Which of the following is a correct association A kinase act

Which of the following is a correct association? A. kinase activity and the addition of a tyrosine B. phosphodiesterase activity and the removal of phosphate groups C. GTPase activity and hydrolysis of GTP to GDP D. phosphorylase activity and the catabolism of glucose E. adenylyl cyclase activity and the conversion of cAMP to AMP What is a chromide? A. a replicated chromosome B. a chromosome in G_1 of the cell cycle C. a chromosome found outside the nucleus D. a special region that holds two centromerers together E. another name for the chromosomes found in genetics

Solution

49. The correct answer is option C.

Kinase activity adds phosphate, not tyrosine. Phosphodiesterases break cyclic nucleotides such as cAMP, cGMP, etc. by cleaving the phosphodiester bond. Phosphorylases are involved in catabolism of glucans such as glycogen; catabolism of glucose requires phosphotransferase (kinase). Adenylyl cyclase activity synthesizes cAMP from ATP, not the other way round. Therefore, only option C is correct.

50. The correct answer is option A.

Before cell division physically takes place, the chromosomes are replicated into two identical copies (\"sister chromatids\") that exist in highly condensed form joined at the centromere; each copy is called a chromatid.

All other options are factually incorrect.