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Flashcards in Quiz 2 Deck (180):
1

Is heat flow a source of energy

no

2

What is Gibbs Free energy

stored energy that can be measured

3

What does Gibbs Free energy express

the amount of energy capable of doing work in a reaction

4

What are the requirements for standard transformed conditions

25C
1atm
1M of reactants and products
ph 7.0

5

What is the formula for pH calculation

ph=-log[H+]

6

Are there exceptions to 1 M concentrations for standards

yes

7

What are the exceptions to 1M concentrations for standards

H+
H2O
Mg2+

8

What is the standard concentration for H+

1.0x 10^-7

9

What is the standard concentration for H2O

55.5 M

10

What is the standard concentration for Mg2+

1 mM

11

What is equilibrium

when the rates of forward and reverse reactions are equal

12

At equalibrium are the concentrations of reactants and products equal

no

13

While the concentrations are not equal at equilibrium, what has occurred to the concentrations at equilibriu

they reach a steady state

14

Do organisms typically reach equilibrium, why or why not

no, because they would die due to no driving force

15

When the ratio is greater than one, does the reaction favor the reactants or products

products

16

If a reaction has a negative equilibrium constant, what does that indicate about the reaction

the reaction is exergonic, favorable under standard conditions

17

For two reactions, how can you calciulate the standard free energy change

add the two reactions together because standard free energy changes are additive

18

What is entropy

measure of randomness in an equation

19

What is enthalpy

measures bonding

20

Under favored conditions what is enthalpy

negative

21

Under favored conditions what is entropy

positive

22

under favored conditions what is free energy change

negative

23

Why is metabolism used by the cell

to obtain chemical energy
convert nutrient molecules into cell's molecules
polymerize monomeric precursors into macromolecules
synthesize and degrade biomolecules required for specialized cellular functions

24

How does the cell obtain chemical energy

by capturing solar energy or degrading energy rich nutrients from the environment

25

According to the chemical form in which they use carbon from the environment, what two groups can living organisms be divided into

autotrophs
hetertrophs

26

What are some autotrophs

photosynthetic bacteria, green algae, vascular plants

27

How do autotrophs obtain carbon

uses CO2 from atmosphere as their sole source of carbon

28

How do hetertrophs obtain carbon

complex organic molecules

29

Can heterotrophs obtain carbon through CO2

no

30

What are some heterotrophs

multicellular animals and most organisms

31

What are heterotrophs dependent upon

products of other organism

32

What are autotrophs dependent upon

nothing, they are self sufficient

33

Do all organisms need nitrogen

yes

34

How do bacteria obtain nitrogen

ammonia or nitrates

35

How do vertebrates obtain nitrogen

in forms of amino acids or other organic compounds

36

How does energy flow through the biosphere

one way

37

Why does energy only flow through the biosphere in one way

organisms cannot regenerate useful energy from energy dissipated as heat and energy

38

Can carbon oxygen and nitrogen recycle continuously

yes

39

Why can't the energy from these compounds be regenerated

energy is transferred into unusable forms such as heat

40

What is metabolism

sum of all chemical transformations taking place in a cellular organism

41

What allows these chemical transformations to take place

series of enzyme catalyzed reactions

42

What are these enzyme catalyzed reactions called

metabolic pathways

43

What does each step in the pathways cause

a removal, transfer, addition of an atom or functional group

44

What is a metabolite

metabolic intermediates

45

How does metabolite interact in the metabolic pathway

precursor is converted into a product through a series of metabolites

46

What is intermediatory metabolism

the combined activities of all metabolic pathways that interconvert precursors, metabolites and products

47

What is catabolism

degradative phase of metabolism

48

What occurs during catabolism

molecules are converted into smaller and simpler end products

49

What energy change occurs during catabolism

energy is released

50

In what types of forms is energy released

ATP and reduced electron carriers

51

What is anabolism

building phase of metabolism

52

What occurs during anabolism

biosynthesis, small simple precursors are built up into larger and more complex molecules

53

What types of molecules are built during anabolism

lipids, polysaccharides, proteins, nucleic acids

54

What energy change occurs during anabolism

required energy input

55

How is energy input into anabolism

phosphoryl group exchange and reducing power of NADH, NADPH, FADH2

56

What is a cyclic pathway

one starting component of the pathway is regenerated in a series of reactions that convert another starting component into a product

57

Can organisms do both anabolism and catabolism

yes

58

What occurs in organisms when anabolism is occurring

catabolism is suppressed (vice versa)

59

Because one pathway is suppressed, what must occur in order to not shut down both pathways

there must be different enzymes for both reactions/ pathways

60

What are the two ways that metabolic pathways are regulated

availability of the substrate
allosteric regulation by a metabolic intermediate or coenzyme

