Download AP Biology Chapter 9.2016

Cellular Respiration
AP Biology Chapter 9
– start…
• Quick Write…
• On the card you picked up at the
beginning of class write all you know about
“cellular respiration” … its parts, what are
the main components, reactants and
products, its purpose, where it occurs and
which organisms carry out this process!
Warm Up
• Which atom has a stronger affinity for
electrons (ie holds its electrons closer and
tighter to its nucleus)
– Carbon?
– Oxygen?
OR
• How do you know?
Fig. 9-1
How do these leaves
power the work of life
for this chimpanzee?
Coupled Reactions
• What do you remember about the Cotransport of H+ and Sucrose through the
plasma membrane?
• Photosynthesis
• Cellular respiration
– Are they coupled in an ecosystem?
Fig. 9-2
Light
energy
p163
ECOSYSTEM
Photosynthesis
in chloroplasts
CO2 + H2O
Organic
+O
molecules 2
Cellular respiration
in mitochondria
ATP
ATP powers most cellular work
Heat
energy
Cellular Respiration
• The breakdown of glucose is exergonic
• ATP is the result of
– Fermentation (Glycolsis)Anaerobic Respiration)
– Cellular Respiration (Aerobic Respiration)
• ATP is used Cellular work… drives all the
work! Page 149 examples… (ch8)
Respiration Overview
• Photosynthesis is the process of
incorporating energy from light into
energy-rich molecules like glucose.
• Cellular Respiration is the opposite
process extracting that stored energy from
glucose to for ATP.
• The chemical equation:
energy   ENERGY
C6H12O6 + 6O2  6CO2 + 6 H2O
Background Chemistry
• OXIDATION-REDUCTION reaction =
chemical reactions which involve a
partial or complete TRANSFER of
electrons from one reactant to
another. (REDOX reactions)
• OXIDATION = partial or complete
LOSS of electrons
• REDUCTION= a partial or complete
GAIN of electrons
Fig. 9-UN1
p164
becomes oxidized
(loses electron)
becomes reduced
(gains electron)
Fig. 9-UN2
becomes oxidized
becomes reduced
Fig. 9-3
p165
Reactants
Products
becomes oxidized
becomes reduced
Methane
(reducing
agent)
Oxygen
(oxidizing
agent)
Carbon dioxide
Water
**Cell Respiration LAB 5
• Practice Writing Lab Reports NEEDED!
• Tomorrow you will need to have your lab
notebook prepared with complete lab
format and data table ready to record
• Follow the ARHS Lab Format Guidelines
ALWAYS (blue form you should have
received in September/ more available)
• EXAMPLE on how to start: next slide
**EXAMPLE
Title: Cell Respiration
Purpose: (Read the full procedure; using the
Overview, Objectives, Introduction and noting our
discussion on previous slide--- write out in your own
words the Purpose of the Lab procedure; Sometimes
their will be need to make a prediction/hypothesis)
Please predict which temperature will have a higher
rate of cellular respiration. Cold or room temp??
Materials: “as on procedure sheet”
Procedure: “as on procedure sheet” is OK but it is
recommended to draw the procedural set up OR
flow chart the procedure
**Pre Lab Questions
Answer before DATA
• What is the purpose of the KOH in the
procedure?
• Why do we use Water Displacement when
setting up the tubes?
*****
• DATA:
(Draw in OR tape in the data table given to you
in the procedure) (There is a special table made
especially for that purpose)
Each lab group will be assigned a particular
temperature
Blue (stations 1, 2, 6) --- Cold Temp
[You will need ice]
Silver (stations 3, 4, 5) --- Room Temp.
Lab Debrief –
•
•
•
•
•
11/29/16
Record your group’s data average.
Determine the class average data.
What does the class data tell us?
Did the data support your hypothesis?
Note what needs to be included for lab
writeup!
– LAB Due Tuesday, 11/30/16
– What question could you ask to learn more about
Cellular Respiration? Design a lab???
Fig. 9-UN3
P164
11/29/16
Cellular Respiration
Loses electrons
becomes oxidized
becomes reduced
Gains electrons
Rate of Cellular Respiration
• What are ways that we could measure this
rate?
1. Product produced?
Carbon dioxide OR Water
2. Reactant used?
Glucose OR Oxygen
3. Energy produced?
how would we measure energy?
