[BIOENERGETICS AND ATP SYNTHESIS IN PROKARYOTES] -- MICROPHYSIO FINALS

Bioenergetics

__________ is the study of energy transformations in living organisms.

free energy, entropy

The two principal thermodynamic concepts in bioenergetics are __________ and __________.

chemical equilibria

Free energy and its relationship with __________ illustrates how displacement of a reaction from equilibrium can be used to drive vital reactions.

maintenance, replication

Energy is an absolute requirement for the __________ and __________ of life regardless of its form.

environment

All around us we see biological organisms extracting materials from their __________ and using them to maintain their organization or to build new, complex structures.

order

Energy to build and preserve __________ in the face of a constantly deteriorating environment is a fundamental need of all organisms.

photosynthesis, respiration

Two main strategies have evolved to acquire energy: __________ and __________.

Photosynthesis

photoautotrophic

__________ is characteristic of a __________ lifestyle, which traps energy from the sun to build complex structures out of simple inorganic substances.

Respiration

chemoheterotrophic

__________ characterizes the __________ lifestyle, which require a constant intake of organic substances from their environment, from which they can extract their necessary energy through respiration.

sun

Most life on Earth is ultimately powered by energy from the __________.

Electrochemical

__________ energy refers to ion gradients across membranes that energize transport and other processes.

Electrochemical energy

__________ energizes solute transport, flagella rotation, ATP synthesis, and membrane activities.

Chemical

ATP, PEP

__________ energy includes high-energy molecules in the soluble part of the cell like __________ and __________.

ATP,

BPGA,

PEP,

acetyl-P,

acetyl-CoA,

succinyl-CoA

Examples of high-energy molecules include:

Oxidation-reduction

__________ reactions are key to biological energy transformations, involving electron transfers.

chemiosmotic

adenosine triphosphate (ATP)

The __________ model for synthesis of __________ explains how ATP is synthesized through proton gradients across membranes.

thermodynamic laws

Bioenergetics is the application of __________ __________ to the study of energy transformations in biological systems.

mechanical work

chemical syntheses

solute; electrochemical gradients

osmosis

ecosystem

The biologist is concerned with __________, __________, the movement of __________ against __________, __________, and __________ dynamics.

equilibrium

oxidation-reduction

The energetics of cellular processes can be related to chemical __________ and __________ potentials of chemical reactions.

energy

Whether at the level of molecules, cells, or ecosystems, the flow of __________ is central to the maintenance of life.

Bioenergetics

the field of study concerned with the flow of energy through living organisms

photosynthesis, respiration

A central focus of bioenergetics has been to unravel the complexities of energy transformations in __________ and __________.

ATP, ions

Understanding how energy is used to drive energy-requiring reactions such as __________ synthesis and accumulation of __________ across membranes.

conservation

First Law of Thermodynamics

The first law of thermodynamics is also called the law of __________ of energy.

constant

First Law of Thermodynamics

The energy of the universe is __________.

fixed

moved about

changed in form

First Law of Thermodynamics

There is a __________ amount of energy and, while it may be __________ or __________, it can all be accounted for somewhere.

created, destroyed

form

First Law of Thermodynamics

Energy cannot be __________ or __________, but it can change __________.

increase

First Law of Thermodynamics

An apparent energy loss in one form is balanced by an __________ in another form

lost

increase

First Law of Thermodynamics

Energy is never "__________" in a reaction - an apparent decrease in one form of energy will be balanced by an __________ in some other form of energy.

entropy

Second Law of Thermodynamics

The second law of thermodynamics concerns __________, a measure of randomness, disorder, chaos.

Temperature

Second Law of Thermodynamics

__________ is defined as the mean molecular kinetic energy of matter

thermal energy

Second Law of Thermodynamics

Any molecular system not at absolute zero contains a certain amount of __________ energy.

vibration

rotation

translation

Second Law of Thermodynamics

Thermal energy includes __________, __________, and __________ of molecules.

temperature

Second Law of Thermodynamics

As the quantity of energy increases or decreases, so does __________.

Isothermally

entropy

molecular motion

Second Law of Thermodynamics

__________ unavailable energy, and consequently __________, are related to the energy of __________

random

Second Law of Thermodynamics

The more molecules are free to move, the more __________ or less ordered the system.

