Ch 8

ATP and EnergyDr. Laurie Solis

ATP’s bonds are broken through hydrolysis This releases energy ATP ADP This reaction is exergonic: reactions that occur

spontaneously and result in a loss of energy Example: Cellular respiration

(C6H12O6+6O26CO2+ 6H2O Another way to look at the above equation is

through the caloric loss of calories: DG= -686 kcal

ATP

The process of ATP being broken down simply

through hydrolysis is: ATP + H2O ADP + (P) Another way to look at it in terms of loss of

calories is: DG= -7.3kcal All three of the phosphate groups in ATP are

negatively charged, which is why when hydrolysis occurs, a lot of energy is released.

ATP

*(P) = Inorganic Phosphate

ATP and Work

When ATP is in a test tube, it heats up the surrounding water.

This is because it is releasing free energy into the water

ATP and Work

When you shiver from the cold, shivering is using ATP hydrolysis during muscle contraction to generate heat and warm the body

Enzymes

Enzymes speed up metabolic reactions by lowering energy barriers

Enzymes are Catalysts – they make things happen

Enzymes

Let’s assume for a moment, the world did not have enzymes…

How would DNA bases break their bonds?

Molecules would have to become hot on their own

Reach a high temperature to break the bonds

Enzymes