Term
Alway write 5' to 3'
give the pair to
5' TAGGC 3' |
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Definition
3' ATCCG 5'
*answer 5' GCCTA 3' |
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Term
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Definition
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Term
| Describe what occurs how transcription begins and the name of it |
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Definition
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Term
| Describe the 2nd step of transcription and the name |
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Definition
Elongation
RNA plymerase makes RNA
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Term
| Describe the 3rd/ last step of transcription |
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Definition
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Term
| Describe 3 steps to Transcription |
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Definition
| Initiation, Elongation, Termination |
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Term
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Definition
No internal membrane PRO
Trans and Transcript occur at diff places EUK |
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Term
| What is the final product of RNA processing? |
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Definition
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Term
| What/where are the 3 main modifications made in RNA processing? |
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Definition
Beginning-5' cap addition
Middle-intron splicing
End-3' poly-adenylation |
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Term
| What happens to the Pre-mRNA prior to its export in RNA processing? Where does it get sent to? |
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Definition
| It is modified before it is sent to thte nucleus |
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Term
| What happens at the beginning of mRNA processing? |
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Definition
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Term
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Definition
| Addition of mthylated G (not encoded by gene) to 5' end of RNA |
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Term
| What occurs at the end of mTNA processing? |
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Definition
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Term
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Definition
| Addition of many (>100) As (not encoded by gene) to the 3’ end |
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Term
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Definition
Removal of stretches of sequence (‘introns’) that are encoded by
the gene but do not appear in the mature mRNA (those that remain
are ‘exons’) |
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Term
| What are the 3 main processes that occur during mRNA processing? |
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Definition
Capping
Polyadenylation
Splicing |
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Term
| Decribe the process of RNA splicing |
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Definition
Carried out by the splicosome, a ribonucleoprotein (protein and RNA together, like telomerase)
Uses sequence-specific base pairing to recognize introns then removes them
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Term
| What is RNA processing Universal in? |
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Definition
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Term
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Definition
The zone(enzymatic complex) that carries out spicing (ribonucleoprotein)
made of individual units
has one or more RNA associated with it |
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Term
| Why is capping and polyadenylation important? |
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Definition
Protects mRNA from exonucleases ( enzymes that chew up RNA from the ends)
signals for export from nucleus
Necesary for appropriate translation |
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Term
| Whys is splicing important? |
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Definition
it produces variability
Alternative splicing can give more than one proteinfrom a single gene |
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Term
| What is the Genetic code? |
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Definition
- 3 consecutive bases in which information in RNA is converted to information in protein
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Term
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Definition
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Term
| What are the stop codons? |
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Definition
UAA, UAG, UGA
These have no coressponding amino acid |
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Term
| Can some amino acids have more than one codon? |
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Definition
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Term
| What is the amino acid that has only one codon? |
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Definition
| Start or Met = AUG-methionine |
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Term
| What does each protein start with? |
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Definition
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Term
| What does each codon direct? |
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Definition
| Directs the incorporation of a specific amino acid |
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Term
| What are 3 RNA mediated processes? |
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Definition
Translatio
Messenger RNA (mRNA)- Information source
Transfer RNA (tRNA)- Bridge to amino acids
Ribosomal RNA (rRNA)- Enzymatic function within
ribosome |
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Term
| What are the three forms of RNAs? |
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Definition
messenger (mRNA)
transfer (tRNA)
Ribosomal (rRNA) |
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Term
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Definition
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Term
| what does shape does tRNA form? |
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Definition
clover leaf structre when envisioned in 2D
L-shaped in 3D |
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Term
| What are the most important parts of tRNA? |
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Definition
The two ends
anticodon
amino acid attachment site at 3' end |
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Term
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Definition
| 3 bases that forms hydrogen bonds with the codon on mRNA |
