11. Kevin Bryan Reviewer Flashcards
organelle responsible for packaging proteins
golgi apparatus
organelle - ATP production
mitochondria
Unfolding of a molecule ≈ effects in entropy
large increase ÎÎ in entropy
decrease the activation energy of rxn
enzymes
the lower the Km of an enzyme ≈ effect on affinity
higher affinity
competitive inhibition can be overcome by
increasing the substrate
site of ETC (electron transport chain)
mitochondria
cyanide inhibits what COMPLEX of ETC?
Complex 4
Blocks electron transport and ATP synthesis by inhibiting the exchange of ATP and ADP across the inner mitochondrial membrane
ATP ADP
atractyloside
catalyzes rxn that yields wate and hydrogen peroxide
superoxide dismutase
- unpaired electron
- persist for short period of time
- ex. superoxide dismutase
free radicals
glucose and galactose are epimers on
carbon 4
glucose and mannose are epimers on
carbon 2
Blocks electron transport and proton pumping at Complex III
azide
carbon monoxide
Blocks electron transport and proton pumping at Complex I.
rotenone
Blocks ATP synthesis without inhibiting electron transport by dissipating the proton gradient
DNP
Blocks electron transport and proton pumping at Complex II.
antimycin A
can be lethal because it binds to the ferric form of cytochrome oxidase and thereby inhibits oxidative phosphorylation
cyanide
mechanism for nitrite as an antidote to cyanide
Nitrite converts ferrohemoglobin into ferrihemoglobin, which also binds cyanide. Thus, ferrihemoglobin competes with cytochrome oxidase for cyanide. This competition is therapeutically effective because the amount of ferrihemoglobin that can be formed without impairing oxygen transport is much greater than the amount of cytochrome oxidase.
- higher Km
- not easily saturated
- isoenzyme of hexokinase
- ACTIVE in fed state
glucokinase
T/F
Acety Coa can be converted to pyruvate in gluconeogenesis
FALSE
Fatty acids and ketogenic amino acids cannot be used to synthesize glucose. The transition reaction is a one-way reaction, meaning that acetyl-CoA cannot be converted back to pyruvate. As a result, fatty acids can’t be used to synthesize glucose, because beta-oxidation produces acetyl-CoA.
•Acety CoA - oxidized to CO2and H2O in TCA cycle
•used to synthesize cholesterol
•used to synthesize ketone bodies
5 cofactors of alpha ketoglutarate
- Thiamine pyrophosphate (derived from thiamine)
- flavin adenine dinucleotide (derived from riboflavin)
- lipoic acid (derived from lipoic acid)
- pantothenic acid as part of Coenzyme-A (CoA)
- nicotinamide adenine dinucleotide NAD+ (derived from niacin
which of the following enzymes catalyze a rxn that yield FADH2 in citric acid cycle
succinate dehydrogenase
which TCA cycle intermediate participates in heme formation
succinyl CoA
Heme formation
•co-factor of the committed step
vitamin B6
the intermediate that links gluconeogenesis and ketogenesis in the liver
pyruvate
glucose 6 phosphate participates in all processes except •pentose phosphate pathway •gluconeogenesis •ketogenesis •glycogenolysis
ketogenesis
these processes occur inside the mitochondria except •pentose phosphate pathway •TCA cycle •beta oxidation •ketogenesis
pentose phosphate pathway
what is the mechanism of hypoglycemia in acute ethanol intoxication
conversion of PYRUVATE to lactate
branching enzyme of glycogen metabolism is
glycogen branching enzyme AKA
amylo-(1,4→1,6)-transglycosylase
•branching enzyme that catalyzes the transfer of alpha-1,4-linked glucosyl units from the outer end of a glycogen chain to an alpha-1,6 position on the same or a neighboring glycogen chain.
is a state of glucose 6 phosphatase deficiency
Von Gierke’s
T/F
glycogenolysis occurs in muscle
TRUE
glycogen phosphorylase catalyzes the cleavage of glycogen to yield
glucose-1- phosphate
- ptx with deficiency of glycogen phosphorylase in the liver
- expected manifestations EXCEPT:
- hepatomegaly
- ketosis
- lactic acidosis
- marked hyperglycemia
FALSE-
•marked hyperglycemia
deficiency of glycogen phosphorylase is
Hers’ disease
glycogen storage disorder associated with hyperuricemia
Von Gierke’s disease
enzyme deficient in Von Gierke’s disease
glucose 6 phosphatase
pregnant woman with classic galactosemia
•at risk for
premature ovarian failure
High fructose in diet is unhealthy because if is metabolized faster than glycose because it bypasses step catalyzed by
phosphofructokinase 1
- night sweats and tremors after fruit juice ingesiton
- (+) fructose in urine
- enzyme deficieny?
