Koc - Ox Phos

Question 1

What are electron carriers for Complex I and Complex II?

Answer 1

FMN , FAD

Question 2

What is the only complex in OxPhos not mitochondrial coded?

Answer 2

Complex II

Question 3

Cytochromes

Answer 3

One elctron carriers

Iron coordinating rings

Mitochondrial coded

Question 4

Iron-Sulfur Clusters

Answer 4

Non mobile electron intermediate carriers within the Complexes

sort of like buckets for the fire brigade to pass water

Question 5

Ubiquinone or “CoenzymeQ” , “CoQ10”

Answer 5

Mobile electron carrier

Freely diffusible within the lipid bilayer

Complex II - Complex III

Question 6

Rieske Iron Sulfure Protein

Answer 6

Non-heme iron protein in complex III

Question 7

Complex I

Answer 7

NADH:Ubiquinone Oxidoreductase

Transfer two electrons from NADH to Ubiquinone

Four protons sent to intermembrane space

Question 8

Complex II

Answer 8

Succinate Dehydrogenase

Same enzyme form Kreb’s cycle (Succinate - Fumarate)

Electrons from FADH_2,, sent to Ubiquinone

Question 9

Complex III

Answer 9

Ubquinone:Cytochrome C Oxidoreductase

QH₂ gives two electrons to Cytochrom C

Four Protons pumped

Question 10

When does Cytochrome begin acting as mobile transport in ETC?

Answer 10

After III, Cytochrome C

Question 11

Cytochrome C

Answer 11

Mobile electron carrier

Moves through intermembrane space

Heme protein

Carry 1 electron

Question 12

Complex IV

Answer 12

Cytochrome Oxidase

O₂ reduced to 2H₂O

Four protons transported to intermembrane space

Question 13

Protons per molecule NADH?

What complexes does this pass flow through?

Answer 13

10 H⁺

Complex I - Complex IV

Question 14

Protones per molecule FADH₂

What complexes does this pass through?

Answer 14

6 protons

Complex II - Complex IV

(skips complex I)

Question 15

What is there “3-5” ATP made from the NADH from glycolysis?

Answer 15

The NADH must be transported from the cytoplasm, and one of these methods inserts it at Complex II, so less protons are pumped at the end.

Question 16

Malate-Aspartate Shuttle

Answer 16

Full complex chain

2.5 ATP / NADPH

(2x NADPH from glycolysis, 5 ATP total)

Question 17

Glycerol 3 Phosphate Shuttle

Answer 17

Enters at complex II

1.5 ATP / FADH₂

3 ATP total

Question 18

Where is the Malate-Aspartate Shuttle predominantly found?

Answer 18

Liver, Kidney, Hear

No energy lost

Question 19

What systems use the Glycerol 3-Phosphate Shuttle?

Answer 19

Skeletal Muscle and Brain

“Where is glycolysis prevalent?”

Question 20

Comple I Inhibitors

Answer 20

Amytal, Rotenone

Question 21

Complex III Inhibitors

Answer 21

Antimycin A

Question 22

Complex IV Inhibitors

Answer 22

Cyanide, Carbon Monoxide, Hydrogen Sulfide, Sodium Azide

Question 23

ATP Synthase Inhibitor

Answer 23

Oligomycin

Question 24

Uncoupling Agents

Example?

Answer 24

Break proton gradient

Dinitrophenol

Aspirin (high doses)

Question 25

Addition of Cyanide to mitochondria? ATP and O2 effect?

Answer 25

Complex IV inhibited O₂ not consumed ATP not generated

Question 26

Addition of DNP to mitochondria? Effect on ATP and O2?

Answer 26

Uncoupling agens--proton gradient broke O₂ - Still consumed, Complex IV can still run ATP - Not produced, no protons to spin ATP Synthase

Question 27

ATP Synthase F1 / Fo? Protons/ATP?

Answer 27

F1: Makes ADP in Matrix Fo: Transports protons, spins 4 Protons / ATP

Question 28

ATP Synthase Inhibitory Protein (IF1)

Answer 28

Prevents ATP hydrolysis during Ischemia Bridges two synthase molecules, to lock them from spinning Active at lower pH, **low oxygen**

Question 29

How is ADP/ATP transported between the mitochondrial membranes? How is phosphate moved?

Answer 29

Adenine Nucleotide Translocase Antiporter Relies on movement of **protons going down their gradient** **- -** **Phosphate** enters via **symport** with hydrogen

Question 30

Non Shivering Thermogenesis Brown Fat

Answer 30

Uncoupling proteins (**UCP1**) or thermogene expressed in BAT breaks proton gradient, causes heat release - - Brown fat contains more mitochondria, activated by cold and exercise

Question 31

What is source of many ROS?

Answer 31

CoQ is "leaky" and can be partially reduced

Question 32

What does mass leakage of Cytochrome C initiate?

Answer 32

Apoptosis

Question 33

What are the prosthetic groups and co-substrates required by PDH?

Answer 33

TPP (E1) - Transfer alkyl group Lipoate (E2) - Oxidation and transfer of an acyl group CoA (E2) - Co-substrate, Acetyl acceptor FAD (E3) - Oxidation of lipoate NAD (E3) - Co-substrate, oxidation of FADH₂

Question 34

What is primary mchanism of PDH regulation?

Answer 34

Phosphorylation **Activate=Phosphatase** **Inactivate=Kinase:** NADH, Acetyl-CoA **(end products)**

Question 35

What are the irreversible (favorable) steps of the Citric Acid Cycle?

Answer 35

1. Citrate Synthase 2. Isocitrate Dehydrogenase 3. a-Ketoglutarate Dehydrogenase

Question 36

What is the origin of Carbon atoms lost in the Citric Acid Cycle?

Answer 36

OAA

Question 37

How many electrons can CoQ carry?

Answer 37

2

Question 38

What is purpose of IF1?

Answer 38

Prevents ATP Synthase from working in reverse when proton concentrations are flipped

Question 39

How many protons are required per ATP?

Answer 39

4 (3+1) 3x ATP Synthase 1x for Pi Symport