Video clip
• Cellular Respiration
• 2 PHASES
– Glycolysis (anaerobic) Fermentation
– Aerobic
• Acetyl CoA production
• Citric Acid Cycle (Krebs Cycle)
• Electron Transport Chain (ETC)
• Phosphorylation – ATP
Cell Resp - Video Clip
• What are the key players in this
process?
• Who does this process?
• What is the purpose of this process?
• What did we measure in our cell
respiration lab?
Carbon cycle - video clip
• What does the Law of Conservation
of Mass state?
• How are Carbon atoms conserved?
• How does cellular respiration aide in
this cycle?
• Could you have carbon atoms that
once were part of Einstein?
• 11/30/16
White Board Share
11/30/16
• Using your lab report (Analysis #14)
• Record on white board your scientific
question for a new lab studying Cellular
Respiration…
• Each student will present a very brief
explanation of what you are testing for in
your designed experiment
– If possible share your hypothesis as well
Electron Shuttle [NAD+]
p166
• Nicotinamide Adenine Dinucleotide
(NAD+): A dinucleotide that
functions as a coenzyme in the redox
reactions of metabolism
• Coenzyme: small non protein
organic molecule that is required for
certain enzymes to function
• Dinucleotide: molecules with two
nucleotides
Fig. 9-4
2 e– + 2 H+
2 e– + H+
NADH
H+
Dehydrogenase
p166
Reduction of NAD+
NAD+
+
+ H+
2[H]
Oxidation of NADH
Nicotinamide
(reduced form)
Nicotinamide
(oxidized form)
Fig. 9-5
p166
H2 + 1/2 O2
2H
(from food via NADH)
Controlled
release of
+
–
2H + 2e
energy for
synthesis of
ATP
1/
2 O2
Explosive
release of
heat and light
energy
1/
(a) Uncontrolled reaction
(b) Cellular respiration
2 O2
NAD+ in Cellular
Respiration
• During oxidation (loss of electrons)
of glucose, NAD+ functions as an
oxidizing agent by trapping energyrich electrons from glucose or food.
These reactions are catalyzed by
enzymes called DEHYDROGENASES,
which:
 Remove a pair of hydrogen atoms (2 eand 2p) from a substrate
 Deliver the 2e- and 1p to NAD+  NADH
 Release the remaining hydrogen proton
into the surrounding solutions  H+
Cellular Respiration
• These high energy electrons
transferred from substrate (H) to NAD+
are then passed down the ELECTRON
TRANSPORT CHAIN to oxygen,
powering the ATP SYNTHESIS
(oxidative phosporylation)
Cell Respiration Overview
• Respiration in the presence of oxygen is
called: aerobic respiration
• Aerobic respiration is divided into three
components:
– Glycolysis
– Krebs Cycle
– Chemiosmosis -- Electron Transport Chain
with Oxidative phosphorylation (oxidative
respiration)
Figure 9.6-3 p. 167
Electrons carried
via NADH and
FADH2
Electrons
carried
via NADH
Glycolysis
Glucose
Pyruvate
CYTOSOL
Pyruvate
oxidation
Acetyl CoA
Citric
acid
cycle
Oxidative
phosphorylation:
electron transport
and
chemiosmosis
MITOCHONDRION
ATP
ATP
ATP
Substrate-level
phosphorylation
Substrate-level
phosphorylation
Oxidative
phosphorylation
Fig. 9-7
p168
Enzyme
Enzyme
ADP
P
Substrate
+
Product
ATP
Glycolysis
• Glycolysis is the decomposition (lysis) of
glucose (glyco) to pyruvate.
