your chemo, you will die from the treatment
clinical correlation: due to overactive PRPP or partially deficient HGPRT (X linked)
gout
clinical correlation: caused by precipitation of sodium urate crystals in joints and kidneys
gout
clinical correlation: treat ___ with allopurinol which blocks the production of uric acid
gout
allopurinol inhibits which enzyme used in the production of uric acid
xanthine oxidase
clinical correlation: ____ (drug) is often given as a pretreatment for chemo to prevent uricemia
allopurinol
clinical correlation: complete lack of HGPRT activity, X linked recessive, severe
Lesch-Nyhan syndrome
clinical correlation: symptoms include hyperuricemia, gout, urinary tract stones, MR, spasticity, self mutilation
Lesch-Nyhan syndrome
clinical correlation: treatment of _____ with allopurinol reduces the uric acid formation but does not alleviate the neurological symptoms
Lesch-Nyhan syndrome
clinical correlation: adenosine deaminase def
severe combined immuno def SCID
clinical correlation: treat this by bone marrow transplant and enzyme replacement, gene therapy is experimental
SCID
clinical correlation: genetic disorder of pyrimidine synthesis, ___ acid accumulates in blood and is excreted in urine, alleviated by feeding of uridine or cytidine
orotic aciduria
(methotrexate/5-Fluorouracil) leads to the inhibition of thymidylate synthase
5-Fluorouracil
(sulfonamide/azaserine) blocks the synthesis of GMP from IMP, blocks synthesis of CTP from UTP
azaserine
HGPRT is used to salvage (pyrimidine/purine) nucleotides
purine
allopurinol is often given to patients in conjunction with chemo because (it inhibits salvage of purines/the destruction of cancer cells releases large amounts of purines)
the destruction of cancer cells releases large amounts of purines
the (purine/pyrimidine) ring is formed directly on the ribose phosphate
purine
because glutamine is used in multiple steps during purine synthesis, this pathway is inhibited by (azaserine/sulfonamides)
azaserine
GTP is made using (N5 methyl THF/phosphoribosyl pyrophosphate)
phosphoribosyl pyrophosphate
pyrimidines are made from (carbamoyl phosphate and aspartate/ribonucleotide reductase and thymidylate synthase)
carbamoyl phosphate and aspartate
sulfonamides (inhibit PRPP synthase/are analogs of p-amino benzoic acid)
are analogs of p-amino benzoic acid
5-Fluorouracil leads to inhibition of (dihydrofolate reductase/thymidylate synthase)
thymidylate synthase
de novo synthesis of AMP requires (GTP and ATP/5-methyl THF)
GTP and ATP
thymidylate synthase (requires dihydrofolate reductase for maximal activity/converts dUTP to dTTP)
requires dihydrofolate reductase for maximal activity
(glucagon/insulin) signals the cell to take up fat and store it
insulin
role of perilipins
form a shield around TG to block enzymatic action
how are perilipins removed
when the they are phosphorylated by cAMP dependent PKA, they are removed
how is hormone sensitive lipase activated
by phosphorylation by cAMP dependent PKA (same as perilipin–convenient!)
what does insulin do to hormone sensitive lipase
it deactivates it by dephosphorylating it by upregulating a phosphatase
cAMP is activated by (insulin/glucagon/epi/NE)
glucagon, epi, NE
when free fatty acids are released inside the adipocyte, how do they get to the blood
attach to adipocyte lipid binding protein, travel through blood attached to albumin
what type of receptor is the glucagon receptor on the fat cell
GPCR (goes to adenlyl cyclase, to cAMP, to PKA, to enzymes)
(delta/omega) nomenclature: start counting at end (not the acid end)
omega
(delta/omega) nomenclature: start counting at beginning (the acid end)
delta
the second db in omega nomenclature is usually _ carbons later
3
(palmitoleic and oleic/linoleic and linolenic) fatty acids are essential (we can’t make them de novo)
linoleic and linolenic
CPT1 in carnitine shuttle is inhibited by
malonyl CoA (intermediate in FA synthesis)
enzyme in fatty acid activation in first part of beta ox
acyl-CoA synthetase/thiokinase
three steps in the beta ox of fatty acids are catalyzed by:
one multifunctional protein with all three enzymes
clinical correlation: def in medium chain acyl CoA dehydrogenase, see symptoms in (hyper/hypo) glycemia
hypoglycemia (because that’s when you need to really start breaking down fatty acids)
symptoms of medium chain acyl CoA DHase def:
liver dysfunction, seizures, coma
(6/8) ATP oxidized per carbon in glycolysis
6
(6/8) ATP oxidized per carbon in beta ox
8
where are KB’s made specifically (organ and organelle) and where are they used?
