eukaryotic gene structure Flashcards
what is a gene?
a segment of DNA containing instructions for making a specific molecule
product may be a protein product or a non coding RNA molecule
what are examples of ncRNA?
transfer RNA
ribosomal RNA
what are alleles?
alternative forms of the same gene
what is a structural gene?
code for proteins that perform a wide range of functions, including structural proteins and enzymes
what is a regulatory gene?
code for proteins or RNA that affect transcription or translation of target genes, either positively negatively
what are the distal enhancer elements?
short sequences similar to promoter regions
cis acting
activators bind to this site
why are distal enhancer elements required?
for maximal gene expression
what does the proximal control elements consist of?
GC box
CAAT box
what are the proximal control elements?
distinct pattern of sequences
cis acting
binding sites for transcription factors
why are proximal control elements important?
for transcription regulation
what is the core promoter?
binding site for TATA binding protein and association factor
recruitment of RNA polymerase
determines transcription start site
indicates direction of transcription and which strand is read
what are SNP’s?
single nucleotide polymorphisms
what is an anonymous SNP?
has no effect on gene function
what is a non-coding SNP?
outside of the gene
types of coding SNP’s
synonymous SNP’s, encode for the same amino acid as original
non-synonymous SNP, change amino acid sequence
what are CNV’s?
copy number variations
common in repetitive sequences
what is a mutation?
a change in DNA sequence or rearrangement of genetic material
what are point mutations?
substitution of a single base
what is a silent point mutation?
has no effect on the protein sequence
what is a missense point mutation?
results in amino acid substitution
what is a nonsense point mutation?
substitutes a stop codon for an amino acid
what is a frameshift mutation?
insertion or deletion of one or more bases
what is an operon?
a cluster of genes with related function under control of a single promoter