R. J. Clausius

Second Law of Thermodynamics

__________: the entropy of the universe tends toward a maximum.

work

Second Law of Thermodynamics

Entropy represents energy that is not available to do __________.

isolated

decreases

Second Law of Thermodynamics

The second law can be re-stated as: the capacity of an __________ system to do work continually __________.

work

Second Law of Thermodynamics

It is never possible to utilize all of the energy of a system to do __________.

higher

nutrients

wastes; heat

Cell Order and Entropy Export

Cells maintain a relatively __________ degree of order compared with their environment by continually importing free energy in the form of __________ and exporting entropy as disordered __________ and __________.

nutrients

cell membrane

order

Cell Order and Entropy Export

Cells selectively import ordered __________ from a largely chaotic world via its semipermeable __________.

This ensures the cells maintain higher internal __________ compared with their external environment.

isothermal

Gibbs free energy

Free Energy Basics:

Some energy will be available under __________ conditions and is available to do work.

This energy is called __________ in honor of J.W. Gibbs.

Free energy

Entropy

Free Energy Basics:

There are two kinds of energy:

__________ - available to do work

__________ - not available to do work.

minimum

Free Energy Basics:

The free energy of the universe tends toward a __________.

free energy

Free Energy and Reaction Feasibility

Changes in __________ can tell us much about a reaction.

∆G

Free Energy and Reaction Feasibility

Feasibility of a reaction is indicated by the sign of __________.

spontaneous

Free Energy and Reaction Feasibility

If the sign is negative (i.e., ∆G < 0), the reaction is considered __________, meaning it will proceed without an input of energy.

exergonic

Free Energy and Reaction Feasibility

Reactions with a negative ∆G are sometimes known as __________, or energy yielding.

energy

Free Energy and Reaction Feasibility

If ∆G is positive, an input of __________ is required for the reaction to occur.

endergonic

Free Energy and Reaction Feasibility

Reactions with a positive ∆G are known as __________, or energy consuming..

free energy

uniform

Free Energy Change (∆G)

A living system's __________ is energy that can do work when temperature and pressure are __________, as in a living cell.

change in enthalpy

change in entropy

temperature

Free Energy Change (∆G)

The change in free energy (∆G) during a process is related to the change in __________ (∆H), change in entropy (∆S), and __________ in Kelvin (T).

T∆S

Free Energy Change (∆G)

∆G = ∆H - __________

negative

Free Energy Change (∆G)

Only processes with a __________ ∆G are spontaneous

work

Free Energy Change (∆G)

Spontaneous processes can be harnessed to perform __________.

Free energy

Stability and Equilibrium

__________ is a measure of a system's instability, its tendency to change to a more stable state.

decreases

Stability and Equilibrium

During a spontaneous change, free energy __________ and the stability of a system increases.

Equilibrium

Stability and Equilibrium

__________ is a state of maximum stability.

equilibrium

Stability and Equilibrium

A process is spontaneous and can perform work only when it is moving toward __________.

exergonic

Exergonic and Endergonic Reactions

An __________ reaction proceeds with a net release of free energy and is spontaneous.

endergonic

Exergonic and Endergonic Reactions

An __________ reaction absorbs free energy from its surroundings and is nonspontaneous.

released

spontaneous (∆G < 0)

Exergonic and Endergonic Reactions

In an exergonic reaction, energy is __________ and it is __________.

required

nonspontaneous (∆G > 0)

Exergonic and Endergonic Reactions

In an endergonic reaction, energy is __________ and it is __________.

equilibrium

Equilibrium and Metabolism

Reactions in a closed system eventually reach __________ and then do no work.

open

Equilibrium and Metabolism

Cells are not in equilibrium; they are __________ systems experiencing a constant flow of materials.

metabolism

Equilibrium and Metabolism

A defining feature of life is that __________ is never at equilibrium.

catabolic

Equilibrium and Metabolism

A __________ pathway in a cell releases free energy in a series of reaction

exergonic, endergonic

ATP and Energy Coupling

ATP powers cellular work by coupling __________ reactions to __________ reactions.

chemical, transport, and mechanical

ATP and Energy Coupling

A cell does three main kinds of work:

energy coupling

ATP and Energy Coupling

Cells manage energy resources by __________, the use of an exergonic process to drive an endergonic one.

