Chapter 3 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

GLycolysis generates

A

It generates a NET 2 ATP and 2 NADH, and 2 pyruvate molecules that can enter the citric acid cycle for more ATP synthesis

Please note that glycolysis DOES MAKE 4 ATPs total however it had to use up 2 to prepare the 6 carbon ring for cleavage (gotta spend some to make some)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

bond between the phosphate in ATP are ________: their hydrolysis is accompanied by a large decrease in free energy

A

high energy bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

for ATP hydrolysis delta G is how much (kcal/mol)?

A

-12kcal/mol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Alternatively, ATP can be hydrolyzed to AMP plus

A

pyrophosphate (PPi)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the pyrophosphate is then rapidly hydrolyzed, and the total free- energy change is about ____ that from hydrolysis of ATP to ADP

A

twice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

ATP hydrolysis can drive other reactions? True or false?

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The first step in glycolysis is ______ (delta G =3.3 kcal/mol)

but it is coupled to ATP hydrolysis (delta G = -7.3 kcal/mol) making delta G (-4 kcal/mol)

A

unfavorable

remember that the first step in glycolysis is unfavorable. This is why you have to spend 2 ATPs in the begging to make 4 ATPs (aka net gain of 2 ATPs)…. however it can be coupled with ATP hydrolysis and this is what makes the reactions still able to occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Glycolysis reaction equation: complete it:

glucose+ATP —.>

A

glucose-6-phospate+ADP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

energy yielding reactions within the cell are coupled to ____

A

ATP synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

energy-requiring reactions are coupled to ___

A

ATP hydrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

the complete oxidation breakdown of glucose to CO2 and H2O yields a large amount of energy:

A

delta G = -686 kcal/mol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

complete the reaction for the oxidative breakdown of glucose:

C6H12O6 +O2 —>

A

6CO2+6H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

to harness the free energy, glucose is oxidize in a series of steps coupled to

A

ATP synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The first step of generating ATP is __________ please describe it

A

glycolysis

occurs in all cells in the absence of oxygen; it can provide all the metabolic energy of anaerobic organisms

glycolysis results in the breakdown of glucose into pyruvate, with a net gain of 2 ATP

The first part of the pathway consumes energy

the enzymes that catalyze these reactions are important regulatory points; when there is an adequate supply of ATP, glycolysis is inhibited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

glycolysis also converts two molecules of the coenzyes

A

NAD+ to NADH…

NAD+ acts as an oxidzing agent that accepts electrons

NADH must be recycled by serving as an electron donor for other oxidation-reduction reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

in ___ the NADH is reoxidized to NAD+ by the conversion of pyruvate to lactate or ethanol

A

anaerobic conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

in ________ the NADH donates electrons to the electron transport chain

A

aerobic condtions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

glycolysis takes place in the

A

cytosol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

in eukaryotic cells, pyruvate is then transported in to __________ where it is completely oxidized

A

mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

pyruvate undergoes oxidative decarboxylation in the presence of _______________ forming____ generation of ______

A

in the presence of COENZYME A (COA-SH) forming ACETYL COA generation of 2NADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

______ enters the citric acid cycle

A

Acetyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

in the citric acid cycle the 2 carbon acetyl group

A

combines with oxaloacetate (4 carbons) to yield nitrate (6 carbons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

in the citric acid cycle the remaining involve the 2 carbons of citrate

A

being completely oxidized to CO2 , where oxaloacetate is regenerated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

2 carbons of citrate makes ??

A
2 CO2
1 oxaloacetate
1 GTP
3 NADH 
1 FADH2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The complete oxidation of glucose makes what?