• Catabolic pathway during which Glucose is
split into two 3-carbon sugars, which are then
oxidized and rearranged by a step-wise
process that produces pyruvate & ATP
• Follow the next few slides on pages 169
Specifics – “must know facts”
• Occurs in
Cytoplasm
• Catalyzed by
enzymes
• Occurs with or
without oxygen
• No CO2 is
released
Fig. 9-9-1
p169
Glucose
ATP
1
Hexokinase
ADP
Glucose
Glucose-6-phosphate
ATP
1
Hexokinase
ADP
Glucose-6-phosphate
Fig. 9-9-2
Glucose
ATP
1
Hexokinase
ADP
Glucose-6-phosphate
2
Phosphoglucoisomerase
Fructose-6-phosphate
Glucose-6-phosphate
2
Phosphoglucoisomerase
Fructose-6-phosphate
Fig. 9-9-3
Glucose
ATP
1
Hexokinase
ADP
Fructose-6-phosphate
Glucose-6-phosphate
2
Phosphoglucoisomerase
ATP
3
Phosphofructokinase
Fructose-6-phosphate
ATP
3
Phosphofructokinase
ADP
ADP
Fructose1, 6-bisphosphate
Fructose1, 6-bisphosphate
Fig. 9-9-4
Glucose
ATP
1
Hexokinase
ADP
Glucose-6-phosphate
2
Phosphoglucoisomerase
Fructose1, 6-bisphosphate
4
Fructose-6-phosphate
ATP
Aldolase
3
Phosphofructokinase
ADP
5
Isomerase
Fructose1, 6-bisphosphate
4
Aldolase
5
Isomerase
Dihydroxyacetone
phosphate
Dihydroxyacetone
phosphate
Glyceraldehyde3-phosphate
Glyceraldehyde3-phosphate
Fig. 9-9-5
2 NAD+
2 NADH
+ 2 H+
6
Triose phosphate
dehydrogenase
2 Pi
2 1, 3-Bisphosphoglycerate
Glyceraldehyde3-phosphate
2 NAD+
2 NADH
Energy
Payoff Phase
6
Triose phosphate
dehydrogenase
2 Pi
+ 2 H+
2 1, 3-Bisphosphoglycerate
Fig. 9-9-6
2 NAD+
2 NADH
+ 2 H+
6
Triose phosphate
dehydrogenase
2 Pi
2 1, 3-Bisphosphoglycerate
2 ADP
7
Phosphoglycerokinase
2 ATP
2 1, 3-Bisphosphoglycerate
2 ADP
2
3-Phosphoglycerate
2 ATP
2
7
Phosphoglycerokinase
3-Phosphoglycerate
Fig. 9-9-7
2 NAD+
2 NADH
+ 2 H+
6
Triose phosphate
dehydrogenase
2 Pi
2 1, 3-Bisphosphoglycerate
2 ADP
7 Phosphoglycerokinase
2 ATP
2
3-Phosphoglycerate
8
2
3-Phosphoglycerate
Phosphoglyceromutase
2
8
Phosphoglyceromutase
2-Phosphoglycerate
2
2-Phosphoglycerate
Fig. 9-9-8
2 NAD+
2 NADH
+ 2 H+
6
Triose phosphate
dehydrogenase
2 Pi
12/1/16
2 1, 3-Bisphosphoglycerate
2 ADP
7 Phosphoglycerokinase
2 ATP
2
3-Phosphoglycerate
2
2-Phosphoglycerate
8
Phosphoglyceromutase
9
2
2 H2O
2-Phosphoglycerate
Enolase
9
Enolase
2 H2O
2
Phosphoenolpyruvate
2
Phosphoenolpyruvate
Fig. 9-9-9
2 NAD+
6
Triose phosphate
dehydrogenase
2 Pi
2 NADH
+ 2 H+
2 1, 3-Bisphosphoglycerate
2 ADP
7 Phosphoglycerokinase
2 ATP
2
Phosphoenolpyruvate
2 ADP
2
3-Phosphoglycerate
8
Phosphoglyceromutase
2 ATP
2
10
Pyruvate
kinase
2-Phosphoglycerate
9
2 H2O
Enolase
2 Phosphoenolpyruvate
2 ADP
10
Pyruvate kinase
2 ATP
2
2
Pyruvate
Pyruvate
Fig. 9-8
Energy investment phase
p168
Glucose
2 ADP + 2 P
2 ATP
used
4 ATP
formed
Energy payoff phase
4 ADP + 4 P
2 NAD+ + 4 e– + 4 H+
2 NADH + 2 H+
2 Pyruvate + 2 H2O
Net
Glucose
4 ATP formed – 2 ATP used
2 NAD+ + 4 e– + 4 H+
2 Pyruvate + 2 H2O
2 ATP
2 NADH + 2 H+
Krebs Cycle
– IF Oxygen is Present…
• The Krebs cycle details what happens to the
pyruvate end product of glycolysis.
• Remember, 2 pyruvate enter the Krebs cycle,
so it is actually run twice for each molecule of
glucose.
