Transcription After Exam 2

Where does Transcription occur in Prokaryotes?

cytoplasm nucleoid region

Where does Transcription occur in Eukaryotes

nucleus

What does Transcription do?

DNA —> mRNA

in Eukaryotes what does Promoter do?

binding region for RNA polymerases

in Eukaryotes what does Open Reading Frame (ORF) do?

gene coding region of DNA template

In Eukaryotes what does Transcription Factor do?

regulation of genes by steroids, hormones that bind/activate a receptor to specific DNA sequence that uses RNA polymerase to transcribe into mRNA

In Eukaryotes what is a new single strand RNA?

single transcript

What is Methyl Cap?

protects 5’ binds ribosomal layer (nuclear pore exported)

What is Polyademine Tail?

protect 3’ translation terminator and ribosome bonding

Does Eukaryotic RNA have intons and exons?

yes

What do Intons do?

staggered and then spliced to another inton and removed by complex spliceosome

What do Exons do?

stagerred between exons and intons and then spliced together by complex spliceosome

For Ribosomes what is the Eukaryotic subunit?

80s (40/60)

For Ribosomes what is the Prokaryotic Subunit?

70s (50/30)

What does mRNA do?

template to determine which AA is needed to make a protein

What does rRNA do?

structure of ribosomal RNA that helps position mRNA

What does tRNA do?

hybrid molecule that folds back over itself into clover shape and attaches AA anticodon

What are the Factors for a Protein?

initialization, elongation, termination

What is the enzyme for Euk transcription?

RNA pol 2

is there modification after enzyme in Euk transcription?

yes cap 5’ tail 3’ splice

What is number of genes/transcripts in euk transcription?

1 gene per transcript monocistronic

What enzyme is in prok Transcription?

other RNA pol

is there modification in prok transcription?

no

What is the number of genes/transcripts in prok transcription?

multiple operon (polycistonic)

Where does translation occur in Eukaryotes?

ribosomes free cytoplasm

when does translation occur in Euk?

well after transcript is made

What AA starts translation in Euk?

AUG methionine

Where does translation occur in prok?

free ribosome in cytoplasm pk

When does translation occur in prok?

right after transcription

What AA starts translation in prok?

modified methionine

Why do we care about translation and transcription bacteria and humans pt1?

target bacterial ribosome w antibiotics erytromycin tetramycins

Why do we care about translation and transcription bacteria and humans pt2?

target RNA pol rifampicin

What do Mutations do?

change DNA sequence instructions or backbone

What do mutagens do?

cause mutations

What is a spontaneous mutation?

mutations or copy errors introduced when nucleic acids are duplicated in DNA rep

What happens in DNA pol for a spontaneous mutation?

Low error rates 1-10million high fidelity

What happens in RNA pol for a spontaneous mutation?

1-1,000 error rates low fidelity

What are some examples of viruses that emerge from errors in RNA poly?

influenza, HIV, SARS, due to Rdrp RNA dependent RNA pol

What are carcinogens?

mutate genes involved with cell division cancer causing

What is a physical mutagen?

radiation, ionizing x-ray, gamma, non-ionizing UV

What is a Chemical mutagen?

formaldehyde or nitrates

What is a Biological Mutagen?

viruses bacteria

What is a single point mutation?

substitution of one nitrogenous base

What is a Silent mutation?

DNA change nitrogenous base but not AA

What is a nonsense mutation?

single DNA changes from regular codon to stop codon

What is a Missense Mutation

Change codon to another codon

What is an Insertion/Deletion Mutation?

large change of 3 bases caused by frameshift and radiation

What is a frameshift?

mutation changes reading frame and translation of the mRNA sequence affects resulting protein

What are Pyrimidine Dimer made of ?

Thymine, Cytosine, excess phosphodeister linkages

How can pyrimidine dimers be mutated?

UV mutates dimer causing multiple phosphodiester linkages

Can we fix Thymine Dimers?

Yes Nucleotide excision repair NER

What does NER do?

enzyme meant to fix mutations in genome

What is Xerodemia Pigmentosum?

help NER unwind genome replace and seal back together helix strands

Are viruses Cellular?

acellular

What is the size of most viruses?

nanometers ex 30nm polo

What is the genome structure for Viruses?

RNA circular or DNA multiple not both

Can a virus reproduce with another virus?

No needs host cell to reproduce obligate intracellular parasite

What does Naked Virus mean?

nucleic acid + protein shell (capsid)

Do Viruses synthesize or make Energy?

Uses host cells metabolism to make ATP and ribosomes to make proteins

Where is a Virus active?

inside the cell

Where is a virus inactive?

Outside the cell

What are some Example Viruses in DNA specific?

Varicella opster, Hep B, HPV

What are the 3 categories for RNA Viruses?

positive, negative, retro

What are some examples for negative RNA viruses?

influenza, SARS-COV-2, Measles

What are some examples from Rertro Viruses (RNA)?

HIV, HTLV