Oxygen accumulation in the primitive atmosphere occured...WHEN?
after cyanobacteria evolved and were capable of non-cyclic photosynthesis
In eukaryotic cells, aerobic respiration takes place in the _______.
MITOCHONDRIA
T OR F ?
MITOCHONDRIA ARE Prominent in photosynthetic and non-photosynthetic plant cells?
TRUE
T OR F ?
MITOCHONDRIA MAKE UP 15 to 20% of mammalian liver cell volume?
TRUE
Often associated with food stores such as lipid droplets.
MITOCHONDRIA
Large organelles, often reticulated and osmotically active structures
MITOCHONDRIA
WHAT IS A MITCHONDRIA COMPOSED OF?
An outer porous membrane
Porosity from integral membrane proteins
Porins made of b sheets in barrel formation
Highly impermeable inner membrane
Thrown into folds called cristae
Contain much of the machinery required for aerobic respiration
Porins made of WHAT?
b sheets in barrel formation
Contain much of the machinery required for aerobic respiration
folds called cristae OF THE MITOCHONDRIA
WHERE DOES ONE FIND THE PEPTIDOGLYCAN IN A MITOCHONDRIA?
MIDDLE OF THE MEMBRANE.
T OR F?
MITOCHONDRIA ARE TYPICALLY BACTERIAL IN SIZE
TRUE.
MITOCHONDRIA....Outer and inner membranes enclose two spaces, NAME THEM
:The matrix and intermembrane space.
MITOCHONDRIA....Difference between the inner and outer membrane...NAME 4
1. Outer has less than 50% protein, inner membrane is more than 75% protein.
2. The inner membrane contains cardiolipan but not cholesterol (same for bacteria).
3. The inner membrane is impermeable to even small molecules and ions
4. Outer membrane is permeable to proteins
MITOCHONDRIA....
Outer has less than ____% protein,
inner membrane is more than ______% protein
OUTER.....LESS THAN 50%
INNER.....MORE THAN 75%
Mitochondrial membranes.
The inner membrane contains ______ but not ________(same for bacteria)
cardiolipan
cholesterol
The Mitochondrial Matrix contains serveral enzymes and accessory proteins. HOW MUCH??
500 mg/ml.
NAME 9 PARTS
MITOCHONDRIA.
DNA?
RNA?
RIBSOMES ?
DNA: CIRCULAR molecule; nonchromosomal
RNA: 22 tRNAs
Ribosomes (70s)
HOW DO MITOCHONDRIA REPLICATE?
self replicate by binary fission and can fuse together
T OR F? RIBOSOMES AND ENZYMES OF THE MITOCHONDRIA CAN BE CONSTRUCTED WHERE?
IN THE MATRIX
Converts the products from carbohydrate, fat, and protein catabolism into chemical energy.
WHAT IS THIS KNOWN AS AND WHERED DOES IT OCCUR?
oxidative metabolism.
mitochondria is the center of oxidative metabolism
The mitochondria is the center of oxidative metabolism.
ATP IS FORMED THRU WHAT PROCESS?
oxidative phosphorylation
Glycolysis produces_______,________&_______ via _______ ________ ________.
pyruvate,
NADH,
2 ATP
via substrate level phosphorylation
GLYCOLYSIS WITHOUT O2...WHAT HAPPENS TO NADH AND ATP ?
NADH is recycled without ATP production
ATP is limited to this amount/glucose molecule via SLP
Cellular respiration is therefore a process in which ......
the energy in glucose is transferred to ATP.
GLYCOLYSIS OCCURS WHERE IN THE CELL?
TCA OCCURS WHERE IN THE CELL?
Aerobic organisms use molecular oxygen to extract more than _____ more ATP from pyruvate and NADH
30
__________ is transported across the inner membrane of the mitochondria
Pyruvate
___________ is Decarboxyated to form acetyl CoA
PYRUVATE
tricarboxylic acid cycle (TCA)....ALSO KNOWN AS WHAT?
KREBS CYCLE
(elucidated in 1930s)
English jounal Nature rejected manuscript as not important enough for publication
JUST INSIDE THE MITOCHONDRIA, PYRUVATE AND NAD+ ---> ??? THEN WHAT HAPPENS?
NADH AND ACETYL CoA....THAT GO INTO THE TCA CYCLE
The glycerol phosphate shuttle. WHERE IS THE NAD & FAD IN THIS PROCESS.
NAD OUTSIDE
FAD CYTOSOL
NADH formed during glycolysis enters the mitochondria via _________ OR __________ METHODS.
malate-aspartate or glycerol phosphate shuttles
Reduced coenzymes are important for the formation of ATP.
