Thermodynamics and Bioenergetics

In any _____ of solute in solvent, the entropy of the system increases

dissolution

A thermodynamic function that accounts for heat flow

enthalpy

The sum of all chemical reactions in the cell

metabolism

In a typical biological oxidation rxn, hydride from an alcohol is transferred to NAD+, giving:

NADH

In the process of transforming energy, living organisms increase the entropy of the

universe

Which Law of Thermodynamics states, the entropy of a perfectly crystalline material is zero at absolute zero (0K)

Third Law of Thermodynamics

Complete oxidation of reduced compounds is strongly

favorable

Change in internal energy is equal to heat plus

work

Source of energy for use and storage at the cellular level

ATP

In cells, hydrolysis rxns tend to be

spontaneous

The ultimate source of energy on Earth

sunlight

This process is highly favorable for ATP under standard conditions

hydrolysis

The study of energy and its transformations

thermodynamics

Part of the universe we single out for study

system

A measure of randomness or disorder

entropy

Reactions are favorable when the free energy of products is much ___ than the free energy of reactants

lower

Which Law of Thermodynamics states that although energy can be transformed from one kind into another, it cannot be created or destroyed

First Law of Thermodynamics

For a spontaneous change, the change in Gibbs free energy is:

negative

Which Law of Thermodynamics states, any irreversible process results in an increase in entropy

Second Law of Thermodynamics

To transfer energy as heat, we make use of ____ motion of molecules

disorderly

System and surrounding cannot be restored to initial condition

irreversible

If the equilibrium constant (K) is greater than 1, the change in Gibbs free energy at standard state is ___ than zero

less

For an irreversible change, the change in entropy of the system is

positive

Actual free energy change depends on standard free ___ and ___ of reactants and products

energy, concentrations

A reaction that uses oxygen

oxidation

A system that can exchange both energy and matter with its surroundings

open

Unfavorable reactions can be made possible by chemically ____ favorable reaction to the unfavorable reaction

coupling

When Keq is greater than one, delta G is negative and the reaction proceeds

forward

Change in H is negative

exothermic

Standard free energy changes are

additive

Energy is the capacity to do ___ or transfer ___

work, heat

Define work

• movement of an object against some force

• force is a push/pull exerted on an object

Define heat

flow of energy from a body at a higher temp to one at a lower temp

Kinetic energy is the energy possessed due to its

motion

Potential energy is the energy due to its ___

position

Internal energy is the sum of

kinetic and potential energy

A system that can exchange energy but not matter with its surroundings

closed

A system that can exchange neither matter nor energy with its surroundings

isolated

Define A

an open system exchanging mass with its surroundings

Define B

a closed system exchanging work with its surroundings

Define C

A closed system exchanging heat with its surroundings

Define D

An isolated system in which neither work nor heat can be exchanged through boundaries

If w is done onto system:

w > 0

If w is done by system:

w < 0

If q is absorbed from from the surroundings:

• q > 0

• endothermic

If q is released to the surroundings:

• q < 0

• exothermic

When heat is added to a system or work is done on a system, its internal energy

increases

Change in enthalpy is positive

endothermic

NaOH dissolving in water is

• exothermic

  • heat is liberated

  • change in enthalpy is negative

NaNO3 dissolving in water is

• endothermic

  • heat is absorbed → solution becomes cooler

  • change in enthalpy is positive

To transfer energy as work, we make use of ___ motion of molecules

orderly

For a non-spontaneous change, the change in Gibbs free energy is

positive

The more negative the change in Gibbs free energy,

the larger the equilibrium constant

The larger the equilibrium constant,

the greater the equilibrium lies to the right (favors products)

If two systems are at the same time in thermal equilibrium with a third, then all three are in thermal equilibrium

Zeroth Law of Dynamics

Living organisms:

• cannot create energy from nothing

• cannot destroy energy into nothing

• may transform energy from one form to another

Breaking solute-solute attractions is

endothermic (+)

Breaking solvent-solvent attractions is

endothermic (+)

Forming solute-solvent attractions is

exothermic (-)

If the total energy released for solvation is greater than the total energy absorbed for dispersion, this reaction would be said to be

exothermic

The change in Gibbs free energy in transporting 0.1 mole of urea from the plasma to urine is approximately 259 calories. Is this process spontaneous or non-spontaneous?

non-spontaneous bc delta G is positive

When Keq is less than 1, delta G is positive and the reaction proceeds in

reverse

Under standard conditions, hydrolysis of ATP is typically non-spontaneous

false

• delta G is negative → spontaneous