CH 5 Exam 2 Flashcards
What are architectural proteins?
help fold chromosomoes
what’s the main architectural protein in eukeriotic cells
histones
Size of small geneomes of viruses archaea aand eukaryotes
<10 Mb and <20 Mb. It’s mainly protein coding and RNA coding sequences, nothing else.
How big are large genomes and what do they consit of?
> 100 Mb, majority of it is non-coding, introns and exons are in there, long
what type of genomes is chalk full of coding sequences
small
Do all eukaryotes have the same number of chromosomes?
no
how do u wrap dna up so it can be tight in the chromosome?
using histones
what’s dna called when it’s wrapped around a histone?
nucleosome
what do all the nucleosomes make up?
The 10 nm fiber (chromatin0
what is a histone core made of
8 polypeptides (blue beeds) and a linker (yellow bead)
DNA is blank and histones are blank
negative, positive, ionic reactiosn keep them on
Strutcure of histone proteins
Histone-DNA interactions at the carboxyl terminal end. Histone-fold domain
and lysine and arginine charge at the N terminal
what’s it called when the nucleosomes wrap around each other
30 nm fiber. not clear how it folds
what;s a condensin complex
makes chromosomes more compact, requires atp. it;s a complex
after the condensin complex how many folds are u at
10,000-fold. this is in metaphse.
what special structures can we see during metaphase?
centroomere (onnect sister chromatids), cohesins 9hold sister chromatids together along their length), Ki-67 coats the chromosome repelling other chromosomes.
Centromere has a special…?
sequence that can bind specialy to proteins. Special histone have CENP-A to allow centromeres to do the specil things
kinetochore
assemples at the centromere. allows for capturing spindle microtubles so it can seperate correctly to daughter cells
Metacentric, acrocentric, telocentric
in the imdd,e not quite the middle, at the end
more autosomes or sex chromosomes?
autosome
three levels for gene regulation
sequence of DNA, at the folding into chromatin (is ti tightlyu wound what is it), location of the chromosome inside the nucleous
Ways DNA can be packaged
heterochromatin (tight, can’t read DNA), euchromatin (more open allows gene activation)
C-value
amount of DNA in haploid genome (but doesn’t corrilate w how complex the organizm is)
types of tandom repeates
satelites, minisatelites, STRs
Types of interspersed elements
SINE (11%) and LINE (21%)
where does lateral gene transfer happen
organelle geneomes. mitochon and chloroplasts
Endosymbiont hypothesis
both organelles (mitochon and chloro) are derived from primitive, free-living, bacterial-like organisms
Mitochondrial DNA
encodes essential enzymes for oxidative phosphorylation and autophagy and apooptosis, mutation in mitochon can lead to genetic diseases (maternally inhereted)
Organelle genomes
cpDNA and mtDNA are compact and withouth histones, multiple copies of genome per organelle,
Gene transfer can happen bettwen
nucleus, mitochon, chloro and all the combinations besides nucleus to chloro
bacterial genome
single covalently circular DNA molecule. not histone proteins but packed. The structure is called a nucleoid.
prokaryotes pack DNA into chromosomes
Plasmids are examples of ecxtra chromosomal DNA
Plasmid DNA
SMall double stranded circular or linear DNA, independednt and self replicating, etrachromosomal
Viral genome
ds or ss, circular or linear, modle for molecular biology,
metagenomics
sequencing of the genome of entire poulation within the virosphere. ORFans (we don’t know what they do yet)
Mammalian DNA viruses
infect mammalian cells and make host machinery for their replication. very diverse form of genome,