A

6 Co2
4 ATP
10 NADH
2 FADH2

Note that makes a total of 38 ATPs because :

one FADH2 makes 2 ATPs

one NADH makes 3 ATPS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Give the total ATP yield of glycolysis

A

2 ATP+2NADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Give total ATP yield for citric acid cycle

A

2ATP, 8 NADH, 2 FADH2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

give total ATP yield for oxidative phophorylation

A

each NADH yields 3 ATP, each FADH2 yields 2 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

polysaccharides can be broken down to ___ which are metabolized by glycolysis and the Krebs cycle

A

sugars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

oxidation of lipids yields (more or less) energy per weight of starting material

A

more energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Fats are first broken down to ______ and ____

A

glycerol and free fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

each fatty acids is joined to ___ yielding a ___ at the cost of one ATP

A

coenzyme A,,, fatty acyl CoA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

The fatty acids are then degraded in a stepwise oxidative process, two carbons at a time. each round of oxidation also yields _____ NADH and _____ FADH2

A

one NADH

one FADH2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

the acetyl coA then enters the ______. the net gain is ____ ATPs per molecules of 16 carbon fatty acid. (compared to net gain of 38 ATPs per molecule of glucose

A

enters the citric acid cycle

net gain of 130 ATPS per molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

most of the energy from the breakdown of carboyhydrates or fats is dervided by ______ and ____

A

electron transport

oxidative phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Electrons from NADH and FADH2 are transferred to O2 which is coupled to the formation of

A

34 ATP by oxidative phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

to harvest the free energy in a usuable formthe process is gradual as electrons pass through a series of carriers, which constitute the

A

electron transport chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

components of the ______ are organized into ____ complexes in the inner mitochondrial membrane

A

electron transport chain

four complexes

NOTE INNER MITOCHONDRIA MEMBRANE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

NADH is produced in the krebs cycle in the ___ of the mitrochondria

A

matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

electrons from NADH enter the electron transport chain at _____

A

complex I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

electrons are transferred to _____ by Coenzyme _ (ubiquinone)`

(mitrochondria)

A

complex III by coenzyme Q

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

_____ then carries electrons to complex IV (______) where they are transferred to O2

(mitrochondria)

A

cytochrome c then carries electrons to complex IV cytochrome oxidase, where they are transferred to O2

Note the energy yielding electron transfers at each step are coupled to ATP synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

passage of electron through complexes I, III, and IV drives synthesis of ATP by

A

oxidative phosphorylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

the energy derived from _____ coupled to the generation of a _______ across the inner mitochondrial membrane

A

electron transport

protein gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

electron transport through complexes I, III, and IV is coupled to the transport of protons out of the interior of the mitrochondrion, establishing a _______ across the mitochondrial membrane

A

proton gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

In complex IV,

__ proton per pair of electron are pumed across
__ combine with O2 to form H2O in the matrix

thus ___ protons per pair of electrons are transported at each complex

A

2 protons
two

4 protons per pair of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

the proton gradient is an

A

electrochemical gradient

48
Q

the phospholipid bilayer is impermeable to ions, so protons can cross the membrane only through ________________-

A

protein channels

49
Q

both the ________ and the _______ drive the protons back into the matrix, they combine to form an _________ across the inner membrane

A

pH gradient and the electric potential

for an electrochemical gradient

50
Q

protons can cross the membrane only through a ______________

A

protein channel

51
Q

The protein channel allows energy in the electrochemical gradient to be harnessed and converted to ATP in complex V , also called __________

A

ATP synthase

52
Q

ATP is generated as protons move with the concentration gradient through ______________ which is ____________

A

complex V

ATP synthase

53
Q

ATP synthase consists of two components:

A

F0 forms a spinning channel through which protons pass

F1 spins and harvests the free energy by catalyzing the synthesis of ATP

54
Q

_____ converts the energy of sunlight to a usable form of chemical energy

A

photosynthesis.

note it is ultimately the source of all metabolic energy in biological systems

55
Q

What is the overall equation for photosynthesis

A

6CO2+6H2O—> C6H12O6+6O2

56
Q

the process takes place in two stages: ___ reactions and _____ reactions

A

light and dark

57
Q

light reactions: sunlight energy drives synthesis of ____ and ___ coupled to the oxidation of H2O to ____

A

ATP and NADPH

oxidation of H2O to O2

58
Q

Dark reactions: the ATP and NADPH drive synthesis of carbohydrates from

A

CO2

59
Q

in eukaryotic cells both light and dark reactions occur in what organelle?

