respiration Flashcards
1
Q
energy required for life processes is derived from
A
oxidation of macromolecules
2
Q
organisms which can produce their own food
A
green plants and cyanobacteria
3
Q
chemical energy derived from light energy by photosynthesis is stored in
A
bonds of carbohydrate, glucose, starch
4
Q
only containing __ photosynthesize
A
chloroplast
5
Q
chloroplasts are located in
A
superficial layers
6
Q
why does food have to be translocated to different parts of plants
A
all non green parts of plants also require food for oxidation
7
Q
saprophytes are dependent on
A
dead and decaying matter
8
Q
ultimately all food that is respired for l life processes comes from
A
photosynthesis
9
Q
what is cellular respiration
A
mechanism of breakdown of food materials for release of energy and storage of this energy for synthesis of atp
10
Q
breakdown of complex molecules for release of energy occurs in
A
cytoplasm and mitochondria only in eukaryotes
11
Q
what is respiration
A
breaking of carbon carbon bond of complex compounds through oxidation within the cells for the release of energy
12
Q
compounds oxidised during respiration are called
A
respiratory substrate
13
Q
preferred respiratory substrate
A
carbohydrate
14
Q
floating respiration
A
fats or carbohydrate
15
Q
protoplasmiic respiration
A
protein
16
Q
when are compounds other than carbohydrates used as respiratory substrate
A
in some plants under certain conditions
17
Q
how is the energy released in the cell after oxidation
A
in a series of slow step wise reactions controlled by enzymes and stored as chemical energy as atp
18
Q
can energy released by oxidation by used directly
A
no only indirectly by synthesising atp which is broken down when it needs to be utilised
19
Q
maximum energy is released by
A
fats
20
Q
instant source of energy
A
carbohydrate
21
Q
what is the energy currency of cell
A
atp
22
Q
carbon skeleton produced during respiration is used as
A
precursor for biosynthesis or other molecules in cell
23
Q
plants have a system which ensures
A
availablity of o2
24
Q
plants have no
A
special organs for gaseous exchange
25
what do plants have as structures for respiration
stomata, lenticels
26
1st reason why plants get along without respiratory organs
each plant part takes care of its own gaseous exchange, there is very little transport of gases from one part of plant to another
27
2nd reason
plants do not have great need for gas exchange, roots, stems and leaves respire at rates far slower than animals, only during photosynthesis large volumes of gas is required, availablity of o2 is not a problem as o2 is released inside the cell
28
3rd reason
distances that plants must diffuse in large bulky plants is not much each living cell in a plant is located quite close to the surface of plant
29
30
arrangement of living cells in stems
organised in thin layers inside and beneath bark with openings called lenticels
31
cells in the interior of stem
are dead and provide mechanical support
32
33
most cells of a plant have
atleast a part of their surface in contact with air
34
which tissue provides an interconnected network of air spaces
loose parenchyma cells in leaves, stems and roots
35
36
the complete combustion of glucose gives out
co2, h20, and energy which i is given out as heat
37
how does plant make sure that all energy liberated does not turn into heart after catabolizing a glucose molecule
oxidise glucose in multiple steps, enabling some steps to be large enough such that the energy l liberated can be coupled to atp synthesis
38
all living organisms retain the enzymatic machinery to
partially oxidise glucose without help of oxygen
39
the scheme of glycolysis was given by
embden, meyerhof, parnas emp pathway
40
in anaerobic organism the only process of respiration
emp pathway
41
where does glycolysis occur
cytoplasm present in all living organisms
42
in glycolysis glucose undergoes
partial oxidation into 2 molecules of pyruvic acid
43
in plants glucose is derived from
sucrose, end product is photosynthesis or from storage carbohydrates
44
45
all enzymes of glycolysis are found in
cytoplasm
46
sucrose is converted into glucose and fructose by enzymes
invertase
47
which monosaccharides enters the glycolic pathway
fructose and glucose
48
glucose and fructose are phosphorylated to form
glucose6 phosphate by use of 1 atp in the presence of enzyme hexokinase
49
glucose 6 phosphate is converted into
fructose1,6 phosphate in the presence of enzyme isomerase
50
fructose1,6 phosphate is converted into
fructose 1,6 biphosphate by use of 1 atp in the presence of enzyme phosphofructokinase
51
how many steps are there in glycolysis
10 enzyme controlled steps
52
fructose 1,6 biphosphate is split into
phosphoglyceraldehyde , dihydroxy acetone phosphate in the presence of enzymes aldolase
53
phosphoglyceraldehyde is covered into
1,3 biphosphoglyceric by reduction of nad to nadh2, in presence of enzymes pga dehydrogenase
54
55
1,3 biphosphoglyceric acid is converted into
3 phosphoglyceric acid by formation of atp in presence of enzymes bga kinase
56
3 phosphoglyceric acid is converted into
2 phosphoglyceric acid in p presence of enzymes mutase
57
2 phosphoglyceric acid is converted into
phosphoenolpyruvate in o presence of enzymes enolase
58
pep is converted into
pyruvic Acid by formation of 1 atp in presence of enzyme pepkinase
59
what is the product of glycolysis
pyruvic Acid
60
what are the ways pyruvic acid is used
alcoholic fermentation, lactic acid fermentation, aerobic respiration
61
fermentation takes place under
anaerobic conditions in many prokaryotes and unicellular eukaryotes
62
for the complete oxidation of glucose, organisms adopt
krebs cycle which is carried as aerobic respiration which requires o2 supply
63
64
65
in fermentation, by yeast oxidation of glucose is achieved under anaerobic conditions where pa is converted into
co2 and ethanol
66
which enzymes catalyse fermentation
pa decarboxylase, alcohol dehydrogenase
67
organisms like bacteria produce
lactic acid from pa
68
