Bioenergetics.

Question 1

What are bioenergetics?

Answer 1

Bioenergetics predicts whether a process will occur or not.

Question 2

What are kinetics?

Answer 2

Kinetics predicts how quickly or how likely a reaction is to occur.

Question 3

What is the Km of a reaction?

Answer 3

The concentration of substrate when an enzyme is at half Vmax.

Question 4

What is the Vmax of a reaction?

Answer 4

The maximum velocity or rate at which an enzyme can work.

Question 5

The kinetics of a reaction are primarily concerned with what biological reactions?

Answer 5

Enzymatic reactions.

Question 6

What aspects of a reaction are bioenergetics concerned with?

Answer 6

The energy needed for a reaction to occur.

Whether a reaction will occur spontaneously

Question 7

Knowing the bioenergetics allows us to determine what about a biological reaction?

Answer 7

Whether it will occur naturally or not.

Question 8

What is the 1st law of thermodynamics?

Answer 8

The energy of the universe is constant.

Question 9

What is the 2nd law of thermodynamics?

Answer 9

The entropy (disorder) of the universe is increasing.

Question 10

How do the first 2 laws of thermodynamics affect biological reactions?

Answer 10

Whether a reaction will occur naturally or not is dependent upon the 1st 2 laws of thermodynamics.

Question 11

What does the Gibbs free energy equation allow us to calculate?

Answer 11

The change in free energy.

Question 12

What does the change in free energy depend on?

Answer 12

The change in enthalpy and the change in entropy.

Question 13

What is entropy?

Answer 13

A measure of disorder.

Question 14

What is enthalpy?

Answer 14

The heat released or absorbed in a reaction.

Question 15

What is the Gibbs free energy equation?

Answer 15

ΔG = ΔH - T ΔS.

Where ΔG = The change in free energy.

ΔH = The change in enthalpy.

T = Temperature.

ΔS = The change in entropy.

Question 16

What does delta G represent?

Answer 16

The change in free energy.

Question 17

What is the free energy in a reaction?

Answer 17

The amount of energy that is available to do work.

Question 18

As a reaction approaches equilibrium, what will happen to delta G?

Answer 18

It will start to approach 0.

Question 19

What is delta G when a reaction is at equilibrium?

Answer 19

0.

Question 20

What will dictate whether a reaction will occur or not?

Answer 20

The amount of free energy that is available.

Question 21

What is delta G dependent on?

Answer 21

The concentrations of products and reactants.

Question 22

What is delta ΔG°?

Answer 22

ΔG° predicts the change in free energy under standard conditions.

Question 23

How does the addition of ΔG° to the Gibbs free energy equation change the overall equation?

Answer 23

ΔG = ΔG° + RT ln (B/A).

Where ΔG = The change in free energy.

ΔG°= The change in free energy under standard conditions.

R = The gas constant.

T = Temperature.

B = Products.

A = Reactants.

Question 24

What are standard conditions for ΔG°?

Answer 24

1 mol/litre.

Question 25

What is the other name that ΔG° is known as?

Answer 25

The standard free energy change.

Question 26

Can ΔG can be different to the amount of ΔG°?

Answer 26

Yes.

Question 27

What does ΔH represent?

Answer 27

The change in enthalpy.

Question 28

What does ΔS represent?

Answer 28

The change in entropy.

Question 29

Can enthalpy or entropy be used to determine whether a reaction will be spontaneous or not?

Answer 29

No.

Question 30

What happens to the reactants in a reaction?

Answer 30

They will react to form products.

Question 31

Do reactants contain more energy than products?

Answer 31

Yes.

Question 32

What kind of ΔG must a reaction have if it is spontaneous?

Answer 32

A negative ΔG.

Question 33

What kind of ΔG must a reaction have if it is not spontaneous?

Answer 33

A positive ΔG.

Question 34

Do spontaneous reactions need any energy?

Answer 34

No.

Question 35

Are exergonic reactions spontaneous or non spontaneous?

Answer 35

They are spontaneous.

Question 36

Do exergonic reactions release energy?

Answer 36

Yes.

Question 37

What ΔG will exergonic reactions have?

Answer 37

Negative.

Question 38

If a reaction has a positive ΔG, will the products or reactants contain more energy?

Answer 38

The products will have more energy.

Question 39

Will a reaction with a positive ΔG be spontaneous or non spontaneous?

Answer 39

Non spontaneous.

Question 40

Will a reaction with a positive ΔG be endergonic or exergonic?

Answer 40

Endergonic.

Question 41

Does an endergonic reaction require energy before it can take place?

Answer 41

Yes.

Question 42

Is there a change in concentration of reactants and products when a reaction is at equilibrium?

Answer 42

No.

Question 43

When will a spontaneous reaction stop?

Answer 43

When equilibrium has been reached.

Question 44

If the the free energy of A to B is equal to the free energy of B to A, what kind of reaction is it?

Answer 44

A reaction at equilibrium.

Question 45

What is a coupled reaction?

Answer 45

An overall reaction that is made up of a series of steps of sub reactions.

Question 46

What is a common intermediate?

Answer 46

This is an intermediate in a coupled reaction that takes part in all of the steps in a reaction.

Question 47

What is the common intermediate in the following reaction? Reaction 1. A + B → C + D. Reaction 2. D + X → Y + Z.

Answer 47

D.

Question 48

How do you calculate ΔG for a coupled reaction?

Answer 48

You add the delta Gs of both reactions together.

Question 49

If a coupled reaction is made up of a positive ΔG reaction and a negative ΔG reaction will it be spontaneous?

Answer 49

Only if the overall reaction has a negative ΔG.

Question 50

Which bonds in ATP have the most energy?

Answer 50

The first 2 phosphate bonds.

Question 51

What is ATP made up of?

Answer 51

An adenosine which is bound to 3 inorganic phosphates.

Question 52

What is the ΔG of the 1st 2 phosphate groups in ATP?

Answer 52

-7300 cal/mol.

Question 53

What is the ΔG of the 3rd phosphate group ATPs in ATP?

Answer 53

-4000 cal/mol.

Question 54

What is the ΔG of ATP - ADP?

Answer 54

-7300 cal/mol.

Question 55

What is the ΔG of ADP - AMP?

Answer 55

-7300 cal/mol.

Question 56

What is the ΔG of AMP - adenosine?

Answer 56

-4000 cal/mol.

Question 57

How can we manipulate a reaction to give a -ΔG?

Answer 57

By manipulating the concentrations of reactants and products changing a positive ΔG to a negative ΔG?