aldolase A
metabolic consequences of aldolase A deficiency
- INCREASE FRUCTOSE 1 phosphate levels
- hyperuricemia
- allosteric inhibition of glycogen phosphorylase
- depletion of ATP
which sugar contribute to cataract formation
sugar alcohol
which causes flatulence in lactose intolerance
bacteria in the gut
the main FATTY ACID in coconut milk
lauric acid
trans fats are manufactured by altering SATURATED fats usig
hydrogenation
end product of FATTY ACID synthsis
palmitic acid
what is the mechanism behind FATTY LIVER in chronic alcohol use
inc ÎÎ NADH prevents fatty acid oxidation forming triacylglycerols
ketone bodies
acetone
acetoacetate
beta hydroxybutyrate
steroid nucleus has ___ carbons
17
steroid nucleus resembles this ring
phenanthrene ring
cholesterol has a side chain at position
17
the consumption of cholesterol should be only up to ___ mg per day
300 mg
WELL FED STATE ≈ effect HMG-CoA reductase
HMG-CoA reductase - dephosphorylated
fate of short and medium chain FA after digestion
absorbed in the hepatic portal vein
Apolipoprotein C-II functions in breakdown of
VLDL and chylomicrons
which apoprotein is closely associated with alzheimer’s disease due to its capacity to avidly bind to beta amyloid plagues
Apo E-4
what is the basis of intestinal expression of apo B-48 lipoprotein
tssue specific RNA editing puts a stop to apoB mRNA translation
this component is responsible for transfer of CHOLESTEROL from tissues to other lipoproteins into HDL as esterified cholesterol allowing it to function in REVERSE CHOLESTEROL TRANSPORT
LCAT
T/F
•hypothyroidism
•diabetes mellitus
•nephrotic syndrome
-all are associated with abnormal lipoprotein patterns
TRUE
what familial disorder of lipoprotein metabolism has elevated levels of LDL
type 2
which familial lipoproteinemia gives
HIGH : chylomicron and VLDL
LOW : HDL, LDL
Type 1
presents as •overproduction and increased levels of VLDL •glucose intolerance •associated with coronary heart disease •type 2 DM •obesity
familial hypertriglyeridemia
ASA given low dose for coronary artery disease exerts its beneficial effect by
inhibition of cyclooxygenase required for synthesis of THROMBOXANE
product of lipid metabolism —> platelet aggregatiion
TXA2
most basic amino acid
arginine
this enantiomer of amio acids naturally occur in proteins
L amino acids
amino acids - containign phenol ring
tyrosine
formation of GABA from glutamic acid is through
glutamic acid —» GABA
decarboxylation
which cofactor is necesary for this rxn
glutamic acid ——» GABA
decarboxylation
pyridoxal phosphate
gluthathione is synthesized in the body using
glutamate
glycine
cysteine
AA responsible for antioxidant properties of gluthatione
cysteine
AAs that participate in synthesis of muscle creatine and subsequent breakdown into creatinine EXCEPT : a. alanine b. glycine c. arginine d. methionine
a. alanine
GAM ≈ creatinine
a section of protein sufficient to perform a particular task
domain
myoglobin has ___ domain/s
1 domain
major component of most connective tissues
collagen
nitric oxide is vasodilator derived from
arginine
which mediators act on NMDA receptor
glutamate
T/F
Pregnancy is a state of negative nitrogen balance
FALSE
major process involved in metabolism of amino acids
transamination
major coenzyme for transamination to form amino acids
vit B6
AA that can be synthesized from intermediates of the TCA cycle EXCEPT
a. aspartate
b. proline
c. phenylalanine
d. glumate
phenylalanine
TCA = aspartate, proline, glutamate
glucogenic amino acids
Alanine Arginine Asparagine Aspartic acid Cysteine Glutamic acid Glutamine Glycine Histidine Methionine Proline Serine Valine
Amino acids that are both glucogenic and ketogenic
Amino acids that are both glucogenic and ketogenic (mnemonic "PITTT"): Phenylalanine Isoleucine Threonine Tryptophan Tyrosine
ketogenic amino acids
leucine
lysine
Methionine can be metabilized and enter into TCA cycle as this intermediate
succinyl choline
in methylmalonic acidura there is failure to metabolize this amio acids :
•methionine, threonine, isoleucine and valine;
M, T, I, V
•as a result methylmalonic acid builds up in the blood and tissues.
