Mitochondria/OxPhos

Question 1

What are the mtDNA mutations of Complexes I, IV?

Answer 1

"41 y/o Moms Love Hot Dick Milk"
MELAS
Leigh syndrome
Hypertensions and hypercholesterolemia 
Diabetes with deafness
MERRF

Question 2

What are the symptoms and onset of MELAS?

Answer 2

Onset: infancy to early childhood

Symptoms: muscle weakness, pain, loss of apetite, seizures, and the corresponding symptoms of MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke)

Question 3

What are the symptoms and onset of Leigh syndrome?

Answer 3

Onset: first year of life

Symptoms: difficulty swallowing, weak motor skills, vomitting, lesions in basal ganglia and brainstem

Question 4

What type of mtDNA mutation can be helped with Ubiquinone supplements?

Answer 4

Diabetes with deafness - Complex I, IV mutation

Question 5

What are the symptoms of MERRF?

Answer 5

Muscle spasms, hearing loss, and dementia. MERRF = myoclonic epilepsy and ragged-red fiber disease

Question 6

A superoxide ion (O2-) is converted to H2O2 by what enzyme?

Answer 6

Superoxide dismutase (SOD)

Question 7

H2O2 is converted to H2O by what enzyme(s)?

Answer 7

Catalase and GSH peroxidase (Glutathione peroxidase)

Question 8

A mutation in mtDNA of Complexes III, IV result in what?

Answer 8

"Three, Four = heart is poor"
Hypertrophic cardiomyopathy (exercise intolerance) -- enlargement and degeneration of cardiac muscle

Question 9

What is Kearns-Sayre syndrome? (Cause, Onset, and symptoms)

Answer 9

Cause: All mtDNA complex mutation (I-V)
Onset: before age 20

Symptoms: eye pain, opthalmoplegia, ptosis (droopy eyelid), and pigmentary retinopathy

Question 10

What is Pearson syndrome? (Cause and symptoms)

Answer 10

Cause: All mtDNA complex mutation (I-V)

Symptoms: sideroblastic anemia; exocrine pancreas dysfunction

Question 11

An mtDNA mutation to complexes I, III causes what?

Answer 11

“One, Three = can’t see”
Leber hereditary optic neuropathy (LHON)

Onset: early adulthood

Symptoms: degenerated optic nerve; continued loss of central vision

Question 12

What does Oligomycin do in regards to the electron transport chain (ETC)?

Answer 12

It blocks H+ transport thru Complex V = no ATP formation

Question 13

Complex II is inhibited by what chemical agent(s)?

Answer 13

Malonate (blocks FADH2)

Question 14

Complex III is inhibited by what chemical agent(s)?

Answer 14

Antimycin

Question 15

Complex IV is inhibited by what chemical agent(s)?

Answer 15

CO, Cyanide, and H2S

Question 16

Complex I is inhibited by what agents, and what does this cause?

Answer 16

Amytal, Rotenone, Myxothiazol, and Piericidin A

These can cause MELAS

Question 17

Where does the Malate-Aspartate Shuttle operate and what does it do?

Answer 17

In the heart, liver, and kidney

It helps NADH enter the ETC at complex 1

Question 18

Where does the Clycerophosphate shuttle operate and what does it do?

Answer 18

In skeletal muscle and brain

It helps FADH2 donate it’s electrons to the ETC at CoQ

Question 19

What is the difference between redox pairs and redox couples, and what component of these reactions is the most important?

Answer 19

Redox pairs: between 2 molecules (e.g. NAD+/NADH) –> important because it requires electron transfer WITH protons (H+)

Redox couples: between 2 metals (e.g. Fe3+/Fe2+) –> important because it requires ONLY electron transfers with no proton

Question 20

What is an Uncoupled Reaction and what does it cause?

Answer 20

An uncoupled reaction takes place in presence of Uncoupler DNP (2,4-Dinitrophenol) which pushes H+ into matrix before they go to the ETC. This stops ATP production and GENERATES HEAT.

(DNP used in weight loss supplements and given to soviet war soldiers)