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57 Cards in this Set
- Front
- Back
What is extranuclear inheritance?
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inheritance patterns involving genetic material outside the nucleus
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Mito and chloroplasts contain
These organelles are found in the therefore extranuclear inheritance is also termed |
Dna
cytoplasm cytoplasmic inheritance |
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The genetic material of the mito is located in a region called?
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nucleoid
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The genome of organellses usually consists of a singular _______ chromosom
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circular
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A nucleoid may contain several copies of the ________
the organelle contains many____________ a cell contains many _________ therefore there are numerous copies of organellar _________ per cell |
genome
nucleoids organells genome |
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T/F: Sizes of the mito genome in selected organisms are very diverse
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t
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Whats more stable: circular mtDNA or linear mt DNA
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circular
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Circular DNA is present at a thousand times higher copy number than linear. T/F
Therefore the mito DNA can be sometimes sequenced from _______ samples |
True
extinct |
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Give examples where mtDNA was sequenced from extinct samples
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wolly mammoth and world trade center
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What theory descrices the evolutionary origin of organelles?
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endosymbiotic theory
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The theory holds that encestral eukaryotic cells grew _____ and lacked ________ and chloroplasts.
These early cells engulfed an aerobic _____-_______bacterium which evolved into a ________. |
anaerobically , mito
alpha- proteo, mitochondrion |
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Likewise, endocytosis of a photosynthesizing bacterium led to the evolution of modern eukaryotic cells with mito and ________.
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chloroplasts
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Mitochondria uses ___. This provides a great advantage for ______ production.
Chloroplasts allow fixation of ________ from the air. |
O2, ATP
CO2 (carbon) |
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Evolution of mito genomes:
During evolution, how did the organellar genomes gotten smaller? 2 basic mechs |
transfer of genes to nuclear genome
loss of genes that were no longer requird |
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mOST MITO PROTEINS ARE ENCODED BY GENES IN THE ________
tHESE PROTEINES ARE FIRST MADE IN THE_______ THEN TRANSPORTED TO THE MITO tHE HAVE MITO TARGETING SIGNALS IN THERE __________ TERMINAL ENDS |
nucleus, cyto, amino
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Mito DNA has a ______ mutation rate than nuclear DNA.
This makes it useful in the study of close evolutionary __________ within species. Examples Mitochondrial Eve and Out of africa hypothesis describes? |
higher, relationships
hypotheses of human origin and migration |
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The mito genetic code differes in a _____ codons from the nuke code.
UGA usuall encodes stop but in mito it encodes: AUA usually isoleucine but in mito: AGA usually arginine but in mito: |
stop, in mito tryptophan
methionine Vetebrate mito - STOP drosophilia mito - SERINE Yeast mito - arginine |
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The 22 human mito tRNA are all encoded in the __________ genome and have expanded _________.
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mitochondria, xpanded
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Does the mito genome have histone prots?
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no
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Does it have pre-mRNA introns?
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No
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Polycistronic DNA?
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YES
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5' cap added to mRNA?
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NO
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3' POLY A til added to mRNA?
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some animals
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Shine delgarno sequence in 5" UTR of mRNA?
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RARE
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NON UNIVERSAL CODONS AND EXTENDED WOBBLE?
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YES
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The human mtDNA consists of _____ bp?
It only carries _____ genes: ___ rRNAs ____ tRNAs ____ mRNAs that encode polypeptides functioning in oxidative phosphorylation to make ATP |
16569
37 2 22 13 |
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human mtDNA is high _________ in organization.
it is replicated by DNA polymerase ______ there are few ________ regions There are no _________. (budding yeast mtDNA has 2 ______-________ group II introns) |
economical
gamma, non-coding, introns, self-splicing |
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Human mtDNA is circular or linear?
Outside strand is called? Inside strand is called? _____ strand codes for only ____ protein and 8 ______. tHE PROTEIN IT ENCODES IS CALLED ______? wHAT KIND OF GENES ARE FOUND ON MTDNA? 3 KINDS |
circular
heavy strand H light strand L L, 1, tRNA, ND6 tRNA , PROTEIN, and rRNA genes |
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Is the mechanism of mito DNA replication symmetric or assymetric?
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assymetric
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RNA primer initiates replication at origin on ___ strand.
After RNA synthesis of primer is initiated, RNA is ______ and ________ is syntheszed. Synthesis of new ___ strand creats ____ loop by ________ parental strand. __ loop then expands. |
H
degraded, DNA L, D, displacement D loop |
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When the displaced strand passes origin on L strand, synthesis of new _____ strand starts.
Completion of new L strand releases _______ genomes |
H, daughter
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Review slide 18
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now
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the mtDNA replication machinery
the mito polymeras gamma is a _______trimer of one _______ subunit called gamma A and two ________ subunits gamma B. These increase processivity. |
hetero, catalytic, accessory
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What is the mitochondrial DNA helicase?
