12-3 Etc And Ox-Phos Turco

Front 1

Where is ETC at?

Back 1

On inner mitochondrial membrane

Front 2

What are some key coenzymes involved?

Back 2

pyridine: NAD
flavin: FAD FMN
coenzyme Q (CoQ10)/ubiquinone
Iron-containing proteins like cytochromes (heme) and FeS clusters

Front 3

The final products of this all are CO2 and H20. Why?

Back 3

CO2 is where the carbons went.
H20 is where the electrons went.

Front 4

NAD is the main entry to ETC. What all gives their electrons to NAD?

Back 4

Pyr
aKG
Isocitrate
Malate
Others

Front 5

What are the so-called bypass enzymes?

Back 5

Glycerol 3 P, succinate and Beta-ox of FA
They give their electrons to FAD which bypasses the main NAD and FMN. After that they're in the pathway the same.

Front 6

For every pair of e- you use ___

Back 6

1/2 O2 to go to H20

Front 7

What's an interesting difference about the enzymes that use NAD compared to FAD/FMN?

Back 7

NAD is reversibly associated with the enzymes. FAD/FMN will be tightly or covalently linked to enzymes.

Front 8

The ___ of Fe will ___ as electrons flow through the FeS centers. By how much?

Back 8

valency will reciprocate: Fe3+ <--> Fe 2+

Front 9

Coenzyme Q: is the only ETC component not associated with ___

How many electrons can it carry? What's it called?

Back 9

protein.

2. QH2 when carrying two. H+ don't matter, but are there.

Front 10

Cytochromes are ETC proteins that contain a ____. The various cytochromes are distinguished by their respective ___ ___ ___.

They're named:

Back 10

heme
light absorption spectra

a b and c

Front 11

The respiratory chain can be divided into discrete enzyme complexes with each having its own special carriers. How many and what

There are also two mobile carriers.

Back 11

Complex I: NAD -> FMN
Complex II: FAD/FeS
Mobile carrier Q
Complex III: cyt b/FeS -> cyt c1
Mobile carrier cyt c
Complex IV: Cyt aa3

Front 12

The protons being sent through the membrane the ETC is embedded in are going where?

Back 12

The intermembrane space. All the electron donators are in the matrix of the mitochondria.

Front 13

What is the enzyme involved in both Kreb's cycle and ETC?

Back 13

succinate DH
Succinate -- succinate DH--> fumarate

Front 14

If you blocked/ruined a complex, everything upstream would be fully ____ and everything after the block would be ___.

Back 14

Reduced and oxidized

Front 15

How do barbituates or ____ (the plant toxin insecticide) work?

Back 15

rotenone

They inhibit complex I so electrons can't go from NADH to oxygen. The bypass ones aren't enough.

Front 16

How does cyanide poison you? What else does this?

Back 16

CN- binds to Fe3+ in Complex IV (channel that CN can fit through) ---> electrons can't flow

CO binds to Fe2+ so in heme in Hb and also in ETC.

Front 17

What is ferric Fe? What's the other one?

Back 17

3+. Ferrous is 2+.

Front 18

What are symptoms of cyanide poisoning?

What's another way to get CN poisoning?

Back 18

Almond odor

Nitroprusside a hypertension drug -> OD and get CN poisoning

Front 19

How do you treat cyanide poisoning?

Back 19

amyl nitrite. An oxidizing agent that takes normal HbFe2+ and make it ferric, so CN binds Hb instead of ETC.

CN_ and thiosulfate ---> SCN- (thiocyanate) this is less toxic

Vitamin B12

Front 20

How many ATP does mito NADH make? FADH2?

How efficient is it?

Back 20

3. 2.

Very. Half the energy released is captured. The rest is released as heat.

Front 21

Describe that ATP synthase.

Back 21

F0 channel for protons. F1 component: ATP synthase aka elementary body.

Front 22

What gradients play a role in ATP synthase? What do you call it?

Back 22

Chemical gradient [H] and electrical gradient [H+], so the chemical concentration (pH in this case) and electrical potential difference together made the "proton motive force". This is where all the energy we've been getting out of the food goes.

