Protein- Reynolds Flashcards
1
Q
Protein synthesis
A
mRNA is translated into aa sequence
2
Q
mRNA sequence corresponds to the non-template strand of DNA except
A
U in place of T in RNA
3
Q
Codons
A
- triplet nucleotides bind to anticodon
- 5’ to 3’
- each codon codes for one specific aa
4
Q
degenerate Codon
A
Multiple ways to code for the same aa
5
Q
Start codon
stop codon
A
- Start codon
- AUG
- corresponds to N-terminus of the protein
- Stop codon
- UAA, UAG, UGA
- corresponds to C-terminus of the protein
6
Q
Reading Frames
A
- mRNA= 3 potential reading frames
- DNA= 6 potential reading frames (3 each strand)
7
Q
Use aa table
A
first letter vertical
second letter horizontal
third letter find in the box
8
Q
Splice site mutation
A
alter the way in which introns are removed
9
Q
Requirements for protein synthesis
7
A
- aa
- tRNAs
- aminoacyl-tRNA synthetases
- mRNA
- Ribosomes
- Protein factors
- ATP and GTP
10
Q
Steps in protein synthesis
5
A
- Activation of amino acids
- Initiation
- Elongation
- Termination
- Folding and posttranslational processing
11
Q
tRNA structure
A
- reads the codons
- stucture
- acceptor stem→ ACC
- anticodon→ tRNA bp w/ codon in mRNA antiparallely
- unique nucleotide bases
12
Q
Wobble
A
- allows one anticodon to base pair with several different codons
- If tRNA anticodon recognized only one codon, cells would have a different tRNA for each codon (which they do not)
- First 2 bases of codon form strong H-bonding with anticodon
- Codons that differ in the first two bases require different tRNAs
13
Q
Ribosome
A
- mainly rRNA (65%) and some protein
- Different size subunits
- most RNA is rRNA (80%)→ tRNA (15%)→mRNA (5%)
14
Q
AA activation/tRNA charging
A
Aminoacyl-tRNA synthetases
- aa activation/charge to cognate tRNA
- specific for one aa and one or more tRNAs
15
Q
Initiation
SD
A
Shine-Dalgarno sequence (SD)
- only in prok
- euk has 5’ cap
- purine rich sequence upstream of AUG
