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Flashcards in Thermodynamics Deck (59):
1

What is the first law of thermodynamics

Conservation of energy: Energy remains constant; it may change from one form to another but it cant be created or destroyed.

2

What is the second law of thermodynamics

In all natural processes, the entropy of the universe increases. Total entropy includes both the system and surroundings

3

Living organisms are ____systems

open

4

We can ___order within ourselves but ____order in our surroundings.

create; decrease

5

We extract energy from nutrients via _____reactions

catabolic

6

We use energy for work:

motion, ionic/electrical gradients, anabolic reactions,

7

____processes produce simple components and increase entropy

Catabolic

8

____processes use simple components and decrease entropy

Anabolic

9

Gibbs free energy is defined in terms of:

1. Enthalpy: a measure of heat energy that reflects bond formation and breakage
2. Entropy (S): randomness
3. Temperature (T): in K

10

If delta H is greater than 0=

endothermic; heat energy is absorbed

11

If delta H is less than 0

exothermic; heat energy is released

12

By convention delta S is positive when

entropy increases

13

By convention delta H is negative when

heat is released to the surroundings

14

By convention T is always

positive

15

Endergonic reactions require ____ of energy (positive delta G); and its thermodynamically _____

input; unfavorable

16

Exergonic reactions ____energy (negative delta G); and its thermodynamically ____ and _____

release; favorable and spontaneous

17

Endergonic reactions can be coupled to ____reactions to drive a thermodynamically unfavorable process forward, often by coupling to the hydrolysis of ____

exergonic; ATP

18

Equilibrium is formation of products = formation of _____

reactants

19

Delta G of chemical reactions is alternative of equilibrium contant:

Keq

20

Equilibrium constant is constant as ratio of products over

reactants

21

If Keq is greater than 1, then:

products is greater than reactants and the reaction goes forward

22

If Keq is less than 1 then:

Products is less than reactants and the reaction goes in reverse

23

If Keq is = 1 then:

products is equal to reactants. There is no reaction

24

Delta G is actual energy used for ___

analysis

25

Delta G with degrees is ____condition

standard; used for general comparison

26

Delta G with degrees and prime is used for ______standard conditions

biological

27

Delta G degrees and prime is equal to

-RTln Keq

28

Reaction rate depends on ____ energy

activation

29

If delta G prime and degrees is greater than 23 kj/mol or Keq is less than 10^-4 the reaction is biologically

irreversible

30

Overall free energy change is :

additive

31

Overall equilibrium constant is :

multiplicative

32

RT =

2.478 kJ/mole

33

Delta G prime and degrees is equal to

-RTlnKeq

34

If we remove product as it is formed, then product will be low and overall delta G can be be ____even if Delta G prime with degrees is greater than 0

negative

35

When Keq is greater than 1:

Delta G prime +degrees is negative and the reaction proceeds forward

36

When Keq is 1:

Delta G prime +degrees is 0 and the reaction is at equilibrium

37

When Keq is less than 1

Delta G prime + degrees is positive and the reaction proceeds in reverse

38

How much ATP is in the body?

100g

39

How much ATP does a resting human consume per day

40 kg

40

How fast is ATP typically consumed

Usually within 1 minute of formation

41

How does ATP store energy

1. charge repulsion relieved when hydrolized
2. resonance stabilization of Pi
3. Ionization of ADP
4. Stabilization of ADP by Mg2+ chelation
5. Maintain low ATP concentration

42

What is PEP

member of glycolytic pathway used by bacteria as energy source to conserve ATP

43

Catabolic processes are ____ and _____

exergonic (produce energy) and oxidative (produce NADH/NADPH)

44

Anabolic processes are _____ and _____

endergonic (require energy) and reductive ( use NADH/NADPH)

45

Oxidation is ____of electrons

loss

46

Reduction is ____of electrons

gain

47

Redox reactions are driven by

electron transfer

48

Electrons are transferred by 4 methods:

1. directly as electrons
2. as H atoms
3. as a hydride ion
4. direct combination with oxygen

49

___ _____ is commonly used to designate a single electron equivalent participating in an oxidation-reduction reaction regardless of which of the four is the electron source.

Reducing equivalent

50

What is nitric oxide (NO)

A gaseous hormone

51

Biological redox largely based on the aa:

cysteine

52

Redox reactions happen in pairs called:

Redox couple

53

Enzymes that catalyze these reactions are called

dehydrogenases

54

Electron accepting molecule is the ____agent has and a ____E delta prime

oxidizing; positive

55

Electron donating molecule is the ____agent and has a ____E delta prime

reducing; negative

56

In a redox couple, the molecule with the more _____E delta prime will accept electrons and get _____; it has the greater ____ _____

positive; reduced; reduction potential

57

A more positive delta E prime gives you a more ___delta G prime

negative

58

What are some characteristics of NADH and NADPH

1. Freely soluble (not protein bound)
2. Transfers 2 electrons, 1 proton
3. Has a fixed E delta prime

59

In riboflavin aka Vitamin B2:

Dela E prime is not fixed