Life Requires A Continual Energy Flux

Question 1

Life is not a thing, but a

Answer 1

Process powered by energy harvested from the environment

Question 2

The total entropy of a system and it’s surroundings

Answer 2

Increases for a spontaneous process

Question 3

Entropy

Answer 3

A measure of the disorder or randomness of a system

Question 4

What is the fate of the universe in line With the 2nd law

Answer 4

• heat death
• the big chill
• all matter has reached an equilibrium state of maximum disorder
• no spontaneous reactions
• no energy available

Question 5

Heat energy always flows from

Answer 5

Hot to cold

Question 6

Heat

Answer 6

The random motion of atoms or molecules in collision

Question 7

How do steam engines use the second law?

Answer 7

• heat generates water vapour
• vapour expansion coupled to mechanical work

Question 8

The second law dictates that

Answer 8

Processes proceed spontaneously until an equilibrium is reached

Question 9

What is statistical mechanics?

Answer 9

• predicts how atomic or molecular properties (mass, charge, position) determine physical properties of matter
• probability distributions of relationship between micro system states and macroscopic matter properties (eg temperature, viscosity)

Question 10

Who developed statistical mechanics?

Answer 10

• Ludwig Boltzmann
• James Clerk Maxwell
• Josiah Willard Gibbs

Question 11

Entropy equation

Answer 11

S = k.ln W
S = entropy
k = constant
W = number of possible micro states corresponding to the macro state of the system

Question 12

Why will a system almost always be found either in the state of maximum disorder or moving towards it?

Answer 12

There are so many more possible disordered states than owhat der d ones

Question 13

What is the second law, under the lens of statistical mechanics?

Answer 13

Statistical probability for matter made or mechanically colliding particles

Question 14

Life clearly involves

Answer 14

An increase in order (decrease in entropy)

Question 15

Local entropy can decrease spontaneously (matter becomes more ordered) as long as

Answer 15

The total entropy of the system as a whole increases

Question 16

Life is possible because

Answer 16

It’s biochemical processes increase the entropy of the environment

Question 17

Living organisms take up

Answer 17

• ordered forms of energy (low entropy) from the environment
• release them as less ordered forms (high entropy)

Question 18

Entropy within a cell

Answer 18

• is decreased (highly ordered macromolecules are formed)
• total energy of the system + surroundings increases

Question 19

Macromolecule formation does not occur

Answer 19

Spontaneously

Question 20

How is macromolecule formation achieved?

Answer 20

• expenditure of free energy by nucleotide triphosphate hydrolysis (eg ATP or GTP)

Question 21

Spontaneity equation

Answer 21

ΔSsystem + ΔSsurroundings = ΔSuniverse = +ve

Question 22

Gibbs free energy concept

Answer 22

ΔG is always negative for a spontaneous process

Question 23

ΔG equation

Answer 23

ΔG = ΔHsystem - TΔSsystem

Question 24

H

Answer 24

Enthalpy

Question 25

T

Answer 25

Temperature in Kelvin

Question 26

Enthalpy

Answer 26

Measure if change in heat in the system (reaction)

Question 27

For spontaneous reactions, ΔHsystem is

Answer 27

Negative

Question 28

Spontaneous reactions are

Answer 28

Exothermic

Question 29

What does exo/endothermy depend on

Answer 29

The chemical bond energies of the reactants and products

Question 30

Why do covalent bonds form?

Answer 30

They are more stable arrangements that separate atoms

Question 31

Breaking chemical bonds takes

Answer 31

Energy

Question 32

The more stable (strong) the bond

Answer 32

The more energy it takes to break it

Question 33

ΔHsystem

Answer 33

- net energy release - energy added to break reactant bonds - energy released from forming product bonds

Question 34

In exothermic reactions,

Answer 34

- more energy is released from forming the product bonds than is required to break the reactant bonds - ΔHsystem < 0

Question 35

A reaction can be made to occur spontaneously by

Answer 35

Coupling to a second, more favourable reaction

Question 36

Example of reaction coupling for spontaneity

Answer 36

Glucose + fructose -> sucrose + H2O (+27kJ/mol) ATP + H2O -> ADP + Pi (-30kJ/mol) Glucose + fructose + ATP -> sucrose + ADP + Pi (-3kJ/mol)

Question 37

The chemistry of life is kept away from equilibrium by

Answer 37

Expenditure of energy

Question 38

Stable, non-equilibrium systems

Answer 38

- When energy is poured into a system and the system dissipates, that energy slides towards increased entropy - on this slide, it can become poised in an orderly configuration

Question 39

Is ATP a universal energy currency

Answer 39

Yes

Question 40

What is a nucleoside?

Answer 40

Base + sugar (no phosphate)

Question 41

Energy can be captured as ATP by

Answer 41

- Catabolism of organic molecules coupled to ATP and NADH synthesis

Question 42

Heterotroph

Answer 42

Ah organism that depends on intake of organic environmental carbon sources

Question 43

Photoautotrophs

Answer 43

convert light energy to chemical energy using inorganic molecules such as H2O or H2S as electron donor

Question 44

How do autotrophs fix carbon into sugars

Answer 44

- extracted electrons generate ATP and reduced electron carriers (eg NADPH) - these drive biochemical cycles for atmospheric CO2 fixation

Question 45

Non-equilibrium systems are

Answer 45

An inevitable consequence of the second law in a system that is abundant in energy

Question 46

Evolution of photosynthesis allows

Answer 46

Translocation of life away from hydrothermal smokers

Question 47

Heat and CO2 escape causes

Answer 47

Tertiary energy loss