CH 1.3: Physical Foundations

Why do concentrations of molecules such as hemoglobin and glucose stay constant?

Rate of synthesis or intake = Rate of breakdown, consumption, or conversion

What is a system?

All the constituent reactants and products, the solvent that contains them, and the immediate atmosphere

What is the a universe?

The system and its surroundings

What is an isolated system?

System exchanges neither energy or matter with its surroundings

What is a closed system?

System exchanges energy but not matter with its surroundings

What is an open system?

System exchanges both energy and matter with its surroundings

What type of system are living organisms?

Open

How do organisms get energy?

• Take up chemical fuels from the environment and oxidizes them

• Absorbs energy from sunlight

What is the first law of thermodynamics?

Conservation of energy

In any physical or chemical change, the total amount of energy in the universe remains constant, although the form of the energy may change

What energy can cells interconvert?

• Chemical

• Electromagnetic

• Mechanical

• Osmotic

When a cell doesn’t have enough energy, what happens?

Goes from steady state towards equilibrium with its surroundings, causing the cell to decay

What are oxidation-reduction reactions?

One reactant is oxidized as another is reduced

What does it mean to be oxidized?

Loses electrons

What does it mean to be reduced?

Gains electrons

What is the second law of thermodynamics?

Randomness in the universe is constantly increasing.

What is entropy (s)?

Randomness or disorder of components of a chemical system

What is G?

Gibbs free energy

What is enthalpy (H)?

The heat of a system

What does it mean if delta H is negative?

Releases heat/ exothermic

What does it mean if delta H is positive?

Absorbs heat/ endothermic

What does it mean if delta S is positive?

Randomness increases

What does it mean if delta S is negative?

Randomness decreases

What is the Gibbs free energy equation?

Delta G = Delta H - (T)*(Delta S)

What does it mean if Delta G is negative?

Energy is released

What does endergonic mean?

Requiring energy

What does exergonic mean?

Releasing energy

What Delta G is thermodynamically favorable?

Delta G is negative