Cell Respiration Flashcards
exchange of gases in the environment
respiration
describe the route of transport of oxygen from the outside to the inside of your body
lungs > blood stream > tissues > cells > mitochondria
reaction in which energy is absorbed
endergonic
modified nucleotide
adenosine triphosphate
How many times can an ATP molecule release energyt
twice
3 major steps in cellular respiration
glycolysis
krebs cycle
electron transport chain
glucose is broken down
glycolysis
takes place in the cytoplasm
anaerobic respiration
6-c glucose is converted to what
2 molecules of pyruvates (3-C)
oxygen is not yet needed
anaerobic
the cell has to utilize ATP to start the process
energy investment phase
production of 4 ATPs
energy payoff phase
net yield of glycolysis
2 ATPs
concentrate the energy into the bonds of ATP
reactions in catabolic pathways
convenient energy carrier
ATP
generally has “high-energy” and unstable bonds
ATP
similar to a highly flammable liquid such as kerosene, which is easier to ignite and provides heat more quickly and convenient
ATP
unstable bond part of ATP that provide the cell with readily available energy for anabolic (synthetic) reactions
“high-energy” molecule
Two general aspects of energy production:
oxidation-reduction mechanisms
ATP generation mechanisms
ATP generation mechanisms include
Oxidative or electron transport level phosphorylation
substrate level phosphorylation
photophosphorylation
ATP is composed of what
nucleoside (adenosine, ribose)
3 phosphate
in this, energy in organic molecules is extracted when they transfer 2 hydrogen atoms
oxidation
hydrogen composed of 2 electrons and protons
2 hydrogen atoms
composed of 2 electrons and protons
coenzyme NAD
Coenzyme NAD+ - receives 1 electron (-) hence, it is reduced and cancels its + charge; and one hydrogen atom making it
NADH
a more energy-rich molecule
NADH
the remaining of this is released to the environment
Hydrogen ion
Every NAD+ that is reduced to NADH, what happens to the extra H+
an extra H+ is released in the process
used by cells in catabolism to extract energy in the form of electrons from nutrient molecules
redox reactions
take nutrients as energy sources and degrade them from highly reduced compounds to fully oxidized compounds
cells
converted to pyruvic acid after a series of steps in glycolysis
glucose
said to have been oxidized along with the reduction of NAD+ electron carriers, among others
glucose
where the reduced electron carriers will proceed to convert energy from the electrons to ATP
Electron transport level phosphorylation
generated in several ways in the cells during respiration, and also during photosynthesis
ATP
also known as oxidative phosphorylation owing to the oxidation-reduction that follows along the electron transport chain
ETLP
in ETLP, this is generated when the electrons from the carriers (e.g. NADH) are carried forward and tossed to the ETC simultaneous with the transport of H+ to the other side of the membrane
ATP
NAD
(Nicotinamide adenine dinucleotide)
FAD
(flavin adenine dinucleotide)
represent the oxidized form of electron carriers
NAD and FAD
NAD and FAD accept a pair of electrons and hydrogen atoms and get converted to their reduced forms
NADH and FADH2
was built after the movement of H+ ions into the other side of the membrane
concentration gradient
as this receives and passes on electrons, they too become reduced and oxidized in the process
ETC
last to receive the de-energized electrons (hence, aerobic respiration)
oxygen
formed when the de-energized electrons couples with the oxygen
water
allows the passive movement of H+ concentration gradient, the energy of the flow is then used to synthesize ATP from ADP and phosphate
ATP synthase
SLP
Substrate Level Phosphorylation
in this mechanism, ATP is usually generated when a high-energy phosphate is directly transferred from a phosphorylated compound to ADP
SLP
this must have gotten its phosphate from an earlier reaction where a substrate must have been oxidized in its favor
phosphorylated compound
this happens in cells during photosynthesis’ light-dependent reactions
photosynthesis
this happens in cells during photosynthesis’ light-dependent reactions
light energy
where the molecules’ electrons jump from one
to another, an ETC similar to that in respiration
carrier proteins
in photophosphorylation, the energy of electrons is used by this to pass along protons (H+) and these are allowed to flow back just like in oxidative phosphorylation
ETC
involves a pathway from the complete breakdown of glucose to carbon dioxide and water
cell respiration
Three major steps of cell respiration
glycolysis
