Biochemistry Exam 3: Mitochondria, Apoptosis, Ros

Front 1

How many CO2 does the full oxidation of glucose yield?

Back 1

6 CO2

C6H12O6 + 6O2-----------> 6CO2 + 6H20

Front 2

What are the NADH and FADH2 quantities produced from one molecule of glucose as it passes through glycolysis, krebs, and pyruvate oxidation?

Back 2

10 NADH
2 FADH2

Front 3

Oxidative phosphorylation uses NADH and FADH2 to reduce _____________ to H20?

Back 3

O2

Note: The energy generated drives the phosphorylation of ADP------------> ATP

Front 4

What is the chemiosmotic theory?

Back 4

Reducing energy of NADH is used to pump protons across the inner mitochondrial membrane creating an energy gradient that is used to make ATP.

Front 5

Mitochondria have _________________ genomes?

Back 5

circular

Front 6

What type of ribosomal RNA do mitochondria have?

Back 6

70S

Note: Prokaryotes have 70S

Front 7

Mitochondria reproduce by ____________?

Back 7

Fission

Front 8

The inner mitochondrial membrane resembles __________________ membranes?

Back 8

Bacterial

Front 9

What are the two names of the enzyme for complex I of the mitochondria?

Back 9

1) NADH Dehydrogenase (Common name)
2) NADH-coenzyme Q-Reductase

Front 10

What are the two possible names of the enzyme for complex II of mitochondria?

Back 10

1) Succinate Dehydrogenase
2) Succinate coenzyme Q reductase

Front 11

Name of the enzyme associated with complex III of mitochondria?

Back 11

1) Cytochrome bc-1 complex
2) Coenzyme CoQ
3) Cytochrome c reductase

Front 12

Name of the enzyme associated with complex IV of mitochondria?

Back 12

Cytochrome c oxidase

Front 13

Complex I passes a pair of electrons from NADH to ____________?

Back 13

CoQ

Front 14

What are the prosthetic groups of complex I?

Back 14

1) Flavin mononucleotide
2) Eight non-heme Fe2+/Sulfur clusters

Front 15

Process by which complex I passes electrons to CoQ?

Back 15

1) NADH + H donates 2 e- and 2 H+ to FMN
2) FMN donates 2e- and 2H+ to Fe2+/Sulfur
3) Fe2+/Sulfur donates 2e- and 2 H+ to CoQ
4) CoQ-----------> CoQH2

Note: Part of the energy produced is used to pump 4 H+ across the inner mitochondrial membrane. Electrons and Protons generally move together.

Front 16

Complex II passes a pair of electrons from _____________ to CoQ producing fumarate?

Back 16

Succinate

Front 17

What are the prosthetic groups of complex II?

Back 17

1) FAD
2) Fe2+/Sulfur complex

Front 18

Process by which complex II passes electrons from succinate to CoQ?

Back 18

1) Succinate donates 2e-/2H+ to FAD
-Requires the succinate dehydrogenase of complex II
-Produces FADH2
2) FAHD2 sends 2e-/2H+ to Fe-S complex
3) Fe-sulfur complex sends 2e-/2H+ to CoQ
4) CoQH2 is produced

Front 19

Does the process by which complex II passes electrons from succinate to CoQ transport any electrons across the inner mitochondrial membrane? Why or why not?

Back 19

No, because the electrons on complex II started out with less energy because of the nature of complex II not being able to create a significant energy gradient for that transport.

Note: Complex II is also not a transmembrane protein

Front 20

What is another name for Coenzyme Q?

Back 20

Ubiquinone

Front 21

CoQ is a protein rich electron carrier? T or F

Back 21

False, non-protein electron carrier

Front 22

CoQ receives electron from complexes I, complex II, and other courses and transports them to complex _________?

Back 22

complex III

Front 23

What is electron transport flavorprotein?

Back 23

An electron scavenger in mitochondria that brings electrons to CoQ

Front 24

Complex III passes electrons from CoQ to ___________?

Back 24

Cytochrome c

Front 25

How many CoQH2's are involved in complex passing electrons to cytochrome c?

Back 25

2 CoQH2

Front 26

What is the pathway of complex III that regenerates CoQH2?

Back 26

1) One of the 2 CoQH2's passes 2e-/2H+ to cytochrome b and it reduces
2) Reduced cytochrome b passes 2e-/2H+ back to CoQ to produce CoQH2

Front 27

What is the pathway of complex III that passes electrons to cytochrome c?

Back 27

1) One of the 2 CoQH2's passes 2e-/2H+ to Fe/Sulfur complex and it reduces
2) Fe/Sulfur reduced complex passes on 2e-/2H+ and reduces cytochrome c1
3) Reduced cytochrome c1 passes on 1e-/1H+ per cytochrome c
4) Each of 2 cytochrome c's are now reduced

Front 28

How many net CoQH2 does complex III use?