NAME THEM
FADH2 and NADH are primary products of the TCA cycle
Cytosolic NADH to Inner membrane FADH2.
HOW?
_______ PAIRS OF e- (FROM HYDROGEN ATOMS OF SUBSTRAIT) ARE USED IN ATP PRODUCTION DURING TCA. WHERE DO THEY COME FROM?
5
NADH
FADH2
Four reactions IN TCA CYCLE transfer a pair of electrons to oxidizing/reducing couples:
NAD+ to form NADH
FAD+ to form FADH2
NAME THE STEPS WHEN THIS OCCURS
1. ISOCIRTRATE TO KETOGLUTARATE (NAD)
2. KETOGLUARATE TO SUCCINYL-CoA (NAD)
3. SUCCINATE TO FUMARATE (FAD) 4. MALATE TO OXALOACETATE (NAD)
NOTE: PYRUVATE/NAD B4 TCA CYCLE.
TCA MEANS WHAT?
Tricarboxylic Acid Cycle
As electrons move through the electron transport chain, ___ are pumped out across the inner membrane
H+
Energy is released and used to create an electrochemical gradient
Electrons pass from FADH2 or NADH to O2, the terminal electron acceptor...WHAT IS THE FORMULA AND WHERE DOES IT OCCUR?
NADH + 1/2 O2 + H+ => H2O + NAD+
Occurs through the chain of electron carriers in the inner membrane
THE TERMINAL ELECTRON ACCEPTOR IN THE ETS IS WHAT?
O2
Electrons pass from FADH2 or NADH to O2, the terminal electron acceptor.NADH + 1/2 O2 + H+ => H2O + NAD+
WHERE FOES THE ELECTRON TRANSPORT SYSTEM OCCUR?
Occurs through the chain of electron carriers in the inner membrane.
The coupling of H+ translocation to ATP synthesis is called ___________.
chemiosmosis
THE MOVEMENT OF THE H+ FROM THE INNER MEMBRANE TO THE MATRIX OCCURS AT WHAT SITE?
ATP synthesizing enzyme, ATP synthase.
Formation of ATP occurs at the enzymes catalytic site.
Chemiosmotic Hypothesis. Was first verbalized by WHO AND WHEN ?
Peter Mitchell in 1961
____ molecules of ______ are formed from each pair of electrons donated by NADH + H+
3 ATP
each pair of electrons donated by NADH + H+ WILL YEILD HOW MANY ATP?
Three molecules of ATP are formed from each pair of electrons donated by NADH + H+
_______ molecules of ____ are formed for each pair of electrons donated by FADH2
2 ATP
for each pair of electrons donated by FADH2...HOW MANY ATP?
Two molecules of ATP are formed for each pair of electrons donated by FADH2
BESIDES THE ETC, ATP is also synthesized at the substrate level in the ______ ________ & ________ _______.
glycolytic pathway and the Krebs cycle
Substrate Level- ATP made directly from________ OR _______. HOW MANY PER METHOD?
Glycolysis(2)
Krebs Cycle(2).
Oxidative Level- ATP made from ______ & _______.
WHERE DOES THIS OCCUR AND HOW MANY ATP MADE?
NADH or FADH2 in the ETC.
32 ATP
Stepwise cycle where substrate is oxidized and its energy conserved.
Tricarboxylic Acid Cycle
The two carbon ________ is condensed with 4 carbon _________. Forms 6 carbon ________. AND THUS NAME _______ ______ _______.
2C acetyl CoA
4C oxaloacetate
6C Citrate
Citric acid cycle
During the cycle, HOW MANY C ARE OXIDIZED INTO CO2? WHAT ARE THEY USED FOR?
2C.
Regenerates the 4 carbon oxaloacetate needed to continue the cycle.
Each carrier in the electron transport chain are arranged in order of ______ _____ ______.
increasing redox potential.
NAD+ + 2H+ + 2e- ------> ??
NADH + H+
NADP+ + 2H+ + 2e- ------> ??
NADPH + H+
There are 4 types of redox (ELECTRON) carriers. NAME THEM.
•Flavoproteins: are polypeptides bound to either FAD or FMN
•Cytochromes: contain heme groups: Fe or Cu metal ions
•Ubiquinone:(coenzyme Q) is a lipid-soluble molecule.Made of five carbon isoprenoid units.
•Iron sulfur proteins: contain Fe in association with inorganic sulfur rather than heme.
_______ are polypeptides bound to either FAD or FMN.
ALSO...WHAT TYPE OF ELECTRON CARRIER?
Flavoproteins.
redox carriers (1 OF 4)
________ contain heme groups. Fe or Cu metal ions.
ALSO WHAT TYPE OF CARRIER?
Cytochromes.
