Mitochondria and Disease

Question 1

2 highly specialized membranes

Answer 1

1. Mitochondrial inner membrane

2. Mitochondrial outer membrane

Question 2

Mitochondrial outer membrane

Answer 2

• separates from the cytosol
• contains many porins
• permeable to certain molecules

Question 3

Mitochondrial inner membrane

Answer 3

• highly impermeable

- contains large amounts of cardiolipin

Question 4

Mitochondrial mobility

Answer 4

Mitochondria are highly mobile, move along microtubule network and accumulate at energy-demanding parts of the cell

Question 5

Differentiating cells

Answer 5

Numerous morphologically and functionlly distinct mitochondria

Question 6

Metabolic activity cells

Answer 6

• dissipation of energy
• development
• defense against aging
• mitochondria can form a mitochondrial reticulum/network

Question 7

Mitochondrial matrix

Answer 7

Citric acid cycle generates high energy electrons through oxidation of substrates

Question 8

Mitochondrial inner membrane

Answer 8

Electrons are donated via NADH to the respiratory chain

Question 9

Glycolysis

Answer 9

Eectron carriers transport electrins to reactions in the mitochondria

Question 10

Biosynthesis

Answer 10

Production of key intermediates for biosynthesis of nucleotides, lipids, gluthione etc.
- ananolic reaction

Question 11

Degradation

Answer 11

• amino acid degradation (urea cycle)
• lipid degradation
• catabolic reaction

Question 12

Virtually all mitochondrial proteins are

Answer 12

• encoded by genes in the nucleus
• synthesized on cytosolic ribosomes
• imported from cytosol into mitochondrion
• protein transport is unidirectional

Question 13

Initial steps in mitochondrial protein import

Answer 13

• binding of signal sequenxe to receptor
• chaperones and other associated proteins are removed
• unfolded polypeptide chain enter TOM complex

Question 14

SAM

Answer 14

Sorting and assembly machinery

Question 15

Mim1

Answer 15

Supports assembly if -barrel protein

Question 16

Mdm

Answer 16

Mitochondrial distribution and morphology

Question 17

Mmm1

Answer 17

Maintenance of mitochondrial morphology

Question 18

Kearns-Sayre syndrom (KSS)

Answer 18

External ophthalmoplegia, cardiac conduction defects, and sensorineural hearing loss

Question 19

Peber hereditary optic neuropathy (LHON)

Answer 19

Visual loss in young adulthood

Question 20

Myoclinic epilepsy and ragged-red fibre (MERRF)

Answer 20

Progressive myoclinic epilepsy, clumps of diseased mitochondria accumulate in the subsarcolemmal region of the muscle fibre

Question 21

Leigh syndrome (SNEM)

Answer 21

Seizures, altered states of consciousness, dementia, ventilatory failure

Question 22

Neuropathy, ataxia, retinitis pigmentosa, and ptosis (NARP)

Answer 22

Dementia, in addition to symptoms described in the acronym

Question 23

Myoneurogenic gastrointestinal encelopathh (MNGIE)

Answer 23

Gastrointestinal pseudo obstruction, neuropathy

Question 24

Heteroplasmy

Answer 24

Mix of multiple mtDNA copis per mitochondrion of which some mutated

Question 25

Threshold expression

Answer 25

Number of affected mitochondria have ti reach certain level before mitochondrial disease clinically apparent

Question 26

Mitotic segregation

Answer 26

Daughters and sons inherit this mix, will be healthy unless process mitotix segregation result in majority of defective mitochondria in particular tissue

Question 27

Tim22 complex

Answer 27

Promotes insertion of multipass membrane proteins into the inner membrane

Question 28

Diagnosis of mitochondrial disease

Answer 28

• Metabolic testing
• muscle testing
• genetic testing

Question 29

What do mitochondrial metabolites do?

Answer 29

• signaling

- regulate cellular gene expression

Question 30

Where is mitochondrial genetic system located?

Answer 30

In the mitochondrial matrix