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Term
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Definition
Enzymes bind to each specific amino acid and tRNA and link them togerther
Are specific tRNAs for each amino acid
There is a specific enzyme for each amino acid/tRNA combination |
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Term
| What deos tRNA need for energy? |
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Definition
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Term
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Definition
non-membrane-bound organelle-visible by TEM
carries out protein synthesis
Large ribonucleoprotein
Made up of two septarable subunits (large and small) |
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Term
| What is a ribonucleoprotein? |
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Definition
| DNA and protein-most is ribosomal RNA (rNA), plays structureal and catalytic roles, protein plays structural role |
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Term
| What are the three binding sites of the ribosome? |
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Definition
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Term
| What occurs at the A site? |
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Definition
| Aminoacyl (where new aa-tRNA enters) |
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Term
| What occurs at the P-site? |
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Definition
| Peptidyl (where growing peptide chain linked to tRNA is bound) |
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Term
| What occurs at the E-site? |
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Definition
| Exit ( where tRNA goes after releasing peptide, then leaves) |
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Term
| How does each site in the ribosome align? |
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Definition
With a single mRNA codon
tRNAs and mRNA codons eter the ribosome at A-site, then move to P-site then E-site, from which they exit (A>P>E) |
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Term
| What are the three steps of Translation? |
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Definition
Initiation
Elongation
Termination |
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Term
| What occurs in The first step of Translation? |
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Definition
Initiation
◦ Ribosome small subunit binds mRNA
- (at 5’ cap in Eukaryotes)
- (at specific binding sequence in bacteria)
◦ Lines up Start codon at P-site
◦ Initiator tRNA binds to start codon
◦ Large subunit joins complex
- Initiator tRNA in P site
- Requires energy (GTP) |
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Term
| How does splicing allow variability? |
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Definition
Evolutionary implications – recombining domains
Proteins that carry out multiple functions frequently have the
parts carrying out these functions located on different
separable ‘domains’
Exons frequently encode
distinct functional domains
within a protein
This allows modular protein
construction
By alternative splicing you can add in
or leave out protein domains, giving
you multiple possible protein products
from the same gene |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| Enzymatic function within ribosome |
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Term
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Definition
| tRNA synthetase specifically links tyrosine and tRNA^tyr |
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Term
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Definition
| tRNA synthetase links methionine and and tRNA^met |
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Term
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Definition
| a nucleoside triphosphate used by cells to store energy |
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Term
| What occurs in the second step of Translation? |
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Definition
Codon recognition - Aminoacyl-tRNA loaded into A-site
Peptide bond formation-Peptide bond is formed between peptide (short amino acid chain) on tRNA in P-site and aminoacyl tRNA in A-site
-Briefly transfers growing peptide to the A-site rRNA
Translocation-mRNA/rTNA complex is moved within the ribosome to the next site |
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Term
| What is codon recognition? |
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Definition
Occurs in elongation of translation
◦ Aminoacyl-tRNA loaded into
A-site
tRNA anticodon base pairs with
mRNA codon
Correct tRNA selected by
sampling
Protein factor that loads tRNA
requires energy
GTP |
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Term
| What is peptide bond formation? |
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Definition
Occurs in elongation of translation
Peptide bond is formed between peptide (short amino acid chain) on tRNA in P-site and aminoacyl tRNA
in A-site
◦ Breifly transfers growing peptide to
the A-site tRNA |
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Term
| What occurs during translocation? |
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Definition
RNA/tRNA complex is moved within the
ribosome to the next site
Requires energy (GTP)
tRNA in A-site, with peptide,
ends up in P-site
Empty tRNA in P-site ends up
in E-site
Free to exit |
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Term
| What happens after the three steps of elongation have occurred? |
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Definition
A new codon has been lined up in A-site, ready for a new tRNA to repeat the cycle
Repeat cycle until a stop codon is reached |
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Term
| Describe the third process in translation |
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Definition
Termination
◦ protein Release Factors (RFs) bind to stop codon in
A-site
◦ Hydrolyzes bond connecting peptide to P-site tRNA
Releases completed protein from ribosome
◦ Ribosome dissociates, releasing mRNA
Requires energy (GTP) |
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Term
| What are polyribosomes/polysomes? |
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Definition
◦ Multiple ribosomes can translate the same mRNA at
once
You don’t have to wait for one to finish before the next
starts - as soon as one clears the start codon, another can
load on and immediately start
Allows rapid translation |
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Term
| How transcription and translation in prokaryotes? |
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Definition
They are linked,but are not segregated in time and space
Multiple RNA polymerases can be transcribing the same gene at once
Polyribosomes can form on each mRNA mRNA
This results in a whole lot of protein being made from the same gene, all at once |
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