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50 Cards in this Set
- Front
- Back
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Template strand |
The SS of DNA that is anti parallel to mRNA and coding strand |
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5’—> 3’ |
N-terminus—> C-terminus |
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mRNA carries info from DNA to _________ and is transcribed by which enzyme? |
Ribosomes; RNA polymerase |
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tRNA role |
Convert nucleic acid language to amino acid/peptide language; has anticodon that pairs with an mRNA |
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rRNA role and location |
Made in the nucleolus; aids in protein assembly and functions as a ribozyme |
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Ribozyme |
Enzyme made up of RNA molecules |
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Codons contain |
3 bases. |
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Start codon |
AUG (methionine) |
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STOP codons |
UAA UGA UAG |
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Which amino acid isn’t recognized by tRNA |
Methionine |
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Silent mutations |
Mutations that affect the wobble position and don’t change the amino acid it codes for |
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Wobble position |
Third position in a coffin sequence |
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Degeneracy |
More than one codon can specify a single amino acid |
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Missense mutations |
An amino acid changes due to one nucleotide mutating |
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Nonsense mutation |
Premature stop codon (truncation) |
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Frameshift mutation |
2 or more nucleotides added or deleted from a sequence |
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How does DNA leave the nucleus? |
It doesn’t. It uses mRNA to survive in the cytoplasm |
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Promoters |
Specialized DNA regions used as binding sites |
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TATA box |
Promoter region that RNA polymerase typically binds |
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Transcription factors |
Help RNA polymerase bind to promoters |
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Does RNA polymerase require a primer? |
No |
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Does RNA polymerase proofread it’s strand before being transcribed? |
No. Only DNA polymerase proofreads |
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Splicing |
Removal of non coding introns and ligating coding Exons together |
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Spliceosomes |
snRNA and snRNPs recognize the 5’ and 3’ ends of introns. They excise the intron and then degrade it |
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5’ cap |
Part of mRNA that protects it from degradation in the cytoplasm Facilitated transport to cytoplasm Protects from Exonuclease Help ribosome attach your site if translation
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3’ poly A tail |
Made of adenosine; linger the tail, longer it takes to degrade |
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Where do tRNA and mRNA bind? |
Ribosomes |
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What’re the 3 steps in translation? |
Initiation Elongation Termination |
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Initiation |
Charged initiator tRNA binds to AUG (methionine) within the P site |
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Elongation |
3 steps: 1) A site- next amino acid added to the chain 2) P site holds tRNA that carries peptide chain and methionine binds to start chain 3) E site- inactivated tRNA pauses then exits |
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Termination |
Stop codon is added along with water to hinder growth |
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RNA polymerase is a __________ kinase |
Dependent kinase |
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Transcription progresses at a rate of __________ per second in eukaryotes |
40 nucleotides |
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What releases transcriptional machinery? |
RNA pol by phosphorylation |
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In eukaryotes, RNA pol 2 makes |
Poly A sequence |
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3 post transcriptional modification step? |
5’ capping Splicing 3’ poly A tail |
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De novo |
No primer |
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Do restriction enzymes work on RNA, DNA, or both? |
Only RNA |
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What’re restriction enzymes? |
Type of endonuclease that recognizes sequence that needs extraction |
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How is cDNA made? |
Via reverse transcriptase from mRNA |
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cDNA lacks what? |
Introns |
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What’s the branching point of an intron? |
Adenine |
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What’s the branching point of an intron? |
Adenine |
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How’s the lariat loop formed? |
A spliceosome recognizes the 5’ splice site of the intron. It is then lysed and interacts with the 2’ hydroxyl of Adenine. The Exons are then ligated together |
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Can nucleotide changes effect splice sites? If so, in what ways? |
It can destroy splice sites, causing exon skipping. Others can cause cryptic (pseudo) splice sites, making new Exons. |
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Which U is responsible for attaching the ribosome to the TATA box? |
U2 |
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Which U is responsible for attaching the ribosome to the TATA box? |
U2 |
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U6 |
A ribozyme that Cleaves the lariat loop from the exon |
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The function of U4 |
To regulate/inhibit the function of U6. If not, U6 will continue to cut |
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What is the 5’ cap made of? |
7-methylguanosine |