REDOX CARRIER (1 OF 4)
________ AKA _______ is a lipid-soluble molecule.
Made of five carbon isoprenoid units.
ALSO, WHAT TYPE OF CARRIER?
Ubiquinone (coenzyme Q)
REDOX CARRIER (1 OF 4)
____ _______ _______ contain Fe in association with inorganic sulfur rather than heme.
ALSO, WHAT TYPE OF CARRIER?
Iron sulfur proteins.
REDOX CARRIER (1 OF 4)
NAME 2 mobile carriers.
Cytochrome c and ubiquinone
(shuttle electrons)
HOW ARE CYTOCHROMES AND CYTOCHROME C DIFFERENT?
Cytochromes is a redox carrier. Contain heme groups. Fe or Cu metal ions.
Cytochrome c is a mobile carriers (shuttle electrons)
Four Electron Transport Complexes.
NAME THEM.
Complex I: NADH dehydrogenase.
Complex II: Succinate dehydrogenase.
Complex III: Cytochrome bc1.
Complex IV: Cytochorme c oxidase.
DEFINE ETC COMPLEX I
NADH dehydrogenase:
Catalyzes transfer of electrons from NADH to ubiquinone and transports 4 H+ per pair
DEFINE ETC COMPLEX II
Succinate dehydrogenase:
Catalyzes the transfer of electrons from succinate to FAD to ubiquinone with no transport of H+
DEFINE ETC COMPLEX III
Cytochrome bc1:
Catalyzes the transfer of electrons from ubiquinone to cytochrome c and transports 4 H+ per pair
DEFINE ETC COMPLEX IV
Cytochorme c oxidase:
Catalyzes transfer of electrons to O2 and transports H+ across the inner membraneForms water while removing protons
IN WHAT ETCCOMPLEX IS WATER FORMED WHILE REMOVING PROTONS?
Complex IV:
Cytochorme c oxidase:
Catalyzes transfer of electrons to O2 and transports H+ across the inner membrane.
Forms water while removing protons.
WHAT ARE THE SIZES OF THE 4 ELECTRON TRANSPORT COMPLEXES?
OF THE 4 COMPLEXES, WITCH ONE DEALS WITH SUCCINATE?
HOW MANY H+ DOES IT PUMP INTO THE INTERMEMBRANE SPACE?
COMPLEX II
DOESN'T PUMP H+ OUT. (ONLY ONE)
OF THE 4 COMPLEXES, WHICH IS THE LARGEST?
HOW MANY H+ DOES IT PUMP INTO THE INTERMEMBRANE SPACE?
COMPLEX I
4 H+
WHAT WOULD BE A MAIN DIFFERENCE BTWN CYTOCHROME bc1 (COMPLEX III) AND CYTOCHROME c OXIDASE?
BESIDES THE OXIDASE!
CYTOCHROME bc1 (COMPLEX III) RECIEVES UQ FROM COMPLEXES I AND II
WHAT IS THE MOLECULAR MASS COMPLEX IV?
HOW MANY H+ DOES IT PUMP INTO THE INTERMEMBRANE SPACE?
ABOUT 200,000
2H+
WHAT IS THE SIZE OF COMPLEX III?
HOW MANY H+ DOES IT PUMP INTO THE INTERMEMBRANE SPACE?
MOLECULAR MASS (Da) ABOUT 240,000.
4 H+
Mechanism of action of cytochrome oxidase (COMPLEX IV).
WHAT IS THE FLOW OF e-?
4e- centers. Fe= red Cu = YLW.CO, Azide, and cyanide all bind heme of cyta3.
There are two components to the proton gradient..NAME THEM
pH gradient (DELTA pH)The concentration difference between the matrix and intermembrane space.
electric potential gradient (TRIDENT SYMBOL)The voltage difference resulting from the separation of charge across the membrane.
pH gradient (DELTA pH) + electric potential gradient (Y) =?
Protonmotive Force
80% is due to voltage,
20% due to the proton gradient
Increases H+ permeability through membrane.
ATP synthase no longer only way back to low side of H+ gradient.
WHAT IS IT?
Dinitrophenol
WHAT IS Dinitrophenol?
uncouples glucose oxidation and ATP formation.
Increases H+ permeability through membrane.
ATP synthase no longer only way back to low side of H+ gradient
Visualization of proton-motive force...WHAT DO YOU USE?
fluorescent cationic JC-1
Visualization of proton-motive force...HOW DOES IT WORK?
Use of fluorescent cationic JC-1
Active cells generate voltage gradient
Leads to accumulation of lipid soluble substance in mitochondria (negative inside)
Orange areas have high membrane potential, green = low.
Catalyzes the formation of ATP
ATP SYNTHASE
ATP synthase NAME THE PARTS.