• The steps are detailed next…
• Follow on page 170-171
Krebs Cycle
• Specifics:
1. Hans Krebs, German-British scientist,
1930s
2. Also known as Citric Acid Cycle
3. Process occurs in Mitochondria
Krebs Cycle / Citric Acid
Cycle
Part 1 (p 170)
Before going into cycle:
Pyruvate is converted to Acetyl CoA.
In a step leading up to the actual
Krebs cycle, pyruvate combines with
coenzyme A (CoA). In that reaction,
1 NADH and 1 CO2 are also
produced.
Fig. 9-10
p170
CYTOSOL
MITOCHONDRION
NAD+
NADH + H+
2
1
Pyruvate
Transport protein
3
CO2
Coenzyme A
Acetyl CoA
Krebs – part 2
• Krebs Cycle: 3 NADH, 1 FADH2 (another
electron carrier), 1 ATP, and 1 CO2
• The Krebs cycle begins when acetyl CoA
combines with OAA (oxaloacetic acid) to
form citric acid [citrate]. Along the way, 3
NADH and 1 FADH2 are made and CO2 is
released.
– Because the first product from acetyl CoA
is citric acid, Krebs is sometimes referred
to as the citric acid cycle.
– Let’s follow along pages 170-171
Fig. 9-11
Pyruvate
p170
CO2
NAD+
CoA
NADH
+ H+
Acetyl CoA
CoA
CoA
Citric
acid
cycle
FADH2
2 CO2
3 NAD+
3 NADH
FAD
+ 3 H+
ADP + P i
ATP
Fig. 9-12-1
p171
Acetyl CoA
CoA—SH
1
Oxaloacetate
Citrate
Citric
acid
cycle
Fig. 9-12-2
Acetyl CoA
CoA—SH
H2O
1
Oxaloacetate
2
Citrate
Isocitrate
Citric
acid
cycle
Fig. 9-12-3
Acetyl CoA
CoA—SH
1
H2O
Oxaloacetate
2
Citrate
Isocitrate
NAD+
Citric
acid
cycle
3
NADH
+ H+
CO2
-Ketoglutarate
Fig. 9-12-4
Acetyl CoA
CoA—SH
1
H2O
Oxaloacetate
2
Citrate
Isocitrate
NAD+
Citric
acid
cycle
NADH
+ H+
3
CO2
CoA—SH
-Ketoglutarate
4
NAD+
Succinyl
CoA
NADH
+ H+
CO2
Fig. 9-12-5
Acetyl CoA
CoA—SH
1
H2O
Oxaloacetate
2
Citrate
Isocitrate
NAD+
Citric
acid
cycle
NADH
+ H+
3
CO2
CoA—SH
-Ketoglutarate
4
CoA—SH
5
NAD+
Succinate
GTP GDP
ADP
ATP
Pi
Succinyl
CoA
NADH
+ H+
CO2
Fig. 9-12-6
Acetyl CoA
CoA—SH
H2O
1
Oxaloacetate
2
Citrate
Isocitrate
NAD+
Citric
acid
cycle
NADH
+ H+
3
CO2
Fumarate
CoA—SH
6
-Ketoglutarate
4
CoA—SH
5
FADH2
NAD+
FAD
Succinate
GTP GDP
ADP
ATP
Pi
Succinyl
CoA
NADH
+ H+
CO2
Fig. 9-12-7
Acetyl CoA
CoA—SH
H2O
1
Oxaloacetate
2
Malate
Citrate
Isocitrate
NAD+
Citric
acid
cycle
7
H2O
NADH
+ H+
3
CO2
Fumarate
CoA—SH
-Ketoglutarate
4
6
CoA—SH
5
FADH2
NAD+
FAD
Succinate
GTP GDP
ADP
ATP
Pi
Succinyl
CoA
NADH
+ H+
CO2
Fig. 9-12-8
Acetyl CoA
CoA—SH
NADH
+H+
H2O
1
NAD+
8
Oxaloacetate
2
Malate
Citrate
Isocitrate
NAD+
Citric
acid
cycle
7
H2O
NADH
+ H+
3
CO2
Fumarate
CoA—SH
6
-Ketoglutarate
4
CoA—SH
5
FADH2
NAD+
FAD
Succinate
GTP GDP
ADP
ATP
Pi
Succinyl
CoA
NADH
+ H+
CO2
Summary of Pathway
1. Pyruvate enters inner compartment of
mitochondrion
• Gives off CO2
• Converts NAD+ to NADH
2. Acetyl CoA is now a 2-carbon molecule
which enters the cycle by attaching to 4carbon oxaloacetate to form 6-carbon
citrate or citric acid
3. Each pyruvate or Acetyl CoA enters the
cycle, thus it occurs twice for every
Glucose molecule
4. As the cycle progresses:
•
•
•
•
•
2 CO2 produced as waste
3 NADH produced for ETC
1 FADH2 produced for ETC
1 ATP formed for ENERGY
Oxaloacetate reformed for cycle to repeat
SO… for each pyruvate --- yields
4 NADH; 1 FADH2; 1 ATP; 3 CO2
For each glucose???