made in liver mitochondria
used NOT in liver
KB’s are made during starving or when there’s no glucose in diet because the TCA cycle is (active/stalled)
stalled–so what to do with the acetyl CoA’s building up? Make KB’s!
KB (over/under) production occurs in Type I diabetes
over production
clinical correlation: when KB’s build up in blood
ketoacidosis, blood gets acidic, coma (Type I diabetes)
why does ketoacidosis not occur in Type II diabetes
there is some insulin still
ATP yield from complete beta ox of palmitic acid
129 ATP
ATP yield from complete beta ox of palmitoleic acid (16:1 delta 9)
127 ATP
where would you find adipocyte lipid binding protein
in adipose tissue and many other tissues
where would you find HMG-CoA lyase
liver tissue (NOT adipose)
where would you find glycerol kinase
liver and sometimes adipose tissue
carbons in TGs have a (higher/lower) oxidation state than carbons in carbs or proteins, so the are worth more energy
lower
TG’s are stored (bound to water/unbound)
unbound
TG’s (do/don’t) participate in the cell’s osmotic balance
do not–so you can store lots
after a fatty meal, what happens to your serum
milky serum
medium chain fatty acids are found in what body secretion
breast milk
NEFA
non esterified fatty acids aka free fatty acids
brain (can/cannot) use free fatty acids as fuel
cannot–BBB prevents transport
four fat soluble vitamins
DAKE
role of bile in fat digestion
emulsifies the fat droplet so enzymes can access the bonds
activation of pancreatic lipase requires formation of a complex with:
colipase and a droplet of emulsified lipid
a pancreatic lipase cleaves the TG into
two free fatty acids and one monoacyl glycerol (the middle one stays on)
stool in CF
fatty because pancreatic lipase can’t get out of the pancreas to digest fats
important Apoprotein for chylomicron formation
B48
tag on chylomicron for lipoprotein lipase
CII
enzyme that clears chylomicrons from the capillaries
lipoprotein lipase
products of lipoprotein lipase
3 non esterified fatty acids and 1 glycerol
(lipoprotein lipase/pancreatic lipase) digests the TG into two free fatty acids and one MAG
pancreatic lipase
chylomicrons are (slowly/rapidly) cleared from the serum
rapidly
VLDLs have a (shorter/longer) circulating half life than chylomicrons. They are also broken down by lipoprotein lipase
longer
clinical correlation: severe calorie def, no subcutaneous fat, gross loss of muscle, easily wrinkled skin, thin dry hair, apathy/anxiety
marasmus
treatment for marasmus
avoid refeeding syndrome–give small meals at frequent intervals
clinical correlation: edematous malnutrition, severely def in protein
Kwashiorkor
(marasmus/Kwashiorkor): pale skin with burn like lesions, cyanotic extremities, brittle hair, hepatomegaly, irritability, edema, hypoglycemia
Kwashiorkor
conversion of acetyl CoA to ketone bodies yields slightly (more/less) energy than oxidation in TCA cycle
slightly less energy
BMI less than 18.5 is classified by WHO as
underweight
BMI 18.5-24.9 is classified by popular description as
healthy, normal
BMI 25-29.9 is classified by WHO as
grade 1 overweight (overweight)
BMI 30-39.9 is classified by WHO as
grade 2 overweight (obese)
BMI 40+ is classified by WHO as
grade 3 overweight (morbidly obese)
