Multiple Choice QuestionsWhich one of the following enzymes is responsible for the conversion of norepinephrine to epinephrine?
Catecholamine-O-methyltransferase
Phenylalanine-N-methyltransferase
DOPA decarboxylase
Monoamine oxidase
A.
Catecholamine-O-methyltransferase
Phenylalanine-N-methyltransferase (PNMT) is an enzyme found in the adrenal medulla that converts nor-epinephrine to epinephrine. It is a protein whose encoding gene is found on chromosome 17 in humans. It catalyses the transfer of a methyl group from SAM (S-adenosyl-L-methionine) which is a factor to nor-epinephrine, converting it into epinephrine.
Medullary rays are tissues made up of
phloem parenchyma
xylem parenchyma
sieve tube
sclerenchyma
An allosteric inhibitor of the enzyme acts by binding to the
substrate
product
catalytic site of the enzyme
non-catalytic site of the enzyme
Which one of the following matching pairs is incorrect?
Mollusca - Pseudocoel
Cnidaria - Nematocyst
Annelida - Chloragogen cells
Echinodermata - Water vascular system
Which one of the following matching pairs is incorrect?
Shell fish - Pisces
Silver fish - Arthropoda
Cuttle fish - Mollusca
Star fish - Echinodermata
The hormone that stimulates the release of pancreatic juice is
secretin
glucagon
inhibin
insulin
Nitrogenase enzyme is a
magnesium-iron protein
molybdenum-iron protein
iron-copper protein
nickel-iron protein
Necrosis (die-back) ofthe tip of young leaves is caused due to the deficiency of
iron
manganese
zinc
copper
Guttation is a process of loss of water in
liquid form containing dissolved minerals
liquid form without dissolved minerals
vapour form with minerals
vapour form without minerals
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