Lectures 1-3

Question 1

how do erythrocytes produce ATP and NADH

Answer 1

glycolysis only

Question 2

what is an allele?

Answer 2

an alternate form of a gene resulting from a mutation

Question 3

what is hemizygous?

Answer 3

alleles on X chromosome where there is only a single X chromosome

Question 4

what is mendel’s second hypothesis?

Answer 4

the inheritance of each gene is independent of all other genes

Question 5

what is mendel’s first law?

Answer 5

each gene has two factors (alleles)

Question 6

how are genes mapped?

Answer 6

the total number of recombinant offspring are divided by the total number of offspring

Question 7

how are candidate genes used to identify the disease gene?

Answer 7

these genes are cloned from both affected and normal people, the clones are then analyzed to see if the affected people have genes that are mutated that the normal people do not have.

Question 8

how many copies of mtDNA are there per cell?

Answer 8

500-150,000

Question 9

how many copies of mtDNA per mitochondrion?

Answer 9

5-10

Question 10

what are the stop codons for mitochondrial DNA?

Answer 10

AGG and AGA

Question 11

what do the majority of mitochondrial genes code for?

Answer 11

RNA involved in translation

2 rRNA and 22 tRNA (24/37 total)

Question 12

what do the minority of mitochondrial genes code for?

Answer 12

proteins involved in electron transport (13/37)

Question 13

how is mtDNA inherited

Answer 13

through the maternal line

Question 14

what is mosaicism?

Answer 14

• the reason offspring of affected mothers rarely show symptoms of her disease
• basically mitochondria are randomly chosen to be incorporated into daughter cells. Founder effect.

Question 15

what is MERRF and what is its cause?

Answer 15

• Myoclinic Epilepsy associated with ragged red fiber

- caused by A to G mutation at nucleotide 8344!

Question 16

what is MELAS and what is its cause?

Answer 16

• Mitochondrial Encephalamyopathy with Lactic Acidosis and Stroke like episodes
• mutations in tRNA and ND genes (3243A-G and 4332G-A)

Question 17

what is LHON and what is its cause?

Answer 17

• Leber Hereditary Optic Neuropathy
• mutations in ND genes G11778A
• most common mutation

Question 18

what disease is caused by deletion mutations in mtDNA?

Answer 18

• KSS (Kearns-Sayre syndrome)

Question 19

what diseases is caused by mutations in nuclear genes?

Answer 19

• Aplers/Ataxia

Question 20

symptoms of mitochondrial diseases increase in severity with what?

Answer 20

• increasing degree of heteroplasmy

- increasing age

Question 21

what is heteroplasmy?

Answer 21

• the presence of a mixture of normal and abnormal (mutated) DNA within a cell.

Question 22

what are the two ways of diagnosing a mitochondriopathy?

Answer 22

a) gomori trichrome staining of muscle biopsy sample lol whatever the fuck that is.
b) measurement of the mitochondrial energy-generating capacity (MEGS)

Question 23

what are the five treatments for a mitochondriopathy?

Answer 23

CRLLLcac

1) CoQ10 (electron carrier)
2) Riboflavin (vitamin B2)
3) L-creatine (intracellular buffer for ATP)
4) L-arginine (precursor of creatine and NO)
5) L-carnitine (transfer compound for fatty acids)

Question 24

37 mitochondrial genes are encoded from how many bp of mtDNA?

Answer 24

16569 bp

Question 25

how many mitochondria per cell?

Answer 25

100

Question 26

what codes for trp in the mitochondrial genetic code?

Answer 26

UGA

Question 27

where are the 13 proteins of the electron transport chain encoded and transcribed?

Answer 27

mitochondrial genome

Question 28

what are some common symptoms of a mitochondrial disease?

Answer 28

• poor growth
• myopathy (muscle weakness)
• poor coordination
• sensory problems
• lactic acidosis
• extreme erections

Question 29

what is ragged red fiber and what is its cause?

Answer 29

• clumps of ineffective or diseased mitochondria in a cell

- result of the cell overproduction of mitochondria after sensing ineffective or diseased mitochondria