Cell biology - Amino acid metabolism Flashcards
(40 cards)
when the a carbon atom of amino acid is assymetric it allows for two mirror image optical isomers known as..
a. E/Z
b. cis/trans
c. p/q
d. L/D
d.L/D
all amino acids can exist as one of two optical isomers except..
a. glycine
b. valine
c. serine
a.glycine
what forms of amino acids are found in human proteins
a,L
b.D
a,L
Lysine and hisitidine are bot examples of a ….
a. polar amino acid which a positive side chain
b. polar amino acid with an uncharged polar side chain
c. non polar amino acid with a non polar side chain
a.polar amino acid which a positive side chain
threonine is an example of a ….
a. polar amino acid which a positive side chain
b. polar amino acid with an uncharged polar side chain
c. non polar amino acid with a non polar side chain
b.polar amino acid with an uncharged polar side chain
valine, leucine, isoleucine,phenylalanine, methionine, and tryptophan are examples of a ….
a. polar amino acid which a positive side chain
b. polar amino acid with an uncharged polar side chain
c. non polar amino acid with a non polar side chain
c.non polar amino acid with a non polar side chain
what type of carbon skeleton is degraded to pyruvate / TCA intermediates as precursors for gluconeogenesis/ converted for storage
a. glucogenic
b. ketogenic
a.glucogenic
what type of amino acid has the carbon skeleton degraded to acetyle coA or acetoacetate for energy in krebs or converted to ketone bodies/fatty acids
a. glucogenic
b. ketogenic
b.ketogenic
phenylalanine is
a. glucogenic
b. ketogenic
c. both
c.both
what is glucogenic phenylalanine converted to by phenylalanine hydroxylase
a. tyrosine
b. acetoacetate
a.tyrosine
what is ketogenic phenylalanine converted to by phenylalanine hydroxylase
a. tyrosine
b. acetoacetate
b.acetoacetate
ketone body
cannot be syntheised to glucose
lack of phenylalanine hydroxylase means phenylalaine cant be converted to pyruvate . which form of pheylalanine does this happen to
a. glucogenic
b. ketogenic
a.glucogenic
what is formed instead of pyruvate when there is a lack of phenyl alanine hydroxylase in pku
a,pyruvate
b. acetoatate
c. phenylactate
d. phenylpyruvate
d.phenylpyruvate
then forms phenylactate and phenyllactate
how is PKU inherited?
a. autosomal recessive
b. autosomal dominant
c. x linked
d. polygenic
a.autosomal recessive
phenylalanine and which other substance accumulates a few days after birth in pku?
a,pyruvate
b. acetoatate
c. phenylactate
d. phenylpyruvate
d.phenylpyruvate
the heel prick test tests for pku and..
a. marfans
b. ehlers danlos
c. MCADD
c.MCADD
which of these is not supplemented in pku?
a. phenylalanine free amino acids
b. tyrosine
c. phenylalanine
c.phenylalanine
Which metabolic abnormality gives rise to the
serious disease phenylketonuria?
a) Homocysteine cannot be converted into
methionine
b) Phenylalanine cannot be converted into
tyrosine
c) Phenylalanine cannot be converted into alanine
d) Tyrosine cannot be converted into
phenylalanine
b) Phenylalanine cannot be converted into
tyrosine
what happens in step 1 of amino acid catabolism
a, a amino group transferred to a ketoglutarate to form glutamate/ oxidatively deaminated to ammonium
b. ammonium used to synthesize carbamoyl phosphate
c. carbamoyl phosphate and ornithine combine to form citrulline catalysed by OTC, citrulline then exported into cytosol where its converted to urea in 3 steps
a, a amino group transferred to a ketoglutarate to form glutamate/ oxidatively deaminated to ammonium
what happens in step 2 of amino acid catabolism
a, a amino group transferred to a ketoglutarate to form glutamate/ oxidatively deaminated to ammonium
b. ammonium used to synthesize carbamoyl phosphate
c. carbamoyl phosphate and ornithine combine to form citrulline catalysed by OTC, citrulline then exported into cytosol where its converted to urea in 3 steps
b.ammonium used to synthesize carbamoyl phosphate
what happens in step 3 of amino acid catabolism
a, a amino group transferred to a ketoglutarate to form glutamate/ oxidatively deaminated to ammonium
b. ammonium used to synthesize carbamoyl phosphate
c. carbamoyl phosphate and ornithine combine to form citrulline catalysed by OTC, citrulline then exported into cytosol where its converted to urea in 3 steps
c.carbamoyl phosphate and ornithine combine to form citrulline catalysed by OTC, citrulline then exported into cytosol where its converted to urea in 3 steps
what enzyme forms carbamoyl phosphate from ammonium in step 1 of the urea cycle inside the mitochondria?
a. lipoprtein lipase
b. phenylalanine hydroxylase
c. OTC
d. carbamoyl phosphate synthetase
d.carbamoyl phosphate synthetase
where does the urea cycle primarily occur
a. liver
b. kidney
c. spleen
a.liver
kidneys to lesser extent
what actalyses conversion of carbamoyl phosphate in combination with ornithine to citrulline
a. lipoprtein lipase
b. phenylalanine hydroxylase
c. OTC
d. carbamoyl phosphate synthetase
c.OTC