A

chloroplast

60
Q

sunligh is absorbed by ______ pigments, such as chlorophylls

A

photosynthetic

61
Q

Absorption of light excites an ____ to a higher energy state, thus converting the energy of sunlight to the potential chemical energy

A

electron

62
Q

the pigments are organized into _____ in the chloroplast membrane

A

photocenters

63
Q

hundreds of pigment molecules absorb photons and transfer energy to _______________

A

reaction center chlorophyll

64
Q

excited electrons are then transferred to an acceptor in the ______–

A

electron transport chain

65
Q

in light reactions, energy from sunlight is used to split

A

H2O to O2

66
Q

in light reactions, the resulting high energy electrons are then transported through a series of carriers and used to convert NADP + to _________

A

NADPH

67
Q

in light reactions, the energy from the electron transport reactions also drive __________-

A

ATP synthesis

68
Q

chloroplast have an internal membrane system, the _____________-

A

thylakoid membrane

69
Q

the thylakoid membrane divides chloroplast into three internal compartments

A

stroma, intermembrane space, thylakoid lumen

70
Q

four proteins complexes in the ___________ function in electron transport and synthesis of _____ and ________

A

thylakoid membrane,

synthesis of ATP and NADPH

71
Q

photons of light energy are absorbed by photosystems __ and ___

A

photosystems I and II

72
Q

in the first electron transport pathway:

at photosystem _____, H2O is split and the resulting electrons enter the transport chain

A

photosystem II

73
Q

in the first electron transport pathway

photo-system _____ generates NADPH, which is required for converting CO2 to carbohydrates

A

photosystem I

74
Q

in the first electron transport pathway:

photosystem ____and _______ complex generates a proton gradient that drives synthesis of ATP

A

Photosystem II and cytochrome bf complex

75
Q

in a second electron transport pathway,

cyclic electron flow, light absorbed at photosystem ____ is used to ____ instead of NADPH

A

cyclic electron flow, ligh absorbed at photosystem I is used to generate ATP instead of NADPH

76
Q

in a second electron transport pathway,

high energy electrons are transported back to the ____ complex and coupled to establishment of proton gradient

A

cytochrome bf complex

77
Q

the energy in the proton gradient is almost entirely ______?

A

chemical

78
Q

the thylakoid membrane is impermeable to other _____, particulary Mg+2 and Cl-

A

other ions

79
Q

free passage of these ions neutralizes the voltage component of the _________

A

proton gradient

80
Q

the difference in PH units between the stroma and the thylakoid lumen can be more then ?

A

3 Ph units

81
Q

the total free energy stored across the thylakoid membrane is similar to that stored across the inner mitochondrial membrane? (true or false)

A

true

82
Q

for each pair of electrons transported, ______ protons are transferred at photosystem II and _____ protons at cytochrome bf complex

A

2 protons are transferred at photosystem II

2-4 protons at cytochrome bf complex

83
Q

since ___ protons are needed for synthesis of 1 ATP each pair of electrons yeilds ___ to ___ ATP

A

4 protons are needed for synthesis of 1 ATP

each pair of electrons yields 1 to 1.5 ATP

84
Q

cyclic electron flow yields____ ATP per pair of electrons

A

1 ATP per pair of electrons

85
Q

in the dark reactions,

the ATP and NADPH produced in the light reactions drive _________ from _________-

A

reactions drive synthesis of carbohydrates from

Co2 and H2O

86
Q

one molecule of Co2 at a time is added to a cycle of reactions, the ______ cycle which leads to the formation of carbohydrates

A

calvin cycle

87
Q

the calvin cycle consumes________ for each glucose produced

A

18 ATP and 12 NADPH

88
Q

____ electrons are needed to convert each molecule of NADP+ to NADPH

A

two electrons

89
Q

these electrons come from the conversion of ____ to ____

A

H20 to O2

90
Q

energy from the breakdown of organic molecules (catabolism) drives synthesis of other components in the cell (true or false?)

