Term
click below
click below
Term
Normal Size Small Size show me how
Transcription
Human Genetics Exam 1
Term | Definition |
---|---|
exome | all of the genomes exons (1.5% of DNA) |
exons | gene encoding region of DNA |
retroviruses | transcribe RNA into DNA |
flu, polio, hepatitis | viruses that use RNA to make proteins |
prions | proteins that replicates themselves |
mRNA | encodes amino acid sequence (size:500-4500 nucleotides) |
rRNA | associates with proteins to form ribosomes (size:100-3000 nucleotides) |
tRNA | transport amino acids to ribosome for protein synthesis (size:75-80 nucleotides) |
snRNA | splice pre-mRNA (splicing) |
miRNA and siRNA | regulate the expression and degradation of mRNA |
snoRNA | covalently modifies rRNA (regulation) |
stems | complementary base pairing (H-bonding) between nucleotides on the same tRNA molecule |
loops | areas of non-complementary nucleotides on the same tRNA molecule |
anticodon | loop area of tRNA that is complementary to an mRNA codon |
amino acid acceptor | the area opposite of the anticodon, strongly bonds to a specific amino acid |
transcription factors | proteins that initiate and regulate transcription of genes;link the genome to the environment |
RNA polymerase | an enzyme that helps to produce mRNA (transcripts); constructs RNA chains using DNA as a template |
promoter | specific sequence that signals that start of a gene (always at the 5' end) |
TATA binding protein | first transcription factor to bind, attracted to the TATA box |
pre-initiation complex made up of: | TATA binding protein, transcription factors, RNA polymerase |
activator | transcription factor that binds enhancer region |
enhancer | region of DNA upstream or downstream of the promoter that binds the activator, needed to start RNA polymerase transcription |
repressor | transcription factor that binds the silencer region |
silencer | region adjacent to enhancer region, prevents RNA polymerase from activating and prevents the gene from being transcribed to mRNA |
terminator sequence: | AATAAA |
in termination (step 3) : | RNA polymerase dissociates, DNA double helix re-anneals |
DNA template strand | sequence is the complement of the growing RNA strand |
DNA coding strand | sequence is identical to the RNA strand (except T becomes U) |
5' cap | backward "G", methyl group added recognition site for translation |
3' tail | 200 "A's", for protein synthesis and stability |
excision of introns | introns cut out, exons are pasted together |
spliceosome | made up of 4 snRPS, cut out introns and glue exons together |
alternative splicing | creates isoforms, allows for more diversity of proteins |
proofing | makes sure mRNA is not too short or long and is the right sequence |
pre-mRNA | a long transcript created by the transcription of protein encoding genes |
spliceosome job: | binds cuts between intron/exon, removes introns, and covalently links exons |
mature mRNA | once pre-mRNA is spliced, capped, edited, and tailed, it becomes this |
constitutive exons | exons that are always found in the mature mRNA in all cell types |
alternative exons | exons that are added to vary the protein product in different cell types |
Rett Syndrome | neuromuscular disorder, mostly affects girls, mutated transcription factor MECP2 on chromosome X |
Treacher Collins Syndrome | RNA polymerase disease, affects development of bones/tissue of face, mutation of rRNA in ribosome formation |