Download A2 Aerobic respiration Link reaction Glucose cannot cross the

Glycolysis:
Glycolysis occurs in the ______________.
1.
Glucose is activated by the addition of two __________
molecules provided by 2 ATP. This step lowers the
_______________ energy needed for the enzyme
reaction which follows.
_______ + 2 ___ -> phosphorylated glucose + 2 ADP
2.
Phosphorylated glucose is then split into two molecules of
triose phosphate (3C).
phosphorylated glucose  2 Triose phosphate
3.
Triose phosphate is __________ by the removal of
hydrogen, forming _________ ____ and ___________
(3C). Energy is released and used to generate 2 molecules
of ________ from each triose phosphate molecule in a
process called ___________ _______ phosphorylation.
2 Triose phosphate + 2NAD + 4ADP + 2 Pi  2 pyruvate +
2 NADH + 4 ATP
Since 2 ATP were used to activate glucose and 4 ATP are
generated, there is a ____ gain of ___ ATP from each
_____________ molecule used during glycolysis.
A2 Aerobic respiration
Link reaction
Glucose cannot cross the
mitochondrial membranes, but
_______________ is actively
transported into the mitochondrial
matrix from the _____________.
Pyruvate is then ____________ by
the removal of hydrogen which is
accepted by the coenzyme NAD
forming ________ ____. The
remaining portion of the original
pyruvate loses __________
___________ and combines with
coenzyme A to form _______
______________ ___(2 C)
Pyruvate + NAD + coenzyme A 
acetyl coenzyme A + carbon dioxide
+ reduced NAD
Since ______________ produces
2 pyruvate molecules, this step
yields 2 acetyl coenzyme A
molecules + 2 NADH from each
glucose molecule undergoing
glycolysis.
pyruvate; cytoplasm; reduced NAD; acetyl coenzyme A; glucose; carbon dioxide; oxidised; level; 2
phosphate; activation; ATP; glycolysis; substrate; net;
Glycolysis:
Glycolysis occurs in the cytoplasm.
1.
Glucose is activated by the addition of two phosphate
molecules provided by 2 ATP. This step lowers the
activation energy needed for the enzyme reaction which
follows.
Glucose + 2 ATP -> phosphorylated glucose + 2 ADP
2.
Phosphorylated glucose is then split into two molecules of
triose phosphate (3C).
phosphorylated glucose  2 Triose phosphate
3.
Triose phosphate is oxidised by the removal of hydrogen,
forming reduced NAD and pyruvate (3C). Energy is
released and used to generate 2 molecules of ATP from
each triose phosphate molecule in a process called
substrate level phosphorylation.
2 Triose phosphate + 2NAD + 4ADP + 2 Pi  2 pyruvate +
2 NADH + 4 ATP
Since 2 ATP were used to activate glucose and 4 ATP are
generated, there is a net gain of 2 ATP from each glucose
molecule used during glycolysis.
A2 Aerobic respiration
Link reaction
Glucose cannot cross the
mitochondrial membranes, but
pyruvate is actively transported
into the mitochondrial matrix from
the cytoplasm.
Pyruvate is then oxidised by the
removal of hydrogen which is
accepted by the coenzyme NAD
forming reduced NAD. The
remaining portion of the original
pyruvate loses carbon dioxide and
combines with coenzyme A to form
acetyl coenzyme A (2 C)
Pyruvate + NAD + coenzyme A 
acetyl coenzyme A + carbon dioxide
+ reduced NAD
Since glycolysis produces 2
pyruvate molecules, this step yields
2 acetyl coenzyme A molecules + 2
NADH from each glucose molecule
undergoing glycolysis.
pyruvate; cytoplasm; reduced NAD; acetyl coenzyme A; glucose; carbon dioxide; oxidised; level; 2
phosphate; activation; ATP; glycolysis; substrate; net;
Krebs cycle
The Krebs cycle is a series of reduction-oxidation
(redox) reactions which take place inside the
mitochondrial ________________.
_________ __________ __(__C) combines with a
___ carbon molecule to produce a 6 carbon molecule.
The 6 C molecule loses __________ ___________
and some hydrogen in a series of reactions, eventually
reforming the 4 C molecule. _________ is accepted
by 3 _____ to form 3 reduced NAD, and by one
_____ to form reduced FAD. In addition energy is
released to allow the formation of one molecule of ATP
by ____________ _________ ________________.
A2 Aerobic respiration: carbon dioxide; link
matrix; carriers; acetyl coenzyme A; 4
hydrogen; 2; enzymes; amino NAD; substrate
level phosphorylation; cristae; FAD
Mitochondrion: The _____
reaction and Krebs cycle
occur in the ______. The
inner membrane has folds
called __________ which
create a large surface
area for the _______________ of the
electron transport chain.
