TRUE or FALSE splicing regulation increase number of gene
TRUE splicing regulation allows for more genes than DNA contains
what separates differentiated cells
- different protein expression/ activity
- requires different patterns of gene expression to allow them to perform their specialised function
what proteins are common across all specialised and unspecialised cells
- housekeeping proteins
= histones, RNA poly, beta-actin, tubulin, glycolytic enzymes
(encoded by housekeeping genes)
TRUE or FLASE - differentiation is a highly controlled step
TRUE differentiation and production of proteins are highly controlled steps
what proteins are only expressed in specialised cells
specialised proteins are exclusively expressed in specialised cells
(these are not essential for cell viability)
what are the two states the genes can be expressed
constitutively expressed - always on
conditionally expressed - inducible
what is the first control step for regulating gene expression
transcriptional control
TRUE or FALSE - RNA levels are the same of protein levels?
FALSE - RNA level does not necessarily mean protein levels are they have different expressions/abundances»»»>
what are the co-transcriptional processes
Co-transcription process are the molecular events that occur while RNA is being transcribed from DNA, rather than after transcription finishes. They tightly coordinate with RNA polymerase to ensure efficient, accurate gene expression.
why have introns in DNA
- exons often encode discrete protein domains
- important for evolution
- allows for alternative mRNA splicing
what are the intron-exon boundaries
AG-GU regions however also need a splicing sequence to cause the splicing to occur
features of the intron
5’ donor splice site
3’ acceptor splice site
polypyrimidine tract(pYn)
branch point nucleotides
what are snRNPs
small nuclear ribonucleoproteins (snRNPs) are RNA protein complexes that recognise splice sites and form the core of the spliceosomes, which removes introns from pre-mRNA
structure of snRNP
subunits (U1 to U6)
U1 & U2 snRNP recognise 5’ donor and branch point initiating mRNA
what do the U1 and U2 snRNPs recognize during mRNA splicing
the 5’ donor site and branch point on the intron
what is the role of snRNPs U1-U6 in the mRNA splicing
they form large complexes that initiate and carry out splicing by recognizing splice sites and assembling the spliceosome
what strucutre forms during intron removal and what happens to it
a lariat structure forms and is later degraded
what is the post-splicing complex called?
the P complex
what do hnRNPs bind to and what is their function in splicing
they bind to exons and poly-A-regions to regulate spliceosome formation and inhibit splicing
what is the role of RNA binding protein (RNBPs) in splicing
they regulate splicing and may affect transcription elongation via DNA polymerase 1
what are four modes of alternative splicing
alternative promoter selection
alternative cleavage site selection
intron retention
exon cassette inclusion
how does alternative splicing affect cellular function
it allows a single gene to produce multiple protein isoforms influencing cell behaviour and function
how does alternative splicing of VEGF-A affect its function
it alters the protein domain, changing how VEG-A binds to growth factor
what regions in the exon control regulation of mRNA splicing
- serine/arginine-rich splicing factors = enhancers of splicing
- hnRNP = bind to inhibit splicing
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Background a-level revision0
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genome and DNA replication50
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transcription19
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translation27
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chromatin and epigenetics34
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Biological Membranes35
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membrane transport22
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fluid compartments and osmosis18
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glycolysis and glucose metabolism30
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citric acid cycle and oxidative phosphorlyation34
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gene expression24
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gene expression 216
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genetics mechanisms and mutations15
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genetics single gene disorders25
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meiosis and chromosomal disorders19
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evolution and biodiversity22