Front 23

How did we get a proton gradient?

Back 23

The ETC kicks H+ into the intermembrane space while handing off the electrons.
So Q --2e--> QH2 has protons, but when hands off
Fe3+S--e--> Fe2+S + H+ ... FeS didn't want the proton.

Front 24

So what is our end game: we couple what two things?

Back 24

oxidative ETC and phosphorylation ADP->ATP aka oxidative phosphorylation

Front 25

Because the inner mito membrane is impermeable what problem arises that necessitates transporters?

Describe the transporters.

Back 25

All the ATP you're making needs to leave, and you need more ADP and Pi to put together

You have an adenosine nucleotide translocase which antiports ADP and ATP (favorable since intermembrane is positive and ATP is more negative)

Phosphate translocase symports a H+ with H2PO4 into the matrix.

Front 26

What regulates the ETC?

What's this called?

Back 26

ADP: the electrons won't flow through the chain to O2 unless there's ADP being phosphorylated to ATP.

Respiratory control.

Front 27

What's an example of an inhibitor at the ATP synthase stage?

Back 27

Oligomycin aka macrolide which blocks H+ trying to go into F0 channel. This makes cytoplasmic pH drop and e- flow stops.

Front 28

___ are molecules which dissociate the respiratory chain from phosphorylation.

An example.

Back 28

Uncouplers

Dinitrophenol. Destroys gradient by shuttling H+ back into the matrix. e- will flow in ETC, but can't drive ATP synthase this way, so no ATP.

Front 29

What was the drug experiment using oxidative phosphorylation as an obesity treatment?

Back 29

Gave them dinitrophenol since it uncouples- you'd spin your wheels putting e- through, but not make ATP- lose weight fast. Pts got hyperthermia since 100% of energy given off as heat.

Also see hyperventilation since increased O2 demands.

Front 30

What is brown fat?
Why is it brown?
Where is it located?
What is the special protein it has?

Back 30

Newborns have special adipose tissue to fuel oxidation just for heat. It looks dark because there are many mitochondria (and their cytochromes) among the adipose.
Back on the neck on infants.
thermogenin is the uncoupling protein: channel that lets H+ go back in matrix.

Front 31

Where does creatine p have its biggest role?

Back 31

In muscle and brain which have high E demands.

Front 32

What does creatine do for us? How?

Back 32

Acts as a reserve of high energy P.
In times of plenty, creatine kinase adds P to creatine. Then in working tissues, when ATP is used, Creatine-P + ADP -- creatine kinase--> Cr + ATP

Front 33

Creatine kinase has different isoforms and we use them diagnostically. Tell me more.

What's another diagnostic marker for this condition?

Back 33

MM isoform in muscle. BB in brain. MM and MB in heart.

In ischemic conditions (by definition you are not getting O2) -> no atp -> no pumps -> Ca goes wherever (also with water) ->phospholipases activated -> degrade lipids -> mito membrane leaking every where -> stuff damages cell -> plasma membrane leaking now-> see MB isoform if it was a heart attack.

troponin- lasts longer 5 vs 2 days.

Front 34

How does creatinine form?
What can it tell you in tests?

Back 34

The phosphate on creatine P is reactive and will go after itself making a ring.
Because it's formed and secreted at a constant rate, you can use it as a normalization factor during urine analysis.

Front 35

Describe a short sprint
muscle [ATP]
muscle [Cr-P]
And explain the energy sources

Back 35

In sprint, ATP levels go 5 -> 4mM, but Cr-P drop.

2 ADP -> AMP and ATP (this is the AMP for PFK1 and glycogen phophorylase)
Cr-P +ADP -> ATP
anaerobic glycolysis --> 2 ATP

keep ATP from dropping, but builds up lactate and lowers pH, so rate is not sustainable.

Front 36

Compare energy sources of a short sprint, medium run, and marathon

Back 36

Short sprint: short term suppliers work and anaerobic glycolysis
Medium run: uses oxidative phosphorylation
Marathon: Have to use aerobic pathways and FA oxidation products after glycogen is gone.