Which enzyme is responsible for the initial step of transamination in amino acid metabolism?

A Aspartate transaminase ✓
B Alanine transaminase
C Glutamate dehydrogenase
D Pyruvate kinase

Explanation

Aspartate transaminase catalyzes the transfer of an amino group from aspartate to α-ketoglutarate, initiating the process of transamination.

Mnemonic

'Aspartate' starts with 'A', like 'amino' group transfer

Source

Nelson et al., Lehninger Principles of Biochemistry
Protein Metabolism Biochemistry Amino Acid Metabolism Hard MEDICAL Confidence: high