61

When does the availability of the substrate have an impact on metabolic pathways

when near or below Km

62

What types of metabolic intermediates of conenzymes regulate metabolic pathways

amino acids, ATP, growth factors, hormones

63

What does bioenergetics study

energy transductions

64

What are energy transductions

changes of one form of energy into another

65

Where do energy transductions occur

in living cells, nature

66

What is the 1st law of bioenergetics

the total amount of energy in the universe remains constant, energy may change form or be transported from one region to another, but it cannot be created or destroyed

67

What is the 2nd law of bioenergetis

all natural process, the entropy of the universe increases

68

What is Gibbs free energy

amount of energy capable to do work during a reaction at constant temperature and pressure

69

a negative gibbs free energy is what

exergonic

70

a positive gibbs free energy is what

endergonic

71

What does enthalpy measure

heat content of the reacting system

72

What does enthalpy reflect

number and kins of chemical bonds

73

If a reaction released heat what is it

exothermic

74

If a reaction absorbs heat from its surrounding what is it

endothermic

75

What does entropy measure

the randomness or disorder in a system

76

A gain in entropy indicates what

more disorder

77

WHy is heat flow not a source of energy

heat can only do work as it passes to a zone or object at a lower temperature

78

Where does photosynthetic organisms get energy

solar radiation

79

Where do heterotropic get energy

nutrient molecules

80

What are solar radiation and nutrient molecules converted into

ATP

81

How is the standard transformed constants identified

written with prime '

82

If Keq' is greater than one, what is it's standard free energy change

negative

83

If Keq' is less than one, what is its standard free energy change

positive

84

When the standard free energy change is negative is the reaction spontaneous forward or backward

forward

85

Why is a negative free energy change spontaneous forward

products contain less free energy than the reactants

86

When standard free energy change is positive will the reaction be spontaneous forward or backward

backward reaction

87

WHy is a positive free energy change spontaneous backward

products contain more free energy than the reactants

88

What is the criteria for a system to be at equilibrium

rate of rxn forward is same going backward, no net change

89

Does the actual concentration of metabolites affect standard free energy change. WHy or why not

no, because when you calculate, you assume everything is 1M

90

Does the actual concentration of metabolites affect free energy change Why or why not

yes, you use this when testing under cellular or conditions other than standard

91

Metabolically irreversible reactions are what

reactions far from equilibrium

92

A reaction at equilibrium will have a delta G value of what

0

93

What is irreversible reaction in regards to free energy sign and magnitude, reactant/product concentrations

there is going to be a great amount of products in comparison to reactants, the free energy change value is going to be large and negative.

94

Which types of reactions are near equilibrium

reactions that only have a small energy change

95

Which type of reactions are far from equilibrium

reactions that have a large energy change

96

What is the energy that links catabolism and anabolism

ATP

97

Where do heterotropic cells obtain energy

catabolism of nutrient molecules

98

What do heterotropic cells use energy for

making ATP

99

What is ATP made from

ADP and P

100

What does ATP donate its chemical energy to?

endergonic processes

101

What are examples of endergonic processes

synthesis of metabolic intermediates and macromolecules from smaller precursors
transfer of substrates against its gradient
mechanical motion

102

What is the magnitude and sign for the free energy charge for ATP hydrolysis

Large and Negative

103

What does hydrolysis of ATP compose of

hydrolytic cleavage of the terminal phosphoric acid anhydride bond in ATP

104

What does cleaving the terminal phosphoric acid anhydride bond do

seperates one of the three negative charged phosphates

105

In cleaving one of the phosphates what is relieved

the electrostatic repulsion in ATP

106

How and Why is Pi stabilized

formation of several resonance structures

107

What is the standard free energy for ATP hydrolysis

-30.5kJ/mol

108

not under standard free energy changes what is the delta G

very different

109

Why is delta G different in actual conditions than the standard

cellular concentrations of ATP, ADP, Pi are not identical and much lower than 1.0M
Mg2+ binds to ATP and ADP which makes MgATP substrate

110

What is deltaGp

phosphorylation potential

111

What is phosphorylation potential

actual free energy of hydrolysis of ATP under intracellular conditions

112

Why can deltaGp differ between the cells

depends upon metabolic conditions and how ATP, ADP, Pi concentrations are altered

