Thermodynamics

Question 1

What is the first law of thermodynamics?

Answer 1

Law of conservation of energy

Question 2

What is the second law of thermodynamics?

Answer 2

Entropy

Question 3

What is Gibbs Free Energy?

Answer 3

Energy available to do useful work

Question 4

What is Enthalpy (H)?

Answer 4

A measure of heat energy that reflects bond formation and breakages

Question 5

If delta H is greater than 0, the reaction is ___?

Answer 5

Endothermic - heat is absorbed

Question 6

If delta H is less than 0, the reaction is ___?

Answer 6

Exothermic - heat is released

Question 7

What is the equation for free energy change during a chemical reaction?

Answer 7

delta G = delta H - T x delta S

Question 8

When entropy increases, what is the sign for S?

Answer 8

Postitive

Question 9

If the change is enthalpy is negative, is heat released or absorbed?

Answer 9

Released

Question 10

When is T negative?

Answer 10

Never. It is in Kelvin

Question 11

In bioenergetics which reaction is thermodynamically favorable, endergonis or exergonic?

Answer 11

Exergonic

Question 12

What do endergonic reactions require?

Answer 12

An input of energy (+delta G)

Question 13

Which reaction releases energy, endergonic or exergonic?

Answer 13

Exergonic (-delta G)

Question 14

How can a thermodynamically unfavorable process be driven forward?

Answer 14

By coupling endergonic and exergonic reactions, often by coupling to the hydrolysis of ATP

Question 15

What is the equilibrium constant?

Answer 15

A ration of products/reactants

Question 16

On what does the reaction rate depend?

Answer 16

Activation energy

Question 17

Overall free energy change is ___.

Answer 17

Additive

Question 18

Overall equilibrium constant is ___.

Answer 18

Multiplicative

Question 19

How much ATP is in the body?

Answer 19

100g

Question 20

How much ATP does a resting human consume per day?

Answer 20

40 kg

Question 21

How fast is ATP typically consumed?

Answer 21

Usualy within 1 minute of formation

Question 22

Catabolic processes are ___ and ___

Answer 22

Exergonic

Oxidative

Question 23

Anabolic processes are ___ and ___.

Answer 23

Endergonic

Reductive

Question 24

Catabolic processes, being oxidative, produce what?

Answer 24

NADH/NADPH

Question 25

Anabolic processes are reductive, meaning they use what?

Answer 25

NADH/NADPH

Question 26

Oxidation is ___

Answer 26

Loss of electrons

Question 27

Reduction is ___

Answer 27

Gain of electrons

Question 28

What drives redox reactions?

Answer 28

Electron transfer

Question 29

What are the 4 ways that electrons are transferred?

Answer 29

1. Directly as electrons
2. As hydrogen atoms
3. As a hydride ion
4. Direct combination with oxygen

Question 30

What is the oxidation state of nitrous oxide? (N2O)

Answer 30

+1

Question 31

What is the oxidation state of nitric oxide?

Answer 31

+2

Question 32

Biological redox is largely based on which amino acid?

Answer 32

Cysteine

Question 33

What are the most common biological redox partners?

Answer 33

NADH

FADH2

Question 34

Enzymes that catalyze biological redox reactions are called what?

Answer 34

Dehydrogenases

Question 35

What is an oxidizing agent?

Answer 35

An electron accepting molecule

Question 36

What is a reducing agent?

Answer 36

An electron donating molecule

Question 37

In a redox couple, which molecule has the greater reduction potential and will therefore get reduced?

Answer 37

The molecule with the more positive E value

Question 38

Are NADH and NADPH protein bound?

Answer 38

No - they are freely soluble