krebs cycle
ETC
glycolysis is divided into two parts
energy investment phase
energy payoff phase
requiring the investment of 2 ATPs
energy investment phase
generates 4 ATPs through substrate-level phosphorylation
Energy payoff phase
net product produced in glycolysis
2 ATP
in glycolysis is very important especially when oxygen becomes short in supply
SLP
cells wherein oxygen can become short in supply
muscle cells
muscle cells rely on this during rapid contraction, and oxygen delivery to tissues cannot supply the requirement of ETLP
glycolysis
accumulates in the tissues and is later metabolized in the liver
lactic acid
after strenuous activity repays the oxygen debt that has occurred
rapid breathing
converts the pyruvate into acetyl-CoA
preparatory step
enters the Krebs Cycle or Citric Acid cycle
Acetyl-CoA
at the end of the Krebs Cycle, this much ATP are produced by SLP
2 ATPs
in step 3, these from the first two steps (glycolysis and krebs cycle) are tossed to the ETC
reduced carriers
in step 3, generates 34 ATPs
ETC
total amount of ATPs per glucose molecule produced
36-38 ATPs
how many ATP is consumed in the energy investment phase in glycolysis
2 ATP
how many ATP is produced through SLP in the energy payoff phase in glycolysis
4 ATP
how many NADH is produced in oxidative phosphorylation the glycolytic pathway
2 NADH
how many ATP can be produced from 1 NADH
3 ATP
how many ATPs can be produced in the glycolytic pathway with 2 NADH
6 ATP
how many ATP is produced in the Krebs Cycle through SLP
2 ATP
is the entry source of energy in glycolysis
glucose
are invested in the energy investment phase to fulfill the conversion of the molecules to PGAL or DHAP
2 ATPs
are inconvertible
PGAL and DHAP
PGAL
3-phosphoglyceraldehyde
DHAP
dihydroxyacetone phosphate
also known as PGAL, can enter the second phase of glycolysis
3-glyceraldehyde phosphate
how many ATPs are produced in the second phase of glycolysis
4 ATPs
in this phase in glycolysis, oxidizes intermediate substrates
energy payoff phase
how many NADH is produced in the energy payoff phase of glycolysis
2 NADH
translated into 3 ATP by ETLP at the ETC
NADH
end product of glycolysis
2 pyruvic acid/pyruvates
is also called the tricarboxylic acid (TCA) cycle or citric acid cycle
Krebs cycle
series of biochemical reactions that releases large amount of potential energy in acetyl coA in step by step manner
krebs cycle
the reaction that happens in the Krebs cycle wherein the electrons are transferred to electron carriers
redox reaction
just like in glycolysis, the carriers take the electrons to the ETC for ATP conversion
carriers
in Krebs cycle, are recycled and it can go on continuously as long as the entry molecules, enzymes, and intermediates are available
intermediates
pyruvic acid is converted into this in the Krebs cycle
acetyl
the Acetyl is attached to this
coenzyme A (CoA)
pyruvic loses this due to decarboxylation
carbon molecule
major outcomes of the krebs cycle
release of CO2 molecules (decarboxylation)
oxidation-reduction reactions to transfer electron to carriers
SLP
carried by the blood to the lungs and is liberated to the atmosphere through exhalation
CO2
(fully stripped of its energy and oxidized to CO2)
decarboxylated
from the previous steps are carried forward and tossed to the ETC while simultaneously transporting H+ to the other side of the membrane using the energy of the electrons
NADH
receiving and passing on the electrons along its length
electron transport complexes
absorbs the weakened electrons, then chemically react with two hydrogen ions to form water
oxygen
where it tosses its electrons, resulting in lower ATP coinversion
FADH2
conversion rate of FADH2
2 ATPs
conversion rate of NADH
3 ATP
uses the flow of H+ concentration gradient to synthesize ATP from ADP and phosphate
ATP synthetase
its oxidation to acetyl CoA is a transition step which prepares it for entrance into the Krebs cycle
pyruvate
during this, glucose is broken down, producing CO2, H2O, and ATP
aerobic cellular respiration
very important in that they shuttle electrons to the ETC for the synthesis of ATP
NADH and FADH
can be deducted from the net ATP due to it being spent on active transport of acetyl coA
2 ATPs
becomes the starting material for metabolic processes
glucose
requires oxygen from the atmosphere
aerobic respiration
where glucose can be derived from
starch or glycogen
describe the equation where glucose is converted to energy through cellular respiration
Glucose + O2 -> CO2 + H2O + energy
dinucleotide with nicotinamide
NAD/NADH
facilitates the breakdown of glucose
dehydrogenase
where glycolysis occurs
cytoplasm
