Bioenergetics LO

Question 1

Define Entropy

Answer 1

randomness associated with a given system

Question 2

Define enthalpy

Answer 2

measure of heat content (thermodynamic potential) of a system

Question 3

Define 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

Define high energy compounds

Answer 4

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

Question 5

Define oxidation-reduction reaction

Answer 5

a chemical reaction involving the transfer of electrons away from oxidized compounds to reduced compounds

Question 6

What is the 1st law of thermodynamics?

Answer 6

energy conservation (energy cannot be created or destroyed, only converted to other forms)

Question 7

what is the 2nd law of thermodynamics?

Answer 7

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

Question 8

Describe kinetic energy

Answer 8

energy of motion (radiant, thermal, mechanical, electric)

Question 9

Describe potential energy

Answer 9

energy stored within a system due to configuration or position, can be converted to kinetic energy to perform work

Question 10

describe radiant energy

Answer 10

carried in photons from sun, the ultimate source of all forms of energy in living systems

Question 11

describe thermal energy

Answer 11

kinetic energy of molecules (molecular translation, rotation, vibration, e- spin, translation, and nuclear spin) proteins function at an optimal thermal energy

Question 12

describe mechanical energy

Answer 12

potential and kinetic energy within a mechanical system, discussed within the confines of cellular movement of charge particles down gradients of electric potential

Question 13

describe electric energy

Answer 13

energy movement of charged particles down gradients of electrical potential

Question 14

describe chemical energy

Answer 14

energy stored in chemical bonds

Question 15

how do you calculate deltaG?

Answer 15

∆G0 + (RT * ln [PRODUCTS]/[REACTANTS])

Question 16

how to you calculate deltaGprime?

Answer 16

• RT ln (Keq)

Question 17

how do you calculate deltaG?

Answer 17

∆H – (T * ∆S )

Question 18

what is the spontaneity of this reaction? ∆G<0

Answer 18

spontaneous

Question 19

what is the spontaneity of this reaction? ∆G>0

Answer 19

not spontaneous

Question 20

what is the spontaneity of this reaction? ∆G=0

Answer 20

at equilibrium

Question 21

what does positive entropy do to change the spontaneity of a reaction? (hint use ∆G = ∆H – T ∆S)

Answer 21

increases the spontaneity of the reaction (decreases ∆G)(-∆H = exothermic)

Question 22

what does a negative entropy do to change the spontaneity of a reaction? (hint use ∆G = ∆H – T ∆S)

Answer 22

decreases the spontaneity of the reaction (increases ∆G) (∆H = endothermic)

Question 23

what does a negative enthalpy do to change the spontaneity of a reaction? (hint use ∆G = ∆H – T ∆S)

Answer 23

increases the spontaneity of the reaction (decreases ∆G)

Question 24

what does a positive enthalpy do to change the spontaneity of a reaction? (hint use ∆G = ∆H – T ∆S)

Answer 24

decreases the spontaneity of the reaction (increases ∆G)(+∆S = increased entropy)

Question 25

how do you calculate ∆E for a reaction?

Answer 25

subtract the Eo of the electron donor from the Eo of the electron acceptor.

Question 26

when is Eo of a molecule high?

Answer 26

when the molecule is more electronegative

Question 27

when is Eo of a molecule more negative?

Answer 27

when the molecule is more electropositive

Question 28

what equation do you use to calculate gibbs free energy using redox potential?

Answer 28

∆G = -nF∆E
n = #of electrons transferred
F = Faraday's constant
∆E = difference in reduction potential in volts

Question 29

what does coupling of a reaction mean?

Answer 29

the SUM of gibbs free energy of 2 or more reactions to determine the spontaneity of the reaction (ex. +∆G can be spontaneous if paired with -∆G of greater absolute value)

Question 30

What is the high energy bond in acetyl Co-A?

Answer 30

thioester bonds C-S

Question 31

what is the high energy bond in ATP?

Answer 31

phosphoanhydride bonds (P-O-P)

Question 32

what is the high energy bond in phosphocreatine?

Answer 32

P-N

Question 33

what is the high energy bond in phosphoenolpyruvate?

Answer 33

C-O-P

Question 34

What is considered high yield currency in bioenergetics?

Answer 34

bonds that are easy to use, break, and reform.