Lectures 1-3 Flashcards
how do erythrocytes produce ATP and NADH
glycolysis only
what is an allele?
an alternate form of a gene resulting from a mutation
what is hemizygous?
alleles on X chromosome where there is only a single X chromosome
what is mendel’s second hypothesis?
the inheritance of each gene is independent of all other genes
what is mendel’s first law?
each gene has two factors (alleles)
how are genes mapped?
the total number of recombinant offspring are divided by the total number of offspring
how are candidate genes used to identify the disease gene?
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.
how many copies of mtDNA are there per cell?
500-150,000
how many copies of mtDNA per mitochondrion?
5-10
what are the stop codons for mitochondrial DNA?
AGG and AGA
what do the majority of mitochondrial genes code for?
RNA involved in translation
2 rRNA and 22 tRNA (24/37 total)
what do the minority of mitochondrial genes code for?
proteins involved in electron transport (13/37)
how is mtDNA inherited
through the maternal line
what is mosaicism?
- 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.
what is MERRF and what is its cause?
- Myoclinic Epilepsy associated with ragged red fiber
- caused by A to G mutation at nucleotide 8344!
what is MELAS and what is its cause?
- Mitochondrial Encephalamyopathy with Lactic Acidosis and Stroke like episodes
- mutations in tRNA and ND genes (3243A-G and 4332G-A)
what is LHON and what is its cause?
- Leber Hereditary Optic Neuropathy
- mutations in ND genes G11778A
- most common mutation
what disease is caused by deletion mutations in mtDNA?
- KSS (Kearns-Sayre syndrome)
what diseases is caused by mutations in nuclear genes?
- Aplers/Ataxia
symptoms of mitochondrial diseases increase in severity with what?
- increasing degree of heteroplasmy
- increasing age
what is heteroplasmy?
- the presence of a mixture of normal and abnormal (mutated) DNA within a cell.
what are the two ways of diagnosing a mitochondriopathy?
a) gomori trichrome staining of muscle biopsy sample lol whatever the fuck that is.
b) measurement of the mitochondrial energy-generating capacity (MEGS)
what are the five treatments for a mitochondriopathy?
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)
37 mitochondrial genes are encoded from how many bp of mtDNA?
16569 bp
how many mitochondria per cell?
100
what codes for trp in the mitochondrial genetic code?
UGA
where are the 13 proteins of the electron transport chain encoded and transcribed?
mitochondrial genome
what are some common symptoms of a mitochondrial disease?
- poor growth
- myopathy (muscle weakness)
- poor coordination
- sensory problems
- lactic acidosis
- extreme erections
what is ragged red fiber and what is its cause?
- clumps of ineffective or diseased mitochondria in a cell
- result of the cell overproduction of mitochondria after sensing ineffective or diseased mitochondria