113

What is the free ADP in resting muscles estimated to be between

1 and 37 uM

114

Where should ATP concentrations be held in regards to equilibrium

far above for the hydrolysis reaction

115

When ATP levels drop, what occurs

amount of fuel decreases and the fuel loses potency

116

What are some other phosphorylated compounds

PEP
1,3 bisphosphoglycerate

117

What is PEP stand for

phosphoenolpyruvate

118

What does PEP contain structure wise

a phosphate ester bond

119

What does the phosphate ester bond undergo

hydrolysis

120

What does the phosphate ester bond undergoing hydrolysis yield

the enol form of pyruvate

121

What occurs to the enol form of pyruvate

it tautermerizes to the more stable keto form

122

What is the standard free energy of hydrolysis of PEP

-61.9 kJ/mol

123

What structure wise does the 1,3 bisphosphoglycerate molecule contain

anhydride bond

124

hydrolysis of 1,3 bisphosphoglycerate has what standard free energy change

-49.3 kJ/mol

125

When water is added across the anhydride bond of 1,3 bisphosphoglycerate, what is one of the direct products

3- phosphoglyverate

126

How many resonance forms does 3-phosphoglycerate have

two

127

In phosphocreatine, the P-N bond can be hydrolyzed to produce what

creatine and Pi

128

What is the delta G for phosphocreatine to creatin

-43.0 kJ/mol

129

What is a thioester

sulfur atom replaces the usual oxygen in the ester bond

130

What type of standard free energy changes occur for hydrolysis of thioesters

large, negative

131

How do thioesters compare to esters in regards to resonance

thioesters have less resonance stabilization

132

What does hydrolysis of esters produce

a carboxylic acid

133

What is the standard free energy for hydrolysis of esters

-31.4 kJ/mol

134

How do the produces vs reactants compare for reactions with a large neg. delta G

products are more stable than reactants

135

What is bond strain in reactants due to

electrostatic repulsion

136

How is electrostatic repulsion relieved

charge separation

137

How are the products of a reaction stabilized

ionization, isomerizations, resonance

138

ATP hydrolysis only accomplishes what

heat liberation

139

Can heat liberation drive a chemical process in an isothermal system

no

140

What is the first step of phosphate transfer

phosphoryl group is transferred to a substrate molecule or to an amino acid

141

How is the phosphate attached to the substrate molecule

covalently attached

142

How does covalently being attached affect free energy content

raises its free energy content

143

What is the second step of phosphate transfer

The phosphate is displaced generating, Pi, Pd or AMP

144

How does ATP participate to which it contributes free energy

covalently in the enzyme catalyzed reaction

145

How much energy can hydrolysis of ATP provide in regards to how much work can occur

enough to cycle proteins between two conformations

146

Cycling proteins between two conformations produces what

mechanical motion

147

What are the two groups phosphate compounds are divided into

high and low energy

148

What rule says a compound is high energy

the delta G is more negative than -25kJ/mol

149

What rule says a compound is low energy

the delta G is greater than -25kJ/mol

150

Why is breaking a bond and getting energy misleading

the bond does not contain energy

151

Breaking a bond is always what

endothermic

152

Where does the free energy result when breaking ATP bond

products of the reaction that have a lower free energy than the reactants

153

Reactions of ATP are what type of reactions

SN2 nucleophilic displacements

154

Each of the 3 phosphates are subject to what

nucleophilic attack

155

What is adenylation

attack at the alpha position, displaces PP and transfers adenylate as an adenyly group

156

What is adenylate

5'AMP

157

PP is hydrolyzed by what enzyme

pyrophosphatase

158

How much energy is released through pyrophosphatase

19 kJ/mol

159

What reactions fuel all work done in orgnaisms

redox

160

What is a reduced source of electrons

food

161

How do electrons move

via complex pathways

162

What do cells do to electrons

convert electrons into work

163

What does LEO says GER stand for

loss electrons oxidation
gain electrons reduction

164

What is emf

electromotive force

165

Is electron affinity similar for all chemical species

no

166

When electrons flow through a circuit what do they produce

emf

167

When charge increases is this oxidation or reduction

oxidation

168

When charge decreases is this oxidation of reduction

reduction

169

is glucose oxidized or reduced

oxidized

170

electrons flow from what position to what position

lower to higher potentials

171

What does reduction potential depend upon

the specific activities

172

How does delta E relate to delta G

electron flow results in energy

173

What is the benchmark standard reduction potential reaction

H+ + e- to 1/2 H2

174

What is the reduction potential for the benchmark reaction

E=0V

175

true or false
breaking any bond is always exothermic

false

176

True or False
breaking any bond is always endothermic

true

177

Why is breaking any bond always endothermic

because bonds are stable

178

True or False
whether breaking a bond is endothermic or exothermic depends on the bond

False

179

True or False
Any reaction that involves ATP as a reactant will have a large negative deltaG

False

180

Why won't all reactions involving ATP have a large negative deltaG

if the products are more positive than reactants, this would lead to a positive deltaG