Biochemistry Exam 1 - Thermodynamics

What is Thermodynamics?

What is Thermodynamics?

- the study of energy and its effects on matter.
- explains the exchanges between heat, energy, and work.

What are the three components of thermodynamics? What does it mean?

- Heat: A form of thermal energy
- Energy: the ability to do work
- Work: Energy given to the environment.

What is the purpose of thermodynamics?

- Tells the direction of the reaction
- Rate doesn't matter

What are the 3 types of systems? What do they do?

- Isolated: neither energy or matter is exchanged
- Closed: exchange of only energy
- Open: exchange of both energy and matter.

What is the second law of thermodynamics?

- Spontaneous reactions increase disorder.

What does the symbol (H) mean?

- Enthalpy: heat absorbed

ΔH < 0 means .....

- Heat is given off; exothermic and enthalpically driven/favored

ΔH > 0 means .....

- Heat is absorbed; endothermic and enthalpically opposed

ΔS < 0 means ....

- Disorder decreases and entropically opposed

ΔS > 0 means ....

- Disorder increases and entropically favored

ΔG < 0

- spontaneous and exergonic

ΔG > 0

- nonspontaneous and endergonic

What is the first law of thermodynamics?

- Energy is conserved
- Energy can neither be created nor destroyed

What does the symbol (U) mean?

- Potential and Internal Energy

What does the symbol (S) mean?

- Entropy: disorder

What does the symbol (G) mean?

- Gibbs Free Energy

Δq < 0

- heat is being given off (exothermic)

Δq > 0

- system absorbs heat (endothermic)

Δ w < 0

- does work on itself

Δw > 0

- does work on the surrounding

- ΔH & +ΔS

- ΔG (spontaneous) exogenic and ethalpically and entropically favored (exothermic)

+ΔH & -ΔS

+ ΔG (nonspontaneous) endergonic and ethalpically and entropically opposed (exothermic)

-ΔH & -ΔS

- Reaction is enthalpically favored but entropically opposed.
- Spontaneous only at temp. Below T= ΔH/ΔS

+ΔH & +ΔS

- Reaction is enthalpically opposed but (endothermic) entropically favored.
- Spontaneous only at temp. Above T= ΔH/ΔS