Metal ions used by many enzymes to change their non-functional active sites to functional ones are called? A) Co-enzymes B) Apo-enzymes C) HoloenzYmes D) Co-factor Related MCQs: It is a story of two non-functional batches of ….. armoured cars? The sarcoplasmic reticulum in the muscle cells acts as a store of ……. ions? Which of the following is a non-metal that remains in liquid form at room temperature? Tall, slender athletes play basketball while shorter, huskier ones play football because of?