Thermodynamics and Bioenergetics

Question 1

Describe the first law of thermodynamics

Answer 1

Energy can neither be created or destroyed (but it can be changed from one form to another or transported from one region to another)

Question 2

Describe the second law of thermodynamics

Answer 2

Any spontaneous process must cause the entropy of the universe to increase

Question 3

Define state variable/state function

Answer 3

a property that is independent of the history of the system

Question 4

Define enthalpy

Answer 4

the heat change of a reaction at constant pressue

Question 5

Define entropy

Answer 5

a state function that measures the degree of disorder or randomness of a system

Question 6

Define free energy

Answer 6

a quantitative measure of the driving force of a process at constant temp and pressure

describes how much energy is available in a system for mechanical work to take place

Question 7

Endergonic reaction

Answer 7

delta G is >0

The forward process is energetically unfavourable. The reverse process proceeds spontaneously.

Question 8

Exergonic reaction

Answer 8

delta G is <0

The forward process in energetically favourable. The forward process proceeds spontaneously.

Question 9

The relationship between enthalpy and entropy and free energy

Answer 9

For all chemical and physical processes, the interplay between delta H and T delta S determines the favourable reaction (whether delta G is negative or positive)