A

true

91
Q

____ pathways involve oxidation of organic molecules coupled to generation of ATP and reducing power (NADH)

A

catabolic pathways

92
Q

____________ pathways use ATP and reducing power (NADH or NADPH) for the production for new organic compounds

A

anabolic or you can call it biosynthetic pathway

an example would be dark reactions`

93
Q

in animal cells,

glucose synthesis (____________) usually starts with ??????????

A

gluconeogenesis

this can usually start with:

  • lactate (from anaerobic glycolysis)
  • amino acids (From breakdown of protiens
  • glycerol (from breakdown of lipids)
94
Q

plant cells can synthesize glucose from _______

A

fatty acids

95
Q

in seed germination: energy stored as fats must be converted to carbohydrates for growth of the new plant. This is why it is important that plant cells can synthesize glucose from fatty acids. (true or false)

A

true

96
Q

in ________ pyruvate is converted to glucose

A

gluconeogenesis

97
Q

Gluconeogenesis is not simply the reversal of glycolysis pathways, it requires more energy to drive the pathway in direction of _______

A

biosynthesis

98
Q

glucose is stored in the form of ___________

A

starch and glycogen

99
Q

the dehydration reaction that ______ is energetically unfavorable, and must be coupled to an energy yielding reaction

this is accomplished by the use of __________

A

joins two sugar molecules

nucleotide sugars as intermediates

100
Q

glucose is phosphorylated, then reacts ________, yielding _________

A

glucose is phosphorlyated the nreacts with UTP (uridine triphosphate) yeilding UDP glucose

101
Q

____ glucose is and activated intermediate that then donates its glucose to a growing polysaccharide chain

A

UDP- glucose

102
Q

proteins and nucleic acids contain ______. different organisms use different sources of _____

A

nitrogen

103
Q

some bacteria uses atmospheric N2 by a process called _______, in which N2 is reduced to NH3. ATP is required

A

nitrogen fixation

104
Q

most bacteria, fungi and aplants can use ____ which is common constituent of soil, by reducing it to NH3

A

nitrate NO3-

105
Q

all organisms are able to incorporate _____ into organic compounds

A

ammonia

106
Q

NH3 is incorporated during synthesis of the amino acids _____________

A

glutamate and
glutamine

these amino acids then donate amino groups to other amino acids, which are derived from intermediates in glycolysis and the citric acid cycle

107
Q

bacteria and plants can synthesize all ____ amino acids

A

20

108
Q

humans and other mammals can make only about half of the required _______, the remainder must be obtained from dietary sources

A

amino acids

109
Q

synthesis of protiens also require energy? (true or false?)

A

true

110
Q

unlike polysaccharide synthesis, amino acids are incorporated into protiens in a ____ order, specified by the order of nucleotide bases in a gene

A

unique order

111
Q

what type of RNA acts as a template for protien synthesis?

A

messenger RNA, mRNA

112
Q

each amino acid is attached to a specific __________ molecule in a reaction coupled to ATP hydrolysis

A

transfer RNA (tRNA)

113
Q

__________ then align on the mRNA template, and each amino acid is added to the peptide chain is also coupled to the hydrolysis of _________-

A

the aminoacyl-tRNAS

hydrolysis of ATP and GTP

114
Q

nucleotides can come from dietary sources or from nucleic acid break down or be synthesized from ____________

A

carbohydrates and amino acids

115
Q

synthesis of starts with ________. different pathways lead to synthesis of purine and pyrimidine ribonucleotides

A

ribose-5 phosphate