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ttwinkleeee
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Mitochondrial DNA mutations and repair systems
MAMMALIAN: HAVE A _________ ____________ REPAIR SYSTEM HAVE A ___________ REPAIR PATHWAY (O6-methylguanosine) HAVE AN ALTERED ____________ REPAIR SYSTEM HAVE THE _______ FOR RECOMBINATION REPAIR DOES NOT HAVE __________ EXCISION REPAIR WHICH MEANS THEY CAN NOT REPAIR THYMINE DIMERS EFFICIENTLY |
base excision
direct mismatch enzymes nucleotide |
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How many polycistronic messages cover the 2 strands in mito dna trascription?
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3
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Human mitochondrial DNA (mtDNA) has three promoters?.
The ___ promoter transcribes almost the entire heavy strand and the ___ promoter transcribes the entire light strand. The ____ promoter causes the transcription of the two mitochondrial rRNA molecules: _____ AND ____ |
H1, H2, and L SP (heavy strand 1, heavy strand 2, and light strand promoters)
H2, LSP H1, 12S, 16S |
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What cuts the rRNA and tRNA out from the polycistronic transcripts?
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RNAse P
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mitochondrial mrna lack ____ caps, 5' ____, __________ binding sites, and 3'_________.
most non mammalian also lack.... |
5', UTRs, ribosomal, UTRs
poly-A TAILS |
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ARE MITO RIBOSOMES MORE SIMILAR TO EUKARYOTIC OR BACTERIAL RIBOSOMES?
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BACTERIAL
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what kind of ribosomes do mitochondria have?
are they bigger than bacterial 70s ribosomes? |
55s
yes |
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Mito ribosomes are mostly made of ________. How many?
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protein, there are 85 proteins compared to 53 in e. coli
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What percent of mito ribosomes are RNA?
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25%, compared to 65% RNA for bacterial ribosomes
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mito ribosomes bind to which codons at the end of mitochondrial mRNA?
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AUG, AUA (Met)
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Variations within mitochondrial DNA sequence give rise to ____________, defined as the presence of multiple distinct mitochondrial sequences within an individual.
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heteroplasmy
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there can be variable levels of heteroplasmy in mtdna in different tissues within the ______ individual
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same
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Mitochondrial mutations exhibit a ____________ effect.
Manifestations are produced only when the percentage of mutant mtDNA is above a certain___________. ___% - ___% mutant copies. This varies depending on the tissue |
threshold,
threshold 60 - 80 |
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There is a close relationship between a mutant mtDNA and...
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aging
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mitochondrial DNA deletions accumulate in _________ and ________ with age. This plays a role in _____________ disease.
Also related to age-related loss in ________ mass called __________. |
brain, muscle, parkinsons
muscle, sarcopenia |
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What stimulates the formation of the mtDNA deletions in brain and muscle with age?
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oxidative stress
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Common mito diseases:
Leigh Syndrome _______ onset progressive n_____________ disorder. Lesions are on one or more areas of the ___. (ex: brainstem, cerebellum) there are defects in o____________ p___________ mitochondrial respiratory chain complexes. (Complexes I, II, IV, and V) Mutations in mitochondrial ____ and _______ genes, and also __________ encoded subunits of oxidative phosphorylation. |
Early, neurodegenerative, CNS
oxidative phosphorylation ND5, atp6, NUCLEAR |
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Leber Hereditary Optic Neuropathy (LHON)
presents itsef in ______ as acute or subacute central vision loss which leads to blindness. Most common in _____ around age ___. ___________ mutations in mtDNA (___ -->___ transitions) leads to reduction in mito _________ production, which leads to dysfunction and death of the ______ nerve. Mutations in at least four mitochondrial genes: Mutations at basepairs 11778, 3460, 14484 in mtDNA accounts for 90% of prevalence. |
midlife
men, 20 Missense, G-->A ATP, optic ND1, ND4, ND4L, ND6 - Complex 1 of electron transport |
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MELAS - mitochondrial encephalomyopathy lactic acidosis and strokelike episodes
________ inheritted disease __________ neurodegenerative disorder onset is between ages... ___ different mutations can cause MELAS most common ________ mutation is A3243G of the my-tRNA leu gene deficiency of complex 1 in _________ muscle |
maternally
progressive 2-15 17 point skeletal |
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MERRF - myoclonic epilepsy and ragged red fiber disease
_______system disorder that leads to generalized epilepsy, ataxia, weakness, dementia hearing loss, myopathy, optic atrophy, and neuropathy can result rare disorder 1 in 100,000 begins during _________ or __________. but can onset in ___________. lethal in the absence of some amount of normal mito function |
multi
childhood, adolescence, adulthood |
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Kearns-Sayre Syndrome (KSS)
_____-scale single deletions or ___________ of mtDNA, usually not ________. occurs ________, probably at germ cell level or very early in embryonic development. deletions vary in size from 1.1 to 10 kb and there are more than 150 different deletions associated with KSS. deletions of 4977bp, known as the _______ deletion is most frequently encountered. deletions are present in ___ tissues. |
large, rearrangements, inherited
spontaneously common all |
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Chloroplast DNA is usually ________, but typically _______ than mtDNA.
have genes that encode for _RNA, _RNA, _______ genes, and unassigned ________. |
circular, larger,
rRNA, tRNA, protein, open reading frames (ORF) |
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Sizes of chloroplast genomes do not vary in size as much as mtDNA. T/F
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true
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