Mitochondria

Question 1

Whats the composition of the mitochondrial matrix and what are its main functions

Answer 1

super concentrated, gel like.

energy metabolism (CAC, pyruvate)
protein processing
protein expression

Question 2

What happens in the inner membrane of the mito?

Answer 2

ox phos, atp synth, high proton gradient , super high protein density made of cristae, contains cardiolipin

fairly impermeable, some proteins transported

Question 3

Whats the composition of the intermembrane space and what are its main functions

Answer 3

much more dilute than matrix. cytocochrome C (means mito ruptured) and transphosporylation kinases

Question 4

Whats the composition of the outher membrane and what are its main functions

Answer 4

heat shock protein and lipid synthesis
super permeable
porin (VDAC)
SAM and TOM protein importers

Question 5

what protein complex helps cristae to form/organize?

Answer 5

Mitochondrial inner membrane organizing system (MINOS)

Question 6

Which lipids are in mitochondrial membranes?

Answer 6

PC-phosphatidylcholine
PE-phosphyatidylethanoline
CL-cardiolipin specific to mitochondrial (inner membrane)
• Totally different structure, 4 fatty acids, 3 glycerol

Question 7

How do mitochondria maintain equilibrium? in what state is one more than the other

Answer 7

fission when full, fusion when starved to conserve

Question 8

What disease is linked to mitochondrial protein processing issues/altered mito. composition?

Answer 8

Diabetes

Question 9

What disease is linked to defect in fission/fusion and accumulation of damages mito?

Answer 9

Parkinsons

Question 10

What disease is associated with defect in chain/free radicals?

Answer 10

aging

Question 11

which diseases are associated w mitochondrial dysfunction

Answer 11

Diabetes, neurodegenerative diseases, and aging

Question 12

Whats living proof of the endosymbiotic hypothesis?

Answer 12

that theres both nuclear and mitochondrial DNA in eukaryotic cell (anaerobic nucleated ate aerobic)

Question 13

what % of mito proteins are encoded by mtnda v ndna?

Answer 13

1%, only 13 vs 1000 in n dna…almost everything is encoded by nuclear dna

Question 14

what does mitochondria need to import? what does it have for dna rep?

Answer 14

almost everything, esp RNA polymerase and ribosomes

has its own rrna and tnra

Question 15

What are 3 characteristics of the mt DNA

Answer 15

dense gene packing (not much regulation)
relaxed codon usage (fewer trna required)
variant genetic code

Question 16

mitochondrial diseases are caused by mutations in what 2 types of dna? what are common characteristics of issues.

Answer 16

nuclear and mito dna. neuromuscular and cardiac

Question 17

What two characteristics of mtdna and its division/expression contribute to phenotype?

Answer 17

1. heteroplasmy (lots of dif copies of mtdna and each, so need 50% mutated to be messed up)
2. mitotic segregation (during cell division dna goes dif places so variable expression)