Module 1 Flashcards
Physical Substrate of Genes and Genomes
What part of the gene is responsible for coding?
Exon
What are introns and where are they located?
non-coding DNA within a gene; between 2 exons
What is an untranslated region and how is it transcribed?
It is a non-coding mRNA region that flanks the protein coding sequence
Transcribed from DNA but not translated into proteins
What is splicing?
removal of introns for coding exons
What is alternative splicing
the ability of a gene to produce multiple different mRNA transcripts by combining exons in different ways
What are some examples of possible outcomes of alternative splicing?
cancer, ASD, cell differenitation
What is pre-mRNA?
the transcribed DNA with introns still in it that will be spliced
what is mRNA and what does it do?
it is the spliced premRNA molecule that carries code to ribosomes to make proteins
What is SNP (single nucleotide polymorphism)?
it is the variation in a single DNA base pair
What does gene directionality state?
that strands code in one direction, the coding strand (identical to the RNA) runs 5’ -> 3’
What is the gene promotor?
The DNA site for RNA polymerase binding (CpG islands found here)
**not to be confused with start/stop codons for RNA
What is a codon?
an RNA sequence that codes for a specific amino acid
what is a centromere?
the chromosomal narrowing with kinetochore proteins
what is a telomere?
the end of a chromosome and is rich in repetitive sequences
What is a repeated motif?
a short, recognizable DNA sequence with biological significance
what is a kinetochore?
a small protein in the centromere of a chromosome that is significant to chromosome segregation through its attachment to spindles
When does gene overlapping occur?
when 2 genes are transcribed in the same direction from different frames
what is gene nesting?
is it the presence of multiple other genes within a larger gene that can be in a different location
What does Crick’s central dogma state?
that information can only flow in one direction:
DNA –> RNA –> proteins
what is a sequence element and what process does it play a role in?
it is a functional region within DNA that plays a role in gene expression/regulation (i.e. promoter region)
What is the pre-initiation complex assembly?
it is a multi-protein complex that assembles on the promoter region of a gene to initiate transcription
What is the pre-initiation complex assembly bound to and what binds it?
it is bound to the template strand by TATA binding protein (TBP) to the TFIID of polymerase 2
Identify 3 pioneering scientists who have made significant contributions to core genetics research. Explain their contributions
Karl Von Nageli - Intracellular thread structures (chromosomes)
Mendel - inheritance theory
Watson and Crick - Double helix structure, Crick later gave gene function lecture
Rosalind Franklin provided DNA imagine for Watson and Crick
What aspects make it difficult to delineate the two ends of a gene
Alternative splicing where different combinations of exons become different sequences of RNA
Gene transcription can happen in different directions depending on the orientation of promoter and other core regions
Gene arrangement: there is gene overlapping and nesting on the DNA strand
explain how transcriptional directionality is determined on double-stranded DNA
coding strand runs 5-3
template strand runs 3-5
coding strand is copied
DNA polymerase 2 is activated on promoter regions