Oxidative Phosporylation
• Oxidative phosphorylation is the process
of extracting ATP from NADH and FADH2.
• Electrons from NADH and FADH2 pass
along an ETC analogous to ETC chains in
photophosphorylation.
• These electrons pass from one protein
carrier to another along the chain, losing
energy along the way
• Follow with pages 172-175
Oxidative Phosporylation
• Cytochromes and various other modified
proteins act as carrier proteins in the chain.
• One cytochrome, cytochrome c, can be used
by geneticists to assess genetic relatedness
• The last electron acceptor at the end of the
chain is oxygen.
• The ½ O2 accepts the 2 electrons and, together
with H+ forms water.
• NADH provides electrons that have enough
energy to phosphorylate approximately 2.5 ADP
to 2.5 ATP.
• FADH2 produces approximately 1.5 ATP.
• Follow page 173-175
p173
ATP Synthase p174
• ATP Synthase is embedded in the
inner Mitochondrial membrane
• H+ gradiant is formed thanks to the
E.T.C.
• This energy of H+ movement (due to
concentration gradient) drives the
cylindrical rotor of the complex protein
• This spins in the knob – catalytic knob,
which allow the joining of inorganic
phosphate to ADP
• This is where ATP is produced
Fig. 9-14
INTERMEMBRANE SPACE
p174
H+
Stator
Rotor
Internal
rod
Catalytic
knob
ADP
+
P
i
ATP
MITOCHONDRIAL MATRIX
ETC + Chemiosmosis
• Coupled process – to ATP Synthesis
• ETC and pumping of protons (H+)
creates an H+ gradient across the
membrane
+
• Chemosmosis -- Powered by the flow of
H+ ions back across the membrane
• ONLY occurs because of the presences
of _____________ (final electron
acceptor)
Figure 9.15
p175
H
H
Intermembrane
space

H
Protein
complex
of electron
carriers
Cyt c
Q
I
IV
III
II
FADH2 FAD
NADH
H
2 H + 1/2O2
H2O
NAD
ADP  P i
(carrying electrons
from food)
Mitochondria
Matrix
ATP
synthase
ATP
H
1 Electron transport chain
Oxidative phosphorylation
2 Chemiosmosis
How Many ATP?
How many ATP are made from the energy
released from the breakdown of 1 glucose
molecule?
–
–
–
–
Glycolysis = 2 ATP and 2 NADH
Pyruvate conversion = 2 NADH
Acetyl CoA/Krebs = 6 NADH, 2FADH2, 2 ATP
Oxidative phosphorylation = NADH produces 2.5 ATP
each & FADH2 produces 1.5 ATP each (total = 28
ATP)
Total ~ ~32 ATP (estimated number) per glucose molecule
Figure 9.16
Electron shuttles
span membrane
2 NADH
Glycolysis
2 Pyruvate
Glucose
MITOCHONDRION
2 NADH
or
2 FADH2
2 NADH
Pyruvate oxidation
2 Acetyl CoA
 2 ATP
Maximum per glucose:
CYTOSOL
6 NADH
2 FADH2
Citric
acid
cycle
Oxidative
phosphorylation:
electron transport
and
chemiosmosis
 2 ATP
 about 26 or 28 ATP
About
30 or 32 ATP
Mitochondria
• The Krebs cycle and the conversion of
pyruvate to acetyl CoA occur in the
mitochondrial matrix (the fluid portion)
• The ETC proteins are embedded in the
cristae (inner folded membrane)
• The cristae separate the mitochondrion into
an inner compartment with matrix and an
outer compartment between the cristae and
outer membrane.