glycolysis is a what metabolic pathway
anaerobic
how many enzymes is required in glycolysis
10 enzymes
first step in glycolysis
hexokinase reaction
first enzyme in glycolysis that phosphorylates the oxygen on carbon 6 to make glucose-6-phosphate
hexokinase
hexokinase catalyzes glucose’s conversion to this
glucose-6-phosphate
causes more glucose to enter the cell, costs 1 ATP
phosphorylation
catalyzed by phosphoglucoisomerase
isomerization
second enzyme in glycolysis that catalyzes glucose-6-phosphate to isomerize to fructose-6-phosphate
phosphoglucoisomerase
Phosphoglucoisomerase catalyzes glucose-6-phosphate to this
fructose-6-phosphate
third step in glycolysis
second phosphorylation
steps in glycolysis where ATP is consumed
phosphorylation
where the second phosphorylation occurs
carbon-1 hydroxyl
third enzyme in glycolysis that catalyzes the conversion of fructose-6-phosphate to fructose-1, 6-bisphosphate
phosphofructokinase 1
phosphofructokinase 1 catalyzes fructose-6-phosphate to this
fructose-1, 6-bisphosphate
step 4 wherein the molecules are ready to be cleaved into two smaller ones
cleavage
lyase enzyme that will split fructose-1, 6-bisphosphate into glyceraldehyde-3-phosphate (GADP) and dihydroxyacetone phosphate (DHAP)
fructose bisphosphate aldolase
fructose bisphosphate aldolase will split fructose-1, 6-bishphosphate into this
3-phosphoglyceradehyde and dihydroxyacetone phosphate
step 5 of glycolysis
conversion of DHAP to PGAL
converts DHAP to GADP/G3P/PGAL
triosephosphate isomerase
sixth step in glycolysis
oxidative
is oxidized into 1,3-bisphosphate by glyceraldehyde phosphate dehydrogenase
GADP/G3P
enzyme involved in the oxidation of G3P to 1,3-bisphosphate
glyceraldehyde phosphate dehydrogenase
step 7 of glycolysis where an ATP is produced
dephosphorylation
catalyze the transfer of a phosphate group in 1-3-bisphosphoglycerate to ADP to become 3-phosphoglycerate
phosphoglycerate kinase
since each of these will make one ATP, there will be 2 ATP molecules created in step 7
2 GADP molecules
step 8 In glycolysis where phosphoglycerate mutase transfers the phosphate from 3-phosphoglycerate to make 2-phosphoglycerate
phosphate transfer
transfer the remaining phosphate from 3-phosphoglycerate to make 2-phosphoglycerate
phosphoglycerate mutase
step 9 where enolase catalyzes this resulting in the loss of a hydroxyl group which will produces phosphoenolpyruvate.
dehydration
catalyzes a dehydration which will reduce 2-phosphoglycerate to phosphoenolpyruvate
enolase
step 10 where the remaining phosphate group is transferred to an ADP by pyruvate kinase
second dephosphorylation
transfers the remaining phosphate group to an ADP from the phosphoenolpyruvate to become pyruvate
pyruvate kinase
where another ATP is generated (2 in total)
second dephosphorylation
all together, glyoclysis is a what
10 step process
how many steps are the preparatory phase of glycolysis
5 steps
describe the preparatory phase of glycolysis
Glucose + 2 ATP -> GADP
describe the payoff phase of glycolysis
2 GADP -> 2 pyruvate + 4 ATP
state the reactant, product, enzyme, and addtl details of the first step of glycolysis
glucose
glucose-6-phosphate
hexokinase
spends 1 ATP
state the reactant, product, enzyme, and addtl details of the second step of glycolysis
glucose-6-phosphate
fructose-6-phosphate
phosphoglucoisomerase
state the reactant, product, enzyme, and addtl details of the third step of glycolysis
fructose-6-phosphate
fructose-6, 1-bisphosphate
phosphofructokinase 1
cost 1 ATP
state the reactant, product, enzyme, and addtl details of the fourth step of glycolysis
fructose-6, 1-bisphosphate
3-phosphoglyceraldehyde, dihydroxyacetone phosphate
fructose bisphosphate aldolase
state the reactant, product, enzyme, and addtl details of the fifth step of glycolysis
dihydroxyacetone phosphate
3-phosphoglyceraldehyde
triosephosphate isomerase
state the reactant, product, enzyme, and addtl details of the sixth step of glycolysis
3-phosphoglyceraldehyde
1,3-bisphosphoglycerate
glyceraldehyde phosphate dehydrogenase
cost 1 NAD
state the reactant, product, enzyme, and addtl details of the seventh step of glycolysis
1,3-bisphosphoglycerate
3-phosphoglycerate
phosphoglycerate kinase
producest 1 ATP
state the reactant, product, enzyme, and addtl details of the eighth step of glycolysis
3-phosphoglycerate
2-phosphoglycerate
phosphoglycerate mutase
state the reactant, product, enzyme, and addtl details of the ninth step of glycolysis
2-phosphoglycerate
phosphoenolpyruvate
enolase
state the reactant, product, enzyme, and addtl details of the tenth step of glycolysis
phosphoenolpyruvate
pyruvate
pyruvate kinase
produces 1 ATP
