1: The Cell As A Unit Of Health And Disease Flashcards
Pathos =
Logos =
Pathos = SUFFERING
Logos = STUDY
The human genome contains roughly ____________ DNA base pairs
The human genome contains roughly 3.2 billion DNA base pairs
proteins variously function as??
proteins variously function as... >enzymes >structural components >signaling molecules >used to assemble and maintain all of the cells in the body
nuclear genetic material is organized into dispersed transcriptionally active
_________________?
nuclear genetic material is organized into dispersed, transcriptionally active euchromatin or densely packed
nuclear genetic material is organized into dense, transcriptionally inactive
_______________________?
nuclear genetic material is organized into dense transcriptionally inactive heterochromatin
_____________________ can only be visualized by light microscopy during cell division. During _____________, they are organized into paired chromatids connected at centromeres
Chromosomes (as shown) can only be visualized by light microscopy during cell division. During mitosis, they are organized into paired chromatids connected at centromeres
_____________________ act as the locus for the formation of a kinetochore protein complex that regulates chromosome segregation at what phase?
centromeres act as the locus for the formation of a kinetochore protein complex that regulates chromosome segregation at metaphase
The ________repetitive nucleotide sequences that cap the termini of chromatids and permit repeated chromosomal replication without loss of DNA at the chromosome ends.
The telomeres are repetitive nucleotide sequences that cap the termini of chromatids and permit repeated chromosomal replication without loss of DNA at the chromosome ends.
chromatids are organized into…….?
_______
_______
chromatids are organized into short “P” (“petite”) and long “Q” (“next letter in the alphabet”) arms.
________________ are noncoding regions of DNA that initiate gene transcription
Promoters are noncoding regions of DNA that initiate gene transcription
__________________
are regulatory elements that can modulate gene expression over distances of 100 kB or more by looping back onto promoters and recruiting additional factors that are needed to drive the expression of pre-mRNA species.
Enhancers are regulatory elements that can modulate gene expression over distances of 100 kB or more by looping back onto promoters and recruiting additional factors that are needed to drive the expression of pre-mRNA species.
_________ of the human genome that does not encode proteins. It has been known for some time that protein-coding genes in higher organisms are separated by long stretches of DNA whose function has been obscure for many years—sometime denoted as “_______________” of the genome.
98.5% of the human genome that does not encode proteins. It has been known for some time that protein-coding genes in higher organisms are separated by long stretches of DNA whose function has been obscure for many years—sometime denoted as “dark matter” of the genome.
___________________ of the genome that provide the critical “architectural planning.”
noncoding regions of the genome that provide the critical “architectural planning.”
2 regions that provide binding sites for transcription factors?
Promoter and enhancer regions that provide binding sites for transcription factors
___________________________ are subsequently spliced out of the pre-mRNA to produce the definitive message that is translated into protein—without the 3′- and 5′-untranslated regions (UTR).
INTRONIC SEQUENCES are subsequently spliced out of the pre-mRNA to produce the definitive message that is translated into protein—without the 3′- and 5′-untranslated regions (UTR).
“jumping genes”
Mobile genetic elements
E.g. TRANSPOSON
Special structural regions of DNA?
telomeres (chromosome ends)
and
centromeres (chromosome “tethers”)
2 most common DNA variation?
SNPs (Single Nucleotide Polymorphisms)
CNVs (Copy Number Variations)
variants at single nucleotide positions and are almost always biallelic (i.e., only two choices exist at a given site within the population, such as A or T)?
SNPs (Single-Nucleotide Polymorphisms)
more recently identified form of genetic variation consisting of different numbers of large contiguous stretches of DNA from 1000 base pairs to millions of base pairs?
CNV (Copy Number Variations)
heritable changes in gene expression that are not caused by alterations in DNA sequence?
EPIGENETICS
Nucleosomes consist of DNA segments 147 base pairs long that are wrapped around a central core structure of highly conserved low molecular weight proteins called ___________
Nucleosomes consist of DNA segments 147 base pairs long that are wrapped around a central core structure of highly conserved low molecular weight proteins called HISTONES
series of beads joined by short DNA linkers and is generically called ____________
series of beads joined by short DNA linkers and is generically called CHROMATIN
regulates gene expression and thereby dictates cellular identity and activity?
unwounded nuclear chromatin
this carry out more than 70 different histone modifications generically denoted as MARKS
CHROMATIN WRITER COMPLEX
Histone marks are reversible through the activity of ________
CHROMATIN ERASERS
other proteins function as __________, binding histones that bear particular marks and thereby regulating gene expression.
CHROMATIN READERS
methylation of lysine residues in histones may be associated with either transcriptional activation or repression, depending on the histone residue that is “marked”.
HISTONE METHYLATION
_______________________ Lysine residues are acetylated by histone acetyl transferases (HAT), whose modifications tend to open up the chromatin and increase transcription. In turn, these changes can be reversed by histone deacetylases (HDAC), leading to ________________________________
HISTONE ACETYLATION
CHROMATIN CONDENSATION
___________________ Serine residues can be modified by phosphorylation; depending on the specific residue, the DNA may be opened up for transcription or condensed to become inactive.
HISTONE PHOSPHORYLATION
__________________ tightly regulated by methyltransferases, demethylating enzymes, and methylated-DNA-binding proteins.
DNA METHYLATION
which are believed to bind to noncoding regions and control long-range looping of DNA, which is important in regulating the spatial relationships between gene enhancers and promoters that control gene expression.
CHROMATIN ORGANIZING FACTORS
are encoded by genes that are transcribed but not translated.
Micro-RNA and Long Noncoding RNA
____________ do not encode proteins; instead, they function primarily to modulate the translation of target mRNAs into their corresponding proteins.
its transcription produces _________
generates mature single-stranded miRNAs of 21 to 30 nucleotides that are associated with a multiprotein aggregate called _______________
miRNA
primary miRNA
RNA-induced silencing complex (RISC)
All mRNAs contain a so-called __________ in their 3′ untrans-lated region (UTR) that determines the SPECIFICITY of miRNA binding and gene silencing. In this way, the target mRNA is posttranscriptionally silenced.
SEED SEQUENCE
_____________ are short RNA sequences that can be introduced experimentally into cells.
These serves as substrates for Dicer and interact with the RISC complex in a mannaer analogous to endogenous miRNAs.
Small interfering RNAs (siRNAs)
a repressive function involves….
________ which is transcribed from the X chromosome and plays an essential role in physiologic X chromosome inactivation.
itself escapes X inacti-vation, but forms a repressive “cloak” on the X chromo-some from which it is transcribed, resulting in gene silencing.
XIST
where new PROTEIN is SYNTHESIZED
and physically ASSEMBLED in GOLGI APPARATUS
rough ER