Coenzymes
Coenzymes are molecules that some
___________ require in order to be able
to function. In respiration ____ works
with several dehydrogenase enzymes that
catalyse the removal of _____________.
The NAD accepts the hydrogen and
transfers it to the carriers involved in the
electron transport chain.
Krebs cycle intermediates: the
intermediate molecules involved in the
Krebs cycle are linked to a number of
additional metabolic pathways helping cells
to synthesise key molecules such as fatty
acids and _____________ acids.
Krebs cycle
The Krebs cycle is a series of reduction-oxidation
(redox) reactions which take place inside the
mitochondrial matrix.
Acetyl coenzyme A (2C) combines with a 4C molecule
to produce a 6 carbon molecule.
The 6 C molecule loses carbon dioxide and some
hydrogen in a series of reactions, eventually reforming
the 4 C molecule. Hydrogen is accepted by 3 NAD to
form 3 reduced NAD, and by one FAD to form reduced
FAD. In addition energy is released to allow the
formation of one molecule of ATP by substrate level
phosphorylation.
A2 Aerobic respiration: carbon dioxide; link
matrix; carriers; acetyl coenzyme A;
hydrogen; 4C; enzymes; amino NAD; substrate
level phosphorylation; cristae; FAD
Mitochondrion: The link
reaction and Krebs cycle
occur in the matrix. The
inner membrane has folds
called cristae which
create a large surface
area for the carriers of the electron
transport chain.
Coenzymes
Coenzymes are molecules that some
enzymes require in order to be able to
function. In respiration NAD works with
several dehydrogenase enzymes that
catalyse the removal of hydrogen. The
NAD accepts the hydrogen and transfers
it to the carriers involved in the electron
transport chain.
Krebs cycle intermediates: the
intermediate molecules involved in the
Krebs cycle are linked to a number of
additional metabolic pathways helping cells
to synthesise key molecules such as fatty
acids and amino acids.
Electron transport chain
Electron transport chain (ETC)
Reduced _______________ produced by
__________, the link reaction and Krebs
cycle are used to synthesise ATP using
the electron transport chain.
Reduced coenzymes pass ___________to
electron carriers located within the
______ membrane of mitochondria. Folds
called _________ create a larger surface
area for attachment of these electron
carriers.
As electrons are passed down the electron transport chain
between carriers, _____________ is released and used to pump
hydrogen ions (H+/protons) into the intermembrane _________.
These ________ then move down an electrochemical gradient via
the __________ ATPase back into the matrix. Energy is used by
the ATP synthase to produce ATP from ____ and ____________
by a process called ___________ ______________.
_____________ is the _____________ electron acceptor in the
electron transport chain and it combines with protons to make
__________.
Each molecule of reduced _________used generates 3 molecules
of ATP, whilst reduced ______________ generates 2 ATP.
Respiratory inhibitors.
Many ______________ of aerobic
respiration interfere with the ETC.
By preventing the transport of
_____________ or the formation
of the proton gradient they stop
ATP synthesis. In this situation
electrons cannot be passed to
___________, so it is not used up.
Also as energy cannot be passed to
generate ATP it is lost as _______,
warming the surroundings further.
In the presence of inhibitors, cells
may still be able to generate some
ATP via ___________ respiration.
Electron transport chain
Electron transport chain (ETC)
Reduced coenzymes produced by
glycolysis, the link reaction and Krebs
cycle are used to synthesise ATP using
the electron transport chain.
Reduced coenzymes pass electrons to
electron carriers located within the
inner membrane of mitochondria. Folds
called cristae create a larger surface
area for attachment of these electron
carriers.
As electrons are passed down the electron transport chain
between carriers, energy is released and used to pump hydrogen
ions (H+/protons) into the intermembrane space. These protons
then move down an electrochemical gradient via the enzyme ATP
synthase back into the matrix. Energy is used by the ATPase to
produce ATP from ADP and phosphate by a process called
oxidative phosphorylation.
Oxygen is the final electron acceptor in the electron transport
chain and it combines with protons to make water.
Each molecule of reduced NAD used generates 3 molecules of
ATP, whilst reduced FAD generates 2 ATP.
Respiratory inhibitors.
Many inhibitors of aerobic
respiration interfere with the ETC.
By preventing the transport of
electrons or the formation of the
proton gradient they stop ATP
synthesis. In this situation
electrons cannot be passed to
oxygen, so it is not used up. Also as
energy cannot be passed to
generate ATP it is lost as heat,
warming the surroundings further.
In the presence of inhibitors, cells
may still be able to generate some
ATP via anaerobic respiration.