Bioenergetics

Question 1

Entropy

Answer 1

randomness associated with a given system.

Question 2

Enthalpy

Answer 2

measure of heat content (thermodynamic potential) of a system.

Question 3

Free energy

Answer 3

the amount of thermodynamic energy in a system that can be converted into work at a given temperature and pressure.

Question 4

High energy compounds

Answer 4

compounds with bonds that release greater than 7 kcal/mol of energy when broken (∆G= -7; chemical energy of greater than 7 kcal/mol)

Question 5

Oxidation-reduction reaction:

Answer 5

a chemical reaction involving the transfer of electrons away from one or more compounds (the oxidized compounds) to one or more other compounds (the reduced compounds).

Question 6

First Law of Thermo

Answer 6

Energy conservation (cannot be created or destroyed, only converted)

Question 7

Second Law of Thermo

Answer 7

The entropy of the universe is constantly increasing. (This means that in any given set of reactions that occur simultaneously in a system, the overall entropy of the system must increase.)

Question 8

If the reaction is favorable, what is the sign of the ∆G?

Answer 8

Negative ∆G is spontaneous

Question 9

If the reaction is exothermic, what is the sign of the ∆H?

Answer 9

Negative ∆H is exothermic

Question 10

If the reaction is endothermic, what is the sign of the ∆H?

Answer 10

Postive ∆H is endothermic

Question 11

If the reaction is entropically and enthalpically favorable, what are the signs for ∆H and ∆S?

Answer 11

Negative ∆H and Positive ∆S lead to a more negative ∆G and a more favorable reaction. ∆G = ∆H - T∆S

Question 12

Entropy of Glucose breakdown?

Answer 12

Glucose + 6O2 -> 6CO2 + 6 H20 This means that 7 molecules goes to 12 molecules. More disorder is positive entropy.

Question 13

If the reaction is favorable by Redox Potential (∆E), what sign does it have?

Answer 13

Postiive ∆E is spontaneous; ∆G = -nF∆E

Question 14

An electronegative molecule has what type of E°? Positive/Negative?

Answer 14

Electronegativity leads to a Highly Positive E°

Question 15

An electropositive molecule has what type of E°? Positive/Negative?

Answer 15

Electropositivity leads to a Highly Negative E°

Question 16

If Keq is&raquo_space;1, is the reaction going forwards, backwards, or at equillibrium?

Answer 16

Keq&raquo_space;1 = ∆G «0 = Spontaneous Forward

Question 17

If Keq is «1, is the reaction going forwards, backwards, or at equillibrium?

Answer 17

Keq <>0 = Spontaneous Backwards

Question 18

If Keq is equal to 1, is the reaction going forwards, backwards, or at equillibrium?

Answer 18

Keq = 1 = ∆G = 0. The reaction is at equilibrium.

Question 19

What are the Bonds in Acetyl-CoA?

Answer 19

Thioester Bonds

Question 20

What are the Bonds in ATP?

Answer 20

Phosphoanhydride P-O-P Bonds

Question 21

What are the Bonds in Phosphocreatine

Answer 21

P-N Bonds

Question 22

What are the Bonds in Phosphoenolpyruvate?

Answer 22

C-O-P Bonds

Question 23

What type of bonds link DNA and RNA along a chain?

Answer 23

Phosphodiester bonds

Question 24

Why can lipids store more energy than carbohydrates?

Answer 24

The central carbon on of lipids has a greater number of valence electrons.

Question 25

Gout is caused by an accumulation of what what chemical compound?

Answer 25

purines

Question 26

If we know the Electron Energy given off by two reactions, (such as the reduction of acetaldehyde to ethanol and the reduction of NAD+ to NADH), how can we find the ∆E°?

Answer 26

Electron Acceptor - Electron Donor = ∆E°