#Question id: 2288
#Unit 2. Cellular Organization
Proteins lacking a signal peptide sequence will probably found in
#Question id: 19180
#Unit 13. Methods in Biology
#Question id: 643
#Unit 1. Molecules and their Interaction Relevant to Biology
The hydrolysis of lactose is catalysed by b-galactosidase as given below
Which of the following could be correct mechanism for this hydrolysis reaction?
A. Nucleophilic attack by the carboxylate group of Glu/Asp on the C-1 carbon atom of the galactose moiety within glucose, releasing glucose and forming an intermediate with the galactose linked to the enzyme through an ester linkage. Water then attacks this carbon atom, displacing the glutamate carboxylate and releasing galactose.
B. Electrophilic attack by the carboxylate group of Glu/Asp on the C-1 carbon atom of the galactose moiety within glucose, releasing glucose and forming an intermediate with the galactose linked to the enzyme through an ester linkage. Water then attacks this carbon atom, displacing the glutamate carboxylate and releasing galactose.
C. Nucleophilic attack by the carboxylate group of Lys/Arg/His or bivalent cation on the C-1 carbon atom of the galactose moiety within glucose, releasing glucose and forming an intermediate with the galactose linked to the enzyme through an ester linkage. Water then attacks this carbon atom, displacing the glutamate carboxylate and releasing galactose.
#Question id: 919
#Unit 1. Molecules and their Interaction Relevant to Biology
Carnitine is:
#Question id: 15256
#Unit 2. Cellular Organization