Back 28

1 CoQH2

Front 29

How many protons does complex III transport across the inner mitochondrial membrane in the process of reducing cytochrome c?

Back 29

4 protons

Front 30

Complex IV passes electrons from cytochrome c to _______________?

Back 30

O2

Front 31

Process by which complex IV passes electrons from cytochrome c to O2?

Back 31

1) A total of 4 reduced cytochrome c's transfer 4e- to 4 copper-A complexes
2) Reduced Cu-A complex complexes with 4 cytochrome a complexes
3) Cytochrome a/Cu-A complex transfers 4 e- to O2
4) 2 H20 molecules are made

Note: The coefficients are doubled in order for the complete breakdown of one O2 molecule

Front 32

How many protons and electrons does complex IV transport across the inner mitochondrial membrane?

Back 32

It is unclear.

Front 33

What is the significance of the heme groups in cytochromes?

Back 33

They are critical for electron transfer as they contain Fe2+ groups

Front 34

What is complex V and what does it do?

Back 34

Complex V= ATP synthase

-It makes ATP using the stored energy from the protons and electron gradient

Front 35

About how many protons are required to make each ATP using complex V?

Back 35

About 4 protons

Front 36

How does proton movement cause ATP production at complex V?

Back 36

1) Proton moves through F(zero) causes the protein to spin bringing ADP and ATP together

Note: review on slides

Front 37

What is the function of adenine nucleotide translokase?

Back 37

Catalyzes transport of ATP out of the mitochondrial cytoplasm (Matrix) into the intermembrane space in exchange for an ADP which enters the mitochondrial matrix

Front 38

How is the adenine nucleotide translokase reaction driven?

Back 38

Takes advantage of the charge gradient across the mitochondrial membrane

Front 39

How do phosphates enter in to the inner mitochondrial membrane?

Back 39

They use a symport mechanism with the proton gradient that resides out the membrane. Negative phophates transport together with the positive proton.

(Electro neutral symport mechanism)

Front 40

Two mechanisms by which NADH is transported from outside the inner mitochondrial membrane to the inside of the inner mitochondrial membrane?

Back 40

1) Glycerol-phosphate Shuttle
2) Malate-Aspartate Shuttle

Front 41

Process by which the electrons from NADH made in the cellular cytoplasm can enter the inner mitochondrial matrix via the glycercol-phosphate shuttle?

Back 41

1) Glucose reacts to form glyceraldehyde which reacts with NADH and alcohol dehydrogenase to form glycerol. Glycerol then reacts with glycerol kinase to form glycerol-3-phosphate
2) Glycerol-3-phosphate can be transported in to the inner mitochondrial membrane
3) It then reduces FAD to FADH2
4) FADH2 can enter the electron transport chain at complex II

Note: This shuttle is not as efficient as the malate-aspartate shuttle

Front 42

What is the process by which the malate-aspartate shuttle works?

Back 42

1) OAA from TCA reacts with glutamate to form aspartate via transaminase
2) Aspartate diffuses across the membrane into cytoplasm where it can become OAA again via transaminase
3) The 2 NADH's that are produced via breakdown of glucose to two molecules of pyruvate can interact with an OAA from the TCA to form Malate
4) Malate crosses into inner mitochondrial membrane donates electrons to NAD+ and becomes OAA again

Front 43

In what animals are the ced genes located?

Back 43

c-elegans

Front 44

What are the roles of the genes ced-3 and ced-4 in programmed cell death?

Back 44

If they are present programmed cell death will occur

Note: Ced-3 and ced-4 mutants avoid programmed cell death

Front 45

What is the role of ced-9?

Back 45

Orchestrates which cells will be killed by ced-3 and ced-4

Note: If ced-9, ced-3, and ced-4 were absent, there would be no programmed cell death

Front 46

What is the result if ced-9 is not present?

Back 46

In normal animals there will be death

Front 47

What is the Bcl-2 gene (human gene) related to in c. elegans?

Back 47

ced-9

Note: Bcl-2 gene codes for many more complicated processes

Front 48

What are caspases (human proteins) related to in c. elegans? What do they do?

Back 48

ced-3, chop up cellular proteins

Front 49

What is Apaf (human gene) related to in c. elegans?

Back 49

ced-4

Front 50

What is the function of ced-4?

Back 50

Helps activate ced-3

Front 51

What is the function of egL-1 in c. elegans?

Back 51

Interacts with ced-9 to carry out programmed cell death

Note: Human analog is still Bcl-2 family

Front 52

What is the role of Apaf-1?

Back 52

Regulate caspases

Front 53

On the surface of which organelle are the ced-9/Bcl-2 proteins found?

Back 53

Surface of mitochondria

Front 54

egL-1 regulates _______________ which then regulates _______________ which turns ced-3 on or off?

Back 54

ced-9, ced-4