where aerobic respiration occurs
mitochondria
proposes that mitochondria were once separate organisms that were incorporated in eukaryotes
endosymbiotic theory
where the pyruvates enter after glycolysis
mitochondrial matrix
In the presence of NAD+, pyruvate will undergo:
decarboxylation (release of CO2)
oxidation by NAD
attachment to coenzyme A
pyruvates will enter the mitochondrial matrix to find this
coenzyme A
is generated when coenzyme A attaches to the pyruvate
acetyl coA
Acetyl CoA enters this
citric acid cycle
8-step pathway requiring 8 separate enzymes
krebs cycle
first enzyme in the krebs cycle that removes the acetyl group and tacks it on to oxaloacetate to form citrate
citrate synthase
removes the water molecule from citrate and another one is added to generate a structural isomer
aconitase
structural isomer of citrate
isocitrate
catalyzes the oxidation of isocitrate by NAD+ and decarboxylates to form alpha-ketoglutarate
isocitrate dehydrogenase
aids in the process of losing another CO2 and further oxidation by NAD+ takes place
ketoglutarate dehydrogenase
resulting molecule in step 3 of krebs cycle will join with this once again to form succinyl-CoA
coenzyme A
displaces CoA in the Krebs cycle to form succinate
phosphate group
catalyzes the formation of succinate
succinyl-CoA synthase
GTP
Guanosine triphosphate
can be used to make one ATP
GTP
succinate is oxidized by FAD
succinate dehydrogenase
result of oxidation of FAD and succinate
fumerate and FADH2
will catalyze hydration which will result in malate
fumarase
helps the oxidation by NAD+
malate dehydrogenase
malate dehydrogenase will oxidize malate and result into this, restarting the cycle
oxaloacetate
overall for every acetyl coA that enters, this will produce how many NADHs, FADH2, and ATP
3 NADH
one FADH2
one ATP
for 2 pyruvates entering the krebs cycle, how ma
6 NADH
2 FADH2
2 ATP
state the reactant, product, enzyme, and addtl details of the first step of krebs cycle
acetyl coA + oxaloacetate
citrate
citrate synthase
state the reactant, product, enzyme, and addtl details of the second step of the krebs cycle
citrate
isocitrate
aconitase
one water lost, one water gained
state the reactant, product, enzyme, and addtl details of the third step of the krebs cycle
isocitrate
α-ketoglutarate
isocitrate dehydrogenase
uses one NAD+, produces NADH + CO2
state the reactant, product, enzyme, and addtl details of the fourth step of the krebs cycle
α-ketoglutarate
succinyl CoA
ketoglutarate dehydrogenase
uses one NAD, produces NADH + CO2
state the reactant, product, enzyme, and addtl details of the fifth step of the krebs cycle
succinyl CoA
succinate
succinyl CoA synthetase
uses one phosphate, produces GTP
state the reactant, product, enzyme, and addtl details of the sixth step of the krebs cycle
succinate
fumarate
succinate dehydrogenase
uses one FAD, produces FADH2
state the reactant, product, enzyme, and addtl details of the seventh step of the krebs cycle
fumarate
malate
fumarase
one water gained
state the reactant, product, enzyme, and addtl details of the eighth step of the krebs cycle
malate
oxaloacetate
malate dehydrogenase
uses one NAD, produces NADH
generates by far the biggest energy payoff
oxidative phosphorylation
where oxidative phosphorylation happens
inner membrane of the mitochondrion
these proteins bear a variety of prosthetic groups
proteins complexes I-IV
non-protein components of the protein complexes
prosthetic group
where prosthetic groups gives its functionality
flavin mononucleotides and cytochrome
compound in the ETC that is not a protein, hydrophobic molecule that is mobile within the membrane and is also known as coenzyme Q or CoQ
ubiquinone
feeds electrons on the first components on the ETC
NADH
what happens when NADH feeds electrons on the proteins in ETC
sequential redox reactions
describe the pathway that electrons move through in ETC
PS I
Q PSIII
PSIV
by the movement of electrons through a transport chain, this was produced
proton gradient
they accumulate outside the inner mitochondrial membrane, which then go to power ATP synthase
protons
proton-motive force that can generate ATP through a chemical gradient
chemiosmosis
– structure that has a component that looks startlingly like a rotor, where individual protons can bind and cause it to spin in such a way that
ATP synthetase
A substance with loses electrons is said to be
oxidized
Composed of cyt-b-Fe-s-cyt c1 electron transporters
complex 2
The electron transport system produces ___ ATP from each NADH and/or ____ ATP from each FADH2 entering the system
3;2
In which step of cell respiration does production of majority of ATPs happen?
