Which 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.
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
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