in muscles when o2 is insufficient pa is
reduced to lactic acid by lactate dehydrogenase, reducing agent nadh2
69
in both lactic acid and alcohol fermentation
not much energy is released, less than 7 percent of energy in glucose is released
70
lactic acid and alcohol fermentation are ___
hazardous in nature
71
yeast poison themselves to death when concentration of alcohol reaches
13 percent
72
aerobic respiration is most common in
higher plants
74
for aerobic respiration, pa is transported to
mitochondria
75
what is link reaction
link between glycolysis and krebs cycle
76
site of link reaction
Matrix of mitochondria
77
in link reaction pa undergoes
oxidative decarboxylation
78
reactions catalysed by pa dehydrogenase require participation of
coA and NAD
79
the acetyl coA produced by link reaction enters
krebs cycle or tca cycle
80
81
tca cycle starts with the
condensation of acetyl group with oaa and water
82
first product of tca
Citric acid
83
condensation of acetyl group is facilitated by enzymes
citrate synthase
84
citrate is isomerized to form; enzym3
isocitrate ; aconitase
85
isocitrate decarboxylases to form
alpha keto glutaric acid, nad reduces to nadh2, enzyme is isocitrate dehydrogenase, co2 is removed
86
alpha keto glutaric acid changes to
succinyl coA, nad is reduced to nadh2, co2 is removed, enzyme is Substrate dehydrogenase
87
succinyl coA change to
succinic acid, gtp is formed, enzyme is thiokinase
88
succinuc acid changes to
funeric acid, fad changes to fadh2, enzyme is succinic acid dehydrogenase
89
succinic acid changes to
fumeric acid, enzyme is
90
fumeric acid changes to
malic acid enzyme is fumerase
91
malate changes to
oaa , fad changes to fadh2, enzyme is malate dehydrogenase
92
all enzymes of krebs cycles are found in ; except
Matrix of mitochondria except succinic dehydrogenase which is found in imm
93
94
steps in which energy stored in nadh2 and fadh2 is utilised and released
electron transport system
95
when is electron transport system accomplished
when nadh2 and fadh2 are oxidised through ets and electron are passed to oxygen resulting in formation of h20
96
the metabolic pathway through which the electrons pass from one electron carrier to another is called
electron transport system/oxidative phosphorylation
97
ets occurrs in
inner mitochondrial membrane
98
electron from nadh are produced where in tca
Matrix of mitochondria
99
in ets electron from nadh are
oxidised by nadh dehydrogenase age electrons are transferred to ubiquinone
100
in ets ubiquinone also receives
reducing equivalents from fadh2 that is generated during oxidation of succinic acid in tca
101
the reduced ubiquinone is
then oxidised with further transfer of electrons to cytochrome c by complex cytochrome bc complex
102
what is cytochrome c
small protein attached to outer side of the immm , acts as a mobile electron carrier by between 3 and 4 complex
103
complex 4 is
cytochrome a,a3 cytochrome c oxidase complex with 2 copper centres
104
when electrons pass from one carrier to another via complex 1 to 4 in the ets they are
coupled to atp synthase(complex 5) for production of atp from adp and inorganic phosphate
105
although the aerobic process of respiration takes places only in presence of oxygen in ets the role of oxygen
its limited to the terminal stage o of the process
106
the presence of oxygen is vital in ets because
it drives the process by removing hydrogen from the system
107
what is the final hydrogen acceptor in ets
oxygen
108
how is a proton gradient made in ets
by energy of oxidation reduction
109
energy released in during electron transfer in ets is utilised in
the synthesis of atp
110
f1 headpiece of atp synthase
peripheral membrane protein complex, contains site for synthesis of atp from adp and ip
111
f0 of atp synthase
integral membrane protein complex, forms the channel through which protons enter the inner membrane
112
the passage of proton through the channel is coupled to
catalytic site of f1 component
113
for each atp produced
4H pass from f0 from ims to matrix down there electrochemical gradient
114
115
under what assumptions can calculations of atp be made
there is a sequential orderly pathway , with one substrate forming after another and with glycolysis, tca and ets following ones after another
nadh synthesized in glycolysis is transferred to mitochondria for oxidative phosphorylation
none of the intermediates are utilised to synthesize another compound
only glucose is being required no other substrates enter the pathway
116
in fermentation, nadh is oxidised rather
slowly
117
what is the favoured substrate for respiration
glucose
118
all carbohydrates are usually first converted into
glucose
119
do substrate other than glucose enter the pathway at c the first step
no
120
fats need to be broken down into
fatty acids and glycerol
121
proteins are converted into
amino acids
122
glycerol would enter the pathway after being converted to
pgal
123
proteins would be degraded by
proteases and individual amino acids after deamination would enter the pathway at some stage within the krebs cycle as pyruvate or acetly coa
124
when organisms need to synthesize fatty acid
amino acids would be withdrawn from the pathway
125
respiratory pathway can be considered a
amphibolic pathway
126
ratio of volume of co2 evolved to the volume of o2 consumed is called
respiratory quotient
127
respiratory quotient depends on
type of substrate used
128
for carbohydrate rq is
1
129
when fats are used rq is
less than 1
130
when proteins are used rq is
0.9
131
in living organisms respiratory substrate are often
more than one
132
are pure proteins and fats used as respiratory substrates
no
133
134
one atp yields
34kJ/mol
135
total energy obtained from 38 atp is
1292kJ/mol
136
how much energy does glucose store
2870kj/mol
137
efficiency of respiration
45%:- 1292/2870×100
138
rq for organic acids
more than one
139
rq for oxalic acid
4
140
rq for malic acid
1.33
141
for anaerobic respiration
infinity
142
can acetly coa be considered a high energy molecule
yes
143
144
