Midterm 1 Vocab Flashcards
Yeast Characteristics
-genome around 6000 genes
-32 linear chromosomes
-facultative aerobe
-around 650 species
unicellular
haploid and diploid life cycle phases
Yeast haploid life cycle
- mother cell starts to bud
- bud grows and splits off
- bud scar left behind
- after many divisions, cell covered in bud scars and can no longer divide
Diploid formation
- 2 yeast cells of opposite mating types schmoo together
- cells contact and cell walls dissolve
- plasmogamy
- nuclei fuse (karyogamy)
thallus
term for bodies of fungi or lichen
homothallic
sexual reproduction with a single thallus; mates with itself
heterothallic
sexual reproduction with two different thalli
positive selection
selects for cells with WT gene copy
Determining Mating type: testing for secreted pheromones
- seed plate with sensitive strain of yeast
- mating factor diffuses from filter paper patch of an unknown mating type
- lawn grows
- dark “halo” around sensitive cells of the opposite mating type that are stopped in G1
Determining mating type: crossing with known types
- agar streaked with yeast cells on rich media w/ a selectable marker
- test crosses with strains of known mating types
- incubate
- replica plate onto media lacking uracil and lysine
- use phenotype to determine query strain
Isolating haploids
- collect asci
- use enzymes to open asci and release the ascospores
- separate ascospores onto agar
- replica plate onto media lacking lysine and onto media lacking uracil
- use phenotypes to score tetrad
tetratype (T)
both parental and recombinant genotypes present
parental ditype (PD)
all genotypes the same as parents
nonparental ditype (NPD)
all genotypes different from parents
uniparental inheritance
inherited from a single parent (ex. mitochondria)
pyruvate dehydrogenase
makes acetyl coA
PDH kinase
adds deactivating phosphate to PDH to regulate
PDH kinase inhibitors
NAD+, ADP, SH-coA
PDH kinase activators
NADH, acetyl coA
PDH phosphatase
removes deactivating phosphate to activate PDH; regulated with calcium
Reactions catalyzed by PDH
- removal of pyruvate carboxyl group
- remaining 2C molecule oxidized and NAD+ reduced
- coenzyme A attached via sulfer atom to make acetyl coA
respirosome
physical association of complexes 1, 3, and 4 in the ETC; reduces buildup of ROSs; needed for complex 1 stability
brown adipose
tissue used to make heat in non-shivering thermogenesis; heat made with uncoupler UCP1
UCP mechanism
- long chain FA anions trapped by hydrophobic interactions of long tails in their symporter
- oscillates back and forth
- unable to dissociate, so only H transported
dinitrophenol
uncoupling drug that increases permeability of MIM to H
heteroplasmy
multiple different genomes within a single cell
twinkle
mtDNA helicase
Initiation of mtDNA Replication
- twinkle binds Ori H, and unwinds short DNA section
- POLRMT initiates transcription from LSP; provides 3’ primer to start synthesis
- twinkle passes TAS
- new strand displaces parental H-strand, making D-loop; coated in mtSSB
- pol gamma replicates DNA
- ori L displaced and forms stem loop; primer made on stem loop, and H-strand replicated
- RNase H removes primer
- DNA ligase repairs backbone
rCRS
revised cambridge reference sequence
haplogroups
groups of humans based on mtDNA differences
mitochondrial eve
hypothetical common ancestor of all human mtDNA
TFAM
transcription factor A, mitochondrial; binds DNA without sequence specificity, binds, wraps, and bends DNA for compaction; Recruits POLMRT to promoter to initiate transcription
ATAD3
ATPase triple A domain containing proteins; act as scaffold; binds TFAM and ribosomes to improve efficiency of transcription and translation
Transcription steps
- HSP and LSP recruit POLRMT
- mtDNA transcribed into 2 polycistronic transcripts
Transcription initiation
- TFAM recruits POLRMT and promoter recognized
- TFB2M changes POLRMT to induce DNA melting
TFB2M
transcription factor B2
TEFM
transcription elongation factor, mitochondrial; promotes POLRMT ability to add nucleotides; required for elongation; acts as switch between transcription and replication
transcript maturation
endonuceotytic exision of mt-tRNA releases mRNAs and rRNAs
- tRNA punctuation model
- RNase P binds 5’ side of tRNA transcript, RNase 2 binds 3’ end
- other transcripts released
- 3’ adenylation completes stop codon
- rRNAs join with proteins to make ribosomes
- tRNAs associate with amino-acyl tRNA synthetase
ribozymes
RNA with enzymatic properties