F1 head projects into the matrix and includes the catalytic sites
Fo base is embedded in the lipid bilayer. Forms the channel which protons are conducted from the intermembrane space into the matrix
ATP SYNTHASE.
_______ projects into the matrix and includes the catalytic sites
F1 HEAD
ATP SYNTHASE
________ is embedded in the lipid bilayer.
Forms the channel which protons are conducted from the intermembrane space into the matrix
Fo BASE
Machinery for ATP synthesis
WHO
WHEN
ON WHAT?
Fernandez-Moran, 1964 BEEF HEART
ATP SYNTHASE...WHERE IS THE C RING?
INTERMEMBRANE SPACE. 14 UNITS
C RING. HOW WAS THIS PIC TAKEN?
ATOMIC FORCE MICROSCOPY
ATP formation using submitochondrial particles.
HOW DO YOU BREAK IT APART AND WHAT ARE THE RESULTS.
SONICATION. JUST REMEMBER THAT ONCE YOU ADD UREA TO THE OXIDIZED SUBSTRANTES, NO MORE ATP.
DEFINE binding-change hypothesis
Movement of protons through the ATP synthase alters the binding affinity of the active site for ADP and Pi and ATP.
E IS REQUIRED.
IN BOUND STATE Pi TO ADP IS SPONTANEOUS.
ATP is synthesized through rotational catalysis
ATP is synthesized through rotational catalysis..HOW DOES IT WORK? WHAT MOVES?
THE ATP SYNTHASE STALK OF SYNTHASE ROTATES RELATIVE TO THE HEAD AND DRIVEN BY DOWNHILL MOVEMENT OF H+
Binding Change mechanism of ATP synthesis. NAME THEM
Open, Loose, Tight Conformations
Direct observation of rotational catalysis.
ACTIN FILLMANT SPINS WHAT WAY?
ATTACHED TO WHAT AND HOW?
Major Activities during aerobic respiration
ALL THE NADH FROM _______ GOTO WHAT COMPLEX?
TCA CYCLE
COMPLEX I
WHAT AMINO ACID IS IN THE RING OF THE C SUBUNITS?
Asp 61 "ASPARTIC ACID"
FROM THE INNER MEMBRANE TO THE MATRIX WHAT IS THE FLOW OF H+ THRU THE ATP SYNTHASE?
MATRIX IS ON TOP
ONE WAY OF IMPORTING MITOCHONDIAL PROTEINS IS Post-translationally transported.
HOW IS THIS DONE?
Synthesized in the cytosol and imported into the organelle.
THE 2 WAYS OF IMPORTING MITOCHONDRIAL PROTEINS
Encoded by the mitochondrial DNA.Synthesized in the organelle.
Synthesized in the cytosol and imported into the organelle
(Post-translationally transported)
Post-translationally transported PROTEINS NAME THE STEPS
DEFINE PORT TRANSLATION PROTEINS OF THE MITOCHONDRIA.
-Synthesized in the cytosol and contain positive charged targeting sequence.
-At the N-terminus end of peptide.
-Cause a polypeptide to bind to a receptor on outer mitochondrial surface.
This leads to the transport of the polypeptide into the matrix.
Process is powered by the voltage gradient.
-Import is aided by chaperones on both sides of the mitochondrial matrix.
Which cell type is likely to have the most mitochondria?
C. slow-twitch muscle
Which of the following are reduced coenzymes?
D. NADH and FADH2
Which of the following is not a feature of oxidative phosphorylation?
D. a protonmotive force
B. direct transfer of phosphate from a substrate molecule to ADP
_______ __________ is a metabolic pathway that uses energy released by the oxidation of nutrients to produce adenosine triphosphate (ATP).
Oxidative phosphorylation (or OXPHOS in short)
Why do some redox reactions in cells result in the transfer of electrons from a reductant with a higher standard redox potential to an oxidant with a lower standard redox potential?
Redox potentials are defined under standard conditions, and cellular conditions are typically not standard conditions.
In glycolysis, ATP is formed by the transfer of a high energy phosphate from 1,3-bisphosphoglycerate to ADP. No such high energy phosphate donor has ever been isolated in mitochondria. Why not?
No such phosphate donor exists
Using differential centrifugation, you are trying to isolate peroxisomes and glyoxysomes from a mixture of cellular organelles. After a few centrifugation steps, you think you may have a relatively pure suspension. How might you determine that your suspension does, indeed, have these organelles?
Do an assay for the enzyme catalase.
Which of the following experimental results does not support Mitchell's chemiosmosis theory?
A. Addition of dinitrophenol to isolated mitochondria was shown to inhibit electron transport, but had no effect on ATP synthesis.