ETC
Why are mitochondria absent in mature red blood cells
They would consume O2 carried by mature RBCs
NADH transfers e- to this complex
complex 1
The last electron acceptor in the ETC is
oxygen
The primary energy carrier between the citric acid cycle and the electron transport system is
NADH
ATP production characterized by direct transfer of an inorganic phosphate from phosphorylated compound to ADP
substrate level phosphorylation
Which ion gradient provides energy in the production of ATP?
H+
This step happens in the cristae
ETC
Match the event/characteristic to the correct step/stage:
chemiosmosis
formation of 6 NADH
production of 4 ATP
ETC
Krebs
Glycolysis
Which of these processes occur in the cytosol?
glycolysis
Match the event/characteristic to the correct step/stage:
decarboxylation of pyruvate
formation of FADH
energy investment
decarboxylation of pyruvate - prep
formation of FADH - krebs
energy investment - glycolysis
The carbon dioxide we exhale is produced in
citric acid cycle
prep
FADH2 transfers its electrons to cyt c and produces a weaker H+ gradient so that only 2 ATPs can be produced from kinetic energy generated from the said ion gradient
false
ETC is composed of what complexes
complex I
complex II
complex III
ATP synthase
complex I is composed of
FMN
Fe-S
complex II is composed of
cyt b
Fe-S
Cyt c1
complex III is composed of
Cu
Cyt a
Cyt a3
what complex do not belong in CI-CIII
Q
Cyt c
how many CO2 is produced in prep
2 CO2
how many CO2 is produced in krebs
4 CO2
how many NADH is produced in krebs (2 cycles)
6 NADH
how many FADH2 is produced in krebs (2 cycles)
2 FADH
how many ATP is produced in krebs (2 cycles)
2 ATP
Match the event/characteristic to the correct step/stage
anaerobic
production of 2 ATP
CoA attaches to the acetyl group
anaerobic - glycolysis
production of 2 ATPs - Krebs
CoA attaches to acetyl group - prep
Which process reduces molecular oxygen to water
the electron transport system
Complete oxidative breakdown of glucose results in ___ ATP molecules
36 molecules
Match the event/characteristics to the correct step/stage
formation 2 CO2
aconitase
use of 2 ATPs to initiate cell respiration
Formation of 2 CO2 - prep
aconitase - krebs
use of 2 ATPs…- glycolysis
In the ETC, coenzymes are oxidized
True
Match the event/characteristic to the correct step/stage
Coenzymes are oxidized –
Citrate synthase –
Formation of 34 ATPs –
ETC/Glycolysis
Krebs
ETC
These processes occur in the mitochondrial matrix
prep, krebs
Which connects glycolysis with the final stages of the aerobic pathways?
prep
Match the event/characteristic to the correct step/stage
Formation of 2 GTPs ->
Citric acid cycle ->
Aldolase ->
Formation of 2 GTPs -> krebs
Citric acid cycle -> krebs
Aldolase -> glycolysis
Oxidative phosphorylation is less efficient in terms of ATP production compared to fermentation
FALSE
The preparatory reaction breaks pyruvate into what
acetyl-CoA and carbon dioxide
One turn of the citric acid cycle produces
3 NADH, 1 FADH, 1 ATP
Match the event/characteristic into the correct step/stage:
Electron transporters are arranged into complexes ->
Glucose broken down into pyruvates –
Productions 4 CO2 –
electron transporters are arranged into complexes -> ETC
Glucose broken down into pyruvates – glycolysis
Productions 4 CO2 – krebs
The citric acid cycle
Must occur twice for each glucose molecule to be metabolized
- Produces 4 carbon dioxide molecules per glucose molecule - All of the choices are correct
- Produces 2 ATP directly from the cycle intermediates
all are correct
In which step of cell respiration does the utilization of 2 ATPs happen to transport pyruvates into the mitochondrion?
prep
