Quiz 3 study guide Flashcards
Which carbon on RNA has the hydroxyl group
2’
What secondary structure does RNA form
hairpin loops
What do ribosomes in RNA do
catylitic properties, store and transmit information
rRNA vs mRNA vs tRNA
rRNA: structural components of ribosome
mRNA: carries genetic code for protein
tRNA: helps incorportate amino acids into polypeptide chain
where is mRNA located
in the nucleus for transcription and then exported to cytoplasm for translation
What is the site of translation
ribosomes
What are ribosomes made of
proteins and nucleic acids
How many ribosomes can be attached to mRNA at one time
many
Which subset of RNA contains an anticodon, and what does the anticodon recognize
tRNA contains an anticodon, it recognizes the codon on mRNA
function of tRNA and common charachteristics
- Binds to amino acid, delivers to ribosome
- Common secondary structure of cloverleaf
which subset of RNA creates a secondary structure of a cloverleaf
tRNA
What is the template for protein synthesis
mRNA
What carries the genetic information to turn DNA into a ribosome
mRNA
what are the 3 primary regions of mRNA
- 5’ untranslated region (start codon)
- protein coding region
- 3’ untranslated region
What are the 3 steps of transcription in bacteria
initiation, elongation, termination
What carries out the required steps of transcription
RNA polymerase (5 subunits)I
In bacteria, what does the one RNA polymerase recognize
the promotor sequence, synthesizes RNA from 5’–>3’ direction
What are the 2 actions RNA polymerase does
read and transcribe
Where does initiation occur
at the promotor region
What are the sequences that are in nearly all bacteria
prinbow box, TATA box
What occurs in elongation
Polymerase unwinds DNA at leading edge of transcription bubble
What stops transcription
Transcription stops after terminator has been transcribed
What are the 2 bacterial terminators
rho independent and rho dependent
What is rho-independent termination
forms loop and hairpin, inverted repeats
What is rho dependent termination
A DNA sequence that produces a pause, unstructured RNA serves as Rho binding site
What is a Rho protein
ATPase, Helicase
What is chromatin modifing prior to transcription
add acetyl group to DNA to allow it to loosen so RNA polymerase can attach
What is the core promotor
location where transcription apparatus binds
What is regulatory promotor
location where trnascriptional activator proteins bind
Which promotor impacts the rate at which transcription is initiated
regulatory promotor
Where do transcriptional activator proteins bind
to more distant sequences
Enhancer vs silencer
Increase rate of transcription vs decrease rate of transcription (at promotor)
What is released from the promotor in elongation
polymerase released from the promotor and TF left behind.
What produces a string of uracils in termination
RNA polymerase 3
Describe the thyroid hormone cascade
TSH releases T4 and T3, effects metabolism, body temperature, etc. Thyroid receptors act as ligands for transcription factors and regulate transcription
What does rifamptin do
bind to bacterial RNA polymerase, distort enzyme conformation and prevent RNA polymerase from working
What transcribes tRNA
RNA polymerase 3
what synthesizes RNA polymerase 2
mRNA
What does beta-thalassemia cause
causes chronic anemia
caused by incorrect splicing of genes
What is the universality of DNA
almost all codons specify the same AA in all organisms
Silent vs missense vs nonsense
- changed base, same amino acid
- changed base, different AA
- changed base, become stop codon
What do trinucleotid repeat expansions produce
neurological symptoms, multiple copies of same AA in a row.
Huntington’s disease characteristics
- Autosomal dominant
-repeat on HTT gene - Gradual onset and progression of dementia/shaking
3M’s: Mood, movement, memory
Myotonic dystrophy characteristics
- autosomal dominant, mutation leads to splicing error
- Muscle weakness, atrophy of faces, cardiac problems
CTG repeat on ch. 19
Fragile X syndrome
-Large ears/testicles, long face, severe intellectual disability (CGG repeat on X chromosome)
Example of insertion/deletion of 3 bases
Chromosome 7
cystic fibrosis- autsomal recessive, CFTR gene, obstruct small airways, obstruct GI fun
Site of translation
ribosomes
