Q1. Two intracellular molecules X and Y are both normally synthesized at a constant rate of 1000 molecules per second per cell. Molecules X is broken down slowly: each molecule of X survives on average for 100 seconds, Molecule Y is broken down 10 times faster, each molecule of Y services on average for 10 seconds.

Compute how many molecule of X and Y the cell contains at any time.

Q2. The breakdown of sucrose into the simple sugars fructose and glucose is an exergonic reaction. Sucrose is quite stable, and left on its own at room or even human body temperature, breakdown occurs very slowly. The enzyme sucrase catalyzes conversion of sucrose to glucose and fructose, increasing the reaction rate as a minimum one-million-fold. How does the net amount of energy released during the breakdown of sucrose compare between spontaneous reactions and catalyzed by sucrase?