Intermembrane
Space
Chemiosmotic Theory
• Electrons from NADH and FADH2 lose energy
as they pass along the ETC in oxidative
phosphorylation.
• That energy is used to phosphorylate ADP to
ATP.
• Chemiosmotic theory describes how that
phosphorylation occurs.
• The process is analogous to ATP generation in
chloroplasts for Photosynthesis
Anaerobic Fermentation
• What if oxygen is not present?
• If oxygen is not present, there is no final
electron acceptor for the ETC.
• If this occurs, then NADH accumulates.
Once all the NAD+ has been converted to
NADH, the Krebs cycle and glycolysis both
stop (both need NAD+ to accept
electrons).
• Once this happens, no new ATP is
produced and the cell dies.
Anaerobic Fermentation
• Anaerobic respiration (fermentation) is a
method cells use to avoid death due to the
lack of O2.
– Alcoholic Fermentation
– Lactate Fermentation
Fig. 9-19
Glucose
p179
Glycolysis
CYTOSOL
Pyruvate
No O2 present:
Fermentation
O2 present:
Aerobic cellular
respiration
MITOCHONDRION
Ethanol
or
lactate
Acetyl CoA
Citric
acid
cycle
Alcoholic Fermentation
(p163)
• Alcoholic fermentation (or just “fermentation”) occurs
in plants, fungi, (yeast), and bacteria. The steps are
as follows:
• 1. pyruvate to acetaldehyde. For each pyruvate,
1 CO2 and 1 acetaldehyde are produced. The CO2
formed is the source of carbonation in fermented
drinks.
• 2. Acetaldehyde to ethanol. The important part of
this step is that the energy in NADH is used to drive
this reaction, releasing NAD+. Remember NAD+ is
needed to run respiration. For each acetaldehyde, 1
ethanol is made and 1 NAD+ is produced.
Fig. 9-18a
p178
2 ADP + 2 P i
Glucose
2 ATP
Glycolysis
2 Pyruvate
2 NAD+
2 Ethanol
(a) Alcohol fermentation
2 NADH
+ 2 H+
2 CO2
2 Acetaldehyde
Alcoholic Fermentation
• WHY? The goal of this pathway is the task
of freeing NAD+ to allow glycolysis to
continue.
• Recall that in the absence of O2, all the
NAD+ is bottled up in NADH.
• The purpose of the fermentation pathway is
to release some NAD+ for use by glycolysis.
• The reward for this effort is only 2 ATP. Not
much, but better than cell death.
Lactate Fermentation
(p163)
• There is only one step in lactate fermentation. A
pyruvate is converted into lactate (or lactic acid),
and in the process, NADH gives up its electrons
to form NAD+.
• As in alcoholic fermentation, the NAD+ can now
be used for glycolysis. When O2 becomes
available, lactate can be broken down.
• Because O2 is required to break down lactate,
lactate fermentation creates an oxygen debt.
Fig. 9-18b
p178
2 ADP + 2 P i
Glucose
2 ATP
Glycolysis
2 NAD+
2 NADH
+ 2 H+
2 Pyruvate
2 Lactate
(b) Lactic acid fermentation
Metabolic Pathway
1/2/16
• Do other biomolecules besides
Glucose go through Cellular
Respiration?
• Note p 180
Fig. 9-20
Proteins
Carbohydrates
Amino
acids
Sugars
Glycolysis
Glucose
Glyceraldehyde-3- P
NH3
Pyruvate
Acetyl CoA
Citric
acid
cycle
Oxidative
phosphorylation
Fats
Glycerol
Fatty
acids
Control of Cellular Respiration
(p181)
• Feedback mechanisms control C.R.
• Big Players are
1) ATP presence / concentration
2) Citrate presence/ concentration
3) AMP Presence / concentration
• This mechanisms controls balance of
a cell’s catabolic and anabolic
reactions
Fig. 9-21
Glucose
AMP
p181
Glycolysis
Fructose-6-phosphate
–
Stimulates
+
Phosphofructokinase
–
Fructose-1,6-bisphosphate
Inhibits
Inhibits
Pyruvate
ATP
Citrate
Acetyl CoA
Citric
acid
cycle
Oxidative
phosphorylation