Question

• Opposite charges attract; like charges repel.
• Like dissolves like.
• “Stable” means “low energy” and unreactive, while “unstable” means “high energy” and reactive; and all things spontaneously become more stable over time (unless there is an input of energy), and in becoming more stable they release energy.

Explain how one or more of those principles apply to each of the following:

1. Phosphorylation/dephosphorylation is often used to change enzyme functionality. (2.5 points)
2. ATP is a “high energy” molecule. (2.5 points)

answer the questions by using the above principles such ATP is high energy becuase it is unstable

Answer 1

1. The conformational change to an enzyme caused by the addition of one or more phosphate groups can activate or inhibit the enzyme. For example, phosphorylation of the enzyme glycogen synthetase changes the enzyme's shape and reduces its activity. Thus phosphorylation alters the structural conformation of a protein, causing it to become activated, deactivated, or modifying its function.

2. ATP is an unstable molecule which hydrolyzes to ADP and inorganic phosphate when it is in equilibrium with the water. The high energy of this molecule comes from the two high-energy phosphate bonds. The bonds between phosphate molecules are called phosphoanhydride bonds