Citrate Cycle/ETC

Question 1

How many ATP, NADH, FADH, CO2 are produces in the Citrate Cycle?

Answer 1

1 ATP, 3 NADH, 1 FADH, 2 CO2.

Question 2

What molecules are sources for making AcetylCoA?

Answer 2

Amino Acids, Glucose, Ketones, Fatty Acids.

Question 3

What are the irreversible enzyme steps in the CC? What are their inhibitors?

Answer 3

1. Citrate Synthase: None
2. Isocitrate Dehydrogenase: ATP, NADH
3. a-ketoglutarate dehydrogenase: ATP/GTP, NADH

Question 4

What is the purpose of the Electron Transport Chain?

Answer 4

To transport electrons from donated NADH or FADH2 to reduce O2 to H2O and establish a proton gradient.

Question 5

What is the purpose of oxidative phosphoryltion?

Answer 5

To generate ATP by ATP synthase using the proton gradient formed by ETC.

Question 6

Complex 1 contains what parts? Accepts electrons from what?

Answer 6

Has an NADH dehydrogenase and proton pump. Accepts electrons from NADH.

Question 7

Complex 2 contains what parts? Accepts electrons from what?

Answer 7

Succinate Dehydrogenase. Accepts electrons from FADH2.

Question 8

what accepts electrons from complex 1 and 2? Where does it pass it on? Special characteristics?

Answer 8

CoQ. Passes it to Complex 3. Lipid soluble.

Question 9

What accepts electrons from complex 3? Passes it where? What are its special characteristics?

Answer 9

CytC. Passes it to Complex 4. Contains a heme group and requires iron.

Question 10

What co-factor does Complex 3 contain? What does it also do in addition to passing on electrons?

Answer 10

It has a heme group and pumps protons.

Question 11

What co-factors does COmplex 4 contain? What does this complex do?

Answer 11

Contains iron and copper. Reduces O2 to H2O and pumps protons.

Question 12

Where does the electron transport chain occur? Where does the proton gradient build?

Answer 12

Occurs on the inner membrane of the mitochondria. Protons build up in the intermembrane space between the outer and inner membrane.

Question 13

how many H+ are required for the ATP synthase to create 1 ATP?

Answer 13

4H+= 1 APT

Question 14

What does Adenine Nucleotide Translocase (ANT) do?

Answer 14

Transports ATP across Inner Mitochondrial membrane to intermembrane space. Transports ADP from the Intermembrane space into the matrix.

Question 15

What does the Voltage-dependent Anion Channel (VDAC) do?

Answer 15

Transports anions, including ATP, across outer mito membrane from intermembrane space. Transports ADP from cytoplasm into intermembrane space.

Question 16

Describe the Malate-Aspartate Shuttle.

Answer 16

1. NADH –>NAD+ from oxaloacetate to malate
2. Malate shuttle into mitrochondrial matrix
3. NAD+–>NADH from Malate to Oxaloacetate
4. Oxaloacetate to Aspartate—>cytosol
5. Aspartate to oxaloacetate.

Question 17

Describe the Glycerol 3-Phosphate Shuttle.

Answer 17

1. NADH–>NAD+ from glycerol-3P synthesis
2. FAD–>FADH2 on outside of inner membrane by re-oxidation of G-3P
3. G-3P Dehydrogenase transports FADH2 e- to CoQ

Question 18

What do each of these subunits do in ATP Synthase? c,a,(y)gamma, (a/b) alpha/beta,

Answer 18

c= binds to H+ and turns
a=channel H+ go to matrix
y=every 3H+ in c turns this 120 degrees
a/b=pair can bind to ADP and Pi to create ATP