1. Thermodynamics

Question 1

What is the conservation of energy?

Answer 1

energy cannot be created or destroyed

Question 2

How does entropy work within the laws of thermodynamics?

Answer 2

the disorder of a system always increases

Question 3

How do living organisms follow the conservation of energy?

Answer 3

they transform energy from one form to another

Question 4

How do organisms use energy from their environment?

Answer 4

extract useable energy from surroundings and release useless energy back in the form of heat

Question 5

What happens to the entropy of the universe while transforming energy?

Answer 5

it increases

Question 6

Define transductions

Answer 6

one thing to another

Question 7

What state do living organisms exist in?

Answer 7

dynamic steady state

Question 8

What allows living organisms to transform matter into energy and what do they use?

Answer 8

energy coupling and catalysts

Question 9

Are living organisms ever at equilibrium with their surroundings?

Answer 9

no

Question 10

When entropy increases, what is needed to create and maintain order?

Answer 10

work and energy

Question 11

Define an open system

Answer 11

exchange both energy and matter with surroundings

Question 12

What type of system are humans?

Answer 12

open system

Question 13

Define closed system

Answer 13

exchange only energy with surroundings

Question 14

Define isolated system

Answer 14

cannot exchange energy or matter with surroundings

Question 15

What is the ultimate source of energy on earth?

Answer 15

sunlight

Question 16

Define metabolism

Answer 16

sum of all chemical reactions in the cell

Question 17

Define anabolism

Answer 17

making complex molecules from simpler ones

Question 18

Does anabolism require or release energy?

Answer 18

require

Question 19

Define catabolism

Answer 19

breaking down complex molecules into simpler ones

Question 20

Does catabolism require or release energy?

Answer 20

release

Question 21

What three quantities define the free energy content of any closed system?

Answer 21

entropy, enthalpy and absolute temperature

Question 22

Define entropy

Answer 22

randomness or disorder of a system

Question 23

When disorder increases, how does this affect entropy?

Answer 23

it becomes positive

Question 24

When disorder decreases, how does this affect entropy?

Answer 24

it becomes negative

Question 25

Define enthalpy

Answer 25

sum of a system's internal energy, or heat

Question 26

When enthalpy (H) is positive, is the equation endothermic or exothermic?

Answer 26

endothermic

Question 27

When enthalpy (H) is negative, is the equation endothermic or exothermic?

Answer 27

exothermic

Question 28

Define endothermic

Answer 28

absorb heat energy from surroundings

Question 29

Define exothermic

Answer 29

release thermal energy to surroundings

Question 30

What two factors, at a constant temperature, affect the free energy change?

Answer 30

change in enthalpy and entropy

Question 31

What is the standard free energy change and what symbol is it?

Answer 31

Delta G - constant characteristic for a specific reaction at standard conditions

Question 32

What are the standard conditions for the free energy change?

Answer 32

temp - 25 C pressure - 1 atm reactants - 1M

Question 33

When delta G^'o is negative, is the reactions exergonic or endergonic?

Answer 33

exergonic

Question 34

Define exergonic reaction

Answer 34

reaction can occur spontaneously releases free energy

Question 35

When Delta G^'o is positive, is the reaction exergonic or endergonic?

Answer 35

endergonic

Question 36

Define an endergonic reaction

Answer 36

the reaction doesn't occur spontaneously requires energy

Question 37

What do thermodynamic constants, such as delta G^'o show?

Answer 37

where the final equilibrium lies

Question 38

How do cells carry out endergonic reactions?

Answer 38

coupled to exergonic reactions

Question 39

When Delta G^'o is negative, what is Keq

Answer 39

>1

Question 40

When Delta G^'o is positive, what is Keq?

Answer 40

<1

Question 41

When Keq is >1, which way does the reaction proceed?

Answer 41

forward

Question 42

When Keq is <1, which way does the reaction proceed?

Answer 42

reverse

Question 43

Define energy coupling

Answer 43

chemical coupling of exergonic and endergonic reactions allowing otherwise unfavorable reactions to occur

Question 44

What does the actual free energy change of a reaction in the cell depend on?

Answer 44

standard change in free energy and actual concentrations of products and reactants

Question 45

What is the best way to speed up a reaction?

Answer 45

lowering the activation barrier by using catalysts

Question 46

What do enzymes (catalysts) do?

Answer 46

lower activation energy and raise reaction rate

Question 47

Define a biochemical pathway

Answer 47

series of related enzyme-catalyzed reactions

Question 48

Do catalysts alter Delta G?

Answer 48

no

Question 49

How do catalysts affect the activation free energy?

Answer 49

lower it

Question 50

Why are pathways controlled?

Answer 50

regulate levels of metabolites