Building blocks

Question 1

what is gibbs free energy?

Answer 1

Energy of the reaction available to do work

Question 2

describe diagram of gibbs free energy vs reaction coordinate

Answer 2

Y axis is gibbs free enrgy
X axis is reaction coordinate

bac on Y axis
B is transition state
A is reactant
C is product

Question 3

What is activation energy for the reaction in terms of the diagram

Answer 3

Delta ActEnergy = b - a so transition state - reactants

Question 4

What is gibbs free energy for reaction in terms of the diagram

Answer 4

Delta G = c-a

Product - reactants

Question 5

Spontaneous reactions have what delta G

Answer 5

Negative delta G

Question 6

How can a negative delta G be given in terms of G = H - TS

Answer 6

Highly exothermic delta H, so very negative

High increase in entropy so a very positive delta S

Question 7

Is exergonic or endergonic favourable for spontaneous reaction

Answer 7

Exergonic, where delta G is negative. Free energy is released

Question 8

What is Keq and what does it describe

Answer 8

The thermodynamic equilibrium constant for the reaction. The relative concentrations of components at equilbrium

Question 9

What is the free energy equation in terms of the standard free energy change and RT

Answer 9

Delta G = Standard free energy change + RTlnQ

Question 10

What is Q the same as

Answer 10

Keq

Question 11

When delta G is 0 it is at equilibrium, what does this mean for the reaction?

Answer 11

The reaction can do no more work, no free energy change

Question 12

What are the biochemistry standard conditions

Answer 12

Well buffered aqueous solutions at pH7

Question 13

What does it mean for the aqueous solution to be at pH7

Answer 13

H+ is 10^-7
H20 is 55.5M
Mg2+ is 1mM

Question 14

Even if the standard free energy change value is positive, what can be altered to get a negative value for the free energy change?

Answer 14

Initial conditions can be altered that way the Keq can be

Question 15

How can Keq be

Answer 15

Conc of products is lower than reactants

Question 16

How can the concentrations of products be much lower than reactants? Describe 2 ways

Answer 16

1) Remove one or more of the products at a rate much faster than it is produced
2) Add reactants at a rate much faster than it is removed

Question 17

What does ATP stand for

Answer 17

Adenosine 5’triphosphate

Question 18

Describe the structure of ATP

Answer 18

3 phosphate groups, ribose, adenine base.

3 phosphate groups linked 5’ to ribose, the adenine base is then linked to 1’ribose

Question 19

What makes a nucleotide

Answer 19

Base + Sugar + Phosphate

Question 20

What makes a nucleoside

Answer 20

Base + Sugar

Question 21

How is energy released using ATP and describe the equation

Answer 21

Hydrolysis of the gamma phosphate.

ATP + H2O -> ADP + Pi (inorganic phosphate)

Question 22

Why does hydrolysis of ATP yield energy

Answer 22

Exothermic enthalphy due to the differenc ein bond energies. Entropy increase