ATP

ATP and Energy Coupling

Most energy coupling in cells is mediated by __________.

ATP (adenosine triphosphate)

Structure and Hydrolysis of ATP

__________ is the cell's energy shuttle.

ribose

adenine

phosphate

Structure and Hydrolysis of ATP

ATP is composed of __________ (a sugar), __________ (a nitrogenous base), and three __________ groups.

hydrolysis

squiggle

Structure and Hydrolysis of ATP

ATP has bonds that have a high free energy of __________.

These bonds are sometimes depicted by a "__________" (~), and are called "high-energy" bonds.

group transfer

Structure and Hydrolysis of ATP

ATP has high __________ potential.

ionized

Phosphoryl Group Transfer

The phosphate group is shown as __________.

double-bond

semipolar

Phosphoryl Group Transfer

Because phosphorus is a poor __________ former, the phosphorus-oxygen bond exists as a __________ bond.

electronegative

Phosphoryl Group Transfer

The positively charged phosphorus is attacked by the __________ oxygen in the hydroxyl.

YOH

Phosphoryl Group Transfer

The leaving group is __________.

hydrolysis

inorganic phosphate

YOH

Phosphoryl Group Transfer

If ROH is water, then the reaction is a __________ and the product is __________ and __________.

free energies

Group Transfer Potential and Free Energy

One can compare the tendency of different molecules to donate phosphoryl groups by comparing the __________ released when the acceptor is water

negative

Group Transfer Potential and Free Energy

The group transfer potential is the __________ of the free energy of hydrolysis.

group transfer potential

Group Transfer Potential and Free Energy

The __________ is thus defined as the negative of the standard free energy of hydrolysis at pH 7.

group transfer potential

nucleophile

Group Transfer Potential and Free Energy

The __________ is a quantitative assessment of the tendency of a molecule to donate the chemical group to a __________.

−21 kJ/mol

ATP Coupling Reaction

ATP + glucose → glucose-6-phosphate + ADP ΔG′₀ = __________

−35 kJ/mol

ATP Coupling Reaction

ATP + H₂O → ADP + Pᵢ ΔG′₀ = __________

+14 kJ/mol

ATP Coupling Reaction

ATP + H₂O → ADP + Pᵢ ΔG′₀ = __________

coupled

ATP Coupling Reaction

The overall reaction ATP + glucose → glucose-6-phosphate + ADP is an example of a __________ reaction.

ATP hydrolysis

glucose phosphorylation

negative

ATP Coupling Reaction

Coupling an exergonic reaction (__________) with an endergonic reaction (__________) makes the overall ΔG′₀ __________.

glucose-6-phosphate

ATP Coupling Reaction

In the ATP + glucose reaction, the energy released from ATP hydrolysis is used to drive the formation of __________.

−35 kJ/mol

ATP Coupling Reaction

The standard free energy change for the hydrolysis of ATP is __________.

+14 kJ/mol

ATP Coupling Reaction

The standard free energy change for the phosphorylation of glucose is __________.

adding

ATP Coupling Reaction

The ΔG′₀ of the coupled reaction is calculated by __________ the ΔG′₀ values of the individual reactions.

spontaneous

ATP Coupling Reaction

A negative ΔG′₀ indicates a reaction is __________ under standard conditions.

hydrolysis

How the Hydrolysis of ATP Performs Work

The three types of cellular work (mechanical, transport, and chemical) are powered by the __________ of ATP.

exergonic

How the Hydrolysis of ATP Performs Work

In the cell, the energy from the __________ reaction of ATP hydrolysis can be used to drive an endergonic reaction.

exergonic

How the Hydrolysis of ATP Performs Work

Overall, the coupled reactions are __________.

phosphorylation

How the Hydrolysis of ATP Performs Work

ATP drives endergonic reactions by __________, transferring a phosphate group to some other molecule, such as a reactant.

phosphorylated intermediate

How the Hydrolysis of ATP Performs Work

The recipient molecule is now called a __________.