Mitochondria

Question 1

What did mt. descend from?

Answer 1

Protobacteria

Question 2

Do mt have their own genome?

Answer 2

Yes

Question 3

How many mt proteins have been detected?

Answer 3

670 are imported and 13 are made from the mitochondrial genome

Question 4

How many proteins does the mt genome encode for?

Answer 4

13

Question 5

How many membranes does a mt have?

Answer 5

2

Question 6

What type of bacteria did mt. descend from?

Answer 6

Alphaprotobacteria

Question 7

What is contained within the mt.intermembrane space?

Answer 7

Cyt-c

Question 8

What is contained within mt. matrix?

Answer 8

TCA enzymes, PDH complex, beta ox enzymes, DNA, RNA, ribosomes, ATP,ADP,Pi, ions, etc.

Question 9

What controls ATP flux in mitochondria?

Answer 9

Cristae contacts with inner membrane

Question 10

Describe a mt. under active respiration.

Answer 10

Condensed matrix, expanded intermembrane space, proton pumping into intermembrane spacecauses water to follow and swells membrane

Question 11

What protein controls contact of cristae with mt. inner membrane?

Answer 11

Mitofilin-this is a test question almost 100% sure

Question 12

What are some apoptotic mitochondrial signals?

Answer 12

Bad, Bix, Bax, etc. causes mt. membrane to become leaky and form pores that cause cyt-c to leak and couple with Apaf-1 which results in a caspase cascade and cell death

Question 13

What structure does a porin have? What is the largest wt. molecule that can pass?

Answer 13

Beta barrel, 5kDa

Question 14

What is cardiolipin formed from?

Answer 14

Glycerol with 2 FA

Question 15

What portion of cardiolipin associates with mt. inner membrane?

Answer 15

Unsaturated FA

Question 16

If FA is not saturated then what can this cause?

Answer 16

Cardiomyopathy, barth syndrome

Question 17

Describe a mitochondrial carrier protein

Answer 17

Can carrier lots of small molecules, has structure with 6 transmembrane helices, antiporters , alternate conformations based on salt bridgeskinks formed by proline residues in active site, highly conserved structure

Question 18

What anion can damage almost any intracellular product? What reduces it?

Answer 18

Superoxide; superoxide dismutase

Question 19

What can convert hydrogen peroxide to oxygen and water.

Answer 19

Catalase

Question 20

What reduces hydroxyradical?

Answer 20

Vit C, Vit E

Question 21

How many e- does it take to get from oxygen to water?

Answer 21

4

Question 22

What proteins are found in the apoptisome

Answer 22

Cytacrome-C APAF-1 and Capase-9

Question 23

Mitochondrial functions include what?

Answer 23

TCA cycle, respiration, fatty beta oxidation, ammonia elimination via urea cycle, heme biosynthesis, protection against oxidative stress, RNA/DNA/protein biosynthesis, Mt biogenesis, molecular transport, calcium uptake/release

Question 24

What does the inner membrane hold?

Answer 24

inner membrane holds ETC and ATP synthase as well as set of carrier proteins required for exchange metabolites

Question 25

Describe active respiration wrt to ADP and what happens to the mitochondria?

Answer 25

-oxygen concentration drops rapidly until ADP runs out
-Mt changes appearance=>
Low [ADP]=> moves from condensed to expanded (orthodox)

High [ADP]=> moves from orthodox to condensed

Question 26

What protein in the Mt has been linking to cristae morphology and is part of the Mt inner membrane organizing system?

Answer 26

mitofilin

Question 27

Describe how Mt is important in apoptosis

Answer 27

B, B, B gives a pro-apoptotic signal that causes Mt to become leaky and release cytochrome c into the cytosol
-cytochrome c unites with Apaf-1 to recruit caspase 9 which form the apoptosome that triggers a caspase cascade for cell death

Question 28

What are caspases?

Answer 28

cysteine proteases that must be activated

Question 29

What is the protein that is significant in the outer membrane of the Mt?

Answer 29

porin

Question 30

What is the unique phospholipid in the inner membrane? What are the results if the protein is disrupted?

Answer 30

cardiolipin => Barth syndrome=> defective Mt, cardiomyopathy, muscle weakness

Question 31

What can move across the inner membrane easy?

Answer 31

water, oxygen, CO2

Question 32

ADP, ATP, phosphate, pyruvate, and other AA need special transporters are what?

Answer 32

mitochondrial carriers

Question 33

What helps to stabilize the different conformations of the Mt carriers?

Answer 33

charge pairs at the matrix membrane surface shift during the transport cycle

Question 34

What do diseases of Mt origin result in?

Answer 34

production of ROS

Question 35

What is the goal of respiration?

Answer 35

reduce oxygen to water and in the process to capture energy of electrons removed from pyruvate

Question 36

What happens to if one electron is added to oxygen? If the enzyme to eliminate this is not present, what will occur?

Answer 36

superoxide anion

oxidative stress linked to alzheimers, parkinsons, aging

Question 37

What occurs or is found in the Mt matrix?

Answer 37

1. pyruvate DH complex
2. citric acid cycle enzymes
3. fatty acid oxidation enzymes
4. AA oxidation enzymes

Question 38

As respiration increases, what happens to the christae in the IM space? What protein regulates this?

Answer 38

it increases its openness regulated by mitofilin

Question 39

ROS are needed for some of the proper insulin signaling. What will occur if this does not happen?

Answer 39

No ROS=> type II diabetes

Question 40

What 2 vitamins are important in scavenged for the hydroxyl radicals?

Answer 40

vitamin c and e