an allosteric activator making carbamoyl phosphate 1 active only with its presence
N-acetyl-glutmate
direct nitrogen donors in ureal cycle
aspartate
ammonia
MAJOR nitrogen source for urea synthesis
glutamate
hyperammonemia type 1 is enzyme deficiency of
carbamoyl phosphate synthase 1
what is considered the most common urea cycle disorder
ornithine transcarbamylase deficiency
the metabolic intermediate linking urea cycle to the TCA cycle
fumarate
what happens to amino acid metabolism in uncontrolled DM
ÎÎ transamination rxns
which among the following is considered the most severe of the urea cycle disorders
carbamoyl phosphate synthase 1 deficiency
- newborn - upon delivey, suddenly develops: •irritability, lethargy, hypothermia, and intermittent apnea
- lab examination: ÎÎ ammonia levels, ÎÎ citrulline
- what enzyme is deficient
argininosuccinate synthetase
- 2 day old - born healthy and without complications
- 2nd day of life : vomiting, lethargy, hypothermia, feeding poorly, •inc RR, hepatomegaly
- BUN, ÎÎ ammonia , ÎÎargininosuccinic acid both urine and blood
•what enzyme is deficient
ariginosuccinate lyase
what enzyme deficiencies can lead to phenylketonuria
- phenylalanine hydroxylase
- tetrahydrobiopterin
- dihydrobiopterin reductase
in Maple Syrup Urine Disease, which amino acids could not be metabolize
- valine
- leucine
- isoleucine
LIV
which enzyme is deficient in MSUD
α-keto acid dehydrogenase
- infant - sweet, smeling urine, vomiting, lethargy, hypoglycemia
- most likely disease condition
branch chain α-ketoacid dehydrogenase deficiency
alkaptonuria prevents breaking down 2 amino acids, namely
Tyrosine
and
phenylalanine
alkaptonuria results in build-up of ths chemical
homogentisic acid
gene involved in alkaptonuria
HGD gene - code for homogentisate oxidase
what disease caused deficiency of Porphobilinogen deaminase (hydroxymethylbilane synthase, or uroporphyrinogen I synthase)
acute intermittent porphyria
which enzyme:
•hydrolysis of peptide bonds adjacent to aromatic, branched-chain mino acids, methionine
pepsin
All of the following substances are implicated to ÎÎ appetite except
a. orexin
b. NPY
c. AgRP
d. GLP-1
d. GLP-1
all substances are implicated to dec appetite except :
a. alpha MSG
b. CART
c. serotonin
d. cannabinoids
d. cannabinoids
the major target priority organs that utilize glucose during fasting or starvation are
brain and RBC
what does a low carb, moderate fat. high protein diet do ≈ insulin
less than normal insulin response
main fuel reserve of the body
adipose tissue triacylglycerol
this is the principal site of metabolism of branched chain amino acids
skeletal muscle
this system can serve as energy reservoir for for short term demands of muscle metabolism
phosphocreatinine system
liver glycogen stores are depleted within ___ of fasting
18-24 hours of fasting
All of the ff hormones promote LIPOLYSIS except
a. ACTH
b. GH
c. Vasopressin
d. insulin
insulin
in times of starvation, fats can be source of energy at the same time glucose through which of the ff intermediates
a. glycerol
b. propionyl CoA
fasting for 24 hours
principal source of energy
glycogenolysis
during last part of 2nd day fsting, what is major source of energy
gluconeogenesis
what is the predoinant soruce of energy for the brain after 48 hours of fasting
ketone bodies
In fasting ≈ phosphorylated /dephosphorylated •pyruvate dehydrongenase : •glycogen phosphorylase: •glycogen synthase: •acetyl-co carboxylase :
- pyruvate dehydrongenase : phosphorylated
- glycogen phosphorylase: phosphorylated
- glycogen synthase: INHIBITED
- acetyl-co carboxylase : phosphorylated
- type 1 diabetes patient
- diarrhea x 3 days
- skipped insulin doses due to lack of appetite
- glucose was 400
- urine ketones 1+
•acetyl coa carboxylase is ____
phosphorylated
- type 1 diabetes patient
- diarrhea x 3 days
- skipped insulin doses due to lack of appetite
- glucose was 400
- urine ketones 1+
•ketones detected in this patient through urine via the nitroprusside test is predominantly
acetoacetate
- type 1 diabetes patient
- diarrhea x 3 days
- skipped insulin doses due to lack of appetite
- glucose was 400
- urine ketones 1+
effect on
•HMG-CoA synthase
•HMG-CoA lyase
- HMG-CoA synthase
- HMG-CoA lyase
both active
•patient received insulin infusion
≈ effect on PFK-1
PFK-1 ≈ dephosphorylated
•a patient skips dinner everyday, what is expected when she wakse up before bfast
effect on glycogen phosphorylase
glycogen phosphorylase is phosphorylated
effect of 3 days fasting on •HMG-CoA reductase •HMG -coa synthase •pyruvate carboxylase •acetyl coa carboxylase
- HMG-CoA reductase - phosphorylated
- HMG -coa synthase - activated
- pyruvate carboxylase - stimulated
- acetyl coa carboxylase -phosphorylated
hormone least active during 3 days fasting
insulin
glucagon effect on glycogen phosphorylase
phosphorylated
drinking coffee ≈ effect on glycogen phosphorylase
phosphorylated
fatty acid synthesis
cofactor
biotin
VITAMIN B 12 dependent enzymes
- methylmalonyl coa mutase
- leucine aminomutase - converts L leucine to B leucine
- methionine synthase
which among the ff does nt need vit b12 for its pathway
a. isoleucine
b. leucine
c. valine
d. methionine
b. leucine
vitamin that is considered a hormone
vit D
which micronutrient is considered an antioxidant
a. tocopherol
b. magnesium
c. selenium
d. vitamin D
A. tocopherol
which vitamin can be synthesized from the body from a specific amino acid
vit b3 (tryptophan)
in rxn catalyzed by dopamie B-hydroxylase, what is the cofactor needed
vit C
in rxn catalyzed by dopamie B-hydroxylase, what is the product of above rxn
norepinephrine
All ÎÎÎ absorption of iron except
a. heme form of iron
b. vit C
c. alcohol
d. NOTA
d. NOTA
effects of vit D
- ÎÎ bone resorption
- ÎÎ dietary absorption of phosphate
- dec calcium levels
- dec PTH levels
inhibit bone resorption
calcitonin
what is the rate limitng enzyme of de novo pyrimidine sythesis
carbamoyl phosphate synthetase II
a single turn of human DNA has __ base pairs
10
predominant form of DNA in physiologic conditions
B
DNA polymerase synthesizes DNA in __ direction
5’ to 3’
this enzyme relieve torsional strain produced during DNA unwinding
topoisomerase
RNA dependent DNA polymerase that adds DNA to 3’ end of chromosomes to prevent loss of genetic material with every duplication
telomerase
the CCA terminal of the tRNA is found in the
acceptor arm
which type of RNA comprise majority of cellular RNA , 70%
ribosomal RNA
capped by 7-methylguanosine triphosphate group in mRNA functions to
recognition of mRNA in TRANSLATION
enzyme involved with synthesizes mRNA
RBA polymerase II
RNA product is synthesize in __ direction
5’ to 3’
termination of RNA synthesis in BACTERIA is signaled by
rho factor
RNA polymerase I catalyzes the transcription of
ribosomal RNA
in this mutation, adenine base was mistakenly substituted for a guanine base
G <=> A
transition
descriptions of genetic code
degenerate
commaless
universal
feature of genetic code stating most AA are coded by multiple codons
degenerate
codons UUC and UUU code for phenlyalanine
this displays
degeneracy
this feature of genetic code allows translation of the same amino acid despite having a different codon
redundant
most AA are coded by multiple codons except for :
a. methionine
b. cysteine
c. alanine
d. valine
a. methionine
the tRNA wobble effect leads to which of the ff DNA mutations
silent
Duchenne muscular dystrophy is example of which DNA mutation
frameshift
method used to detect a specific DNA segment of sequence
a. western blot
b. southern
c. eastern
d. nothern
southern blot
substances added to natural gas to make it smell
mercaptan
MOA of bolulinum toxin
cleaves SNARE proteins, prevening neurosecretory vesicle fusion