Lecture 17 - The Central Dogma Flashcards
What is the central dogma?
DNA->RNA->Protein
Can you start with protein and go to RNA or DNA?
No
After DNA replication, one strand is the ____ strand and one strand is the _____ strand
Maternal strand and daughter strand
What is at each end of replicated DNA?
Telomeres
What enzyme builds DNA in DNA replication?
DNA polymerase
Is there a leading/lagging strand in the process of DNA replication?
Yes
Is there a leading/lagging strand in the process of transcription?
No
What enzyme builds mRNA in transcription?
RNA polymerase
Where in the cell does transcription take place?
In the nucleus
Each tRNA can bind how many amino acids?
ONLY 1
What does tRNA contain that reads the codon in mRNA?
Anticodon
Explain the ribosomal differences in eukaryotes and prokaryotes (bacteria)
Prokaryotes: 30s+50s=70s
Eukaryotes: 40s+60s=80s
S=sedimentation unit
The bigger the sedimentation unit, the _____ it goes to the bottom of the centrifuge
Faster
How many possible choices are there for codons? How many amino acids are there?
What conclusion can be drawn from the answer to these 2 questions
64 possible choices for codons but there’s only 20 amino acids
=redundancies
What are the 3 steps of translation?
Initiation, elongation, termination
Which recognizes the Shine Dalargno sequence?
-prokaryotes or eukaryotes
Prokaryotes
What is the Shine Dalargno sequence?
Short sequence of mRNA where rRNA can recognize to start translation
mRNA meets the _____ subunit of rRNA, then the _____ subunit
Small then large
What high energy molecule is utilized in the initiation step of translation?
GTP
Name the initiation factor
IF-3
What is the termination step?
Recognition of the stop codon and hydrolysis to release the newly synthesized protein
What is happening in the elongation step of translation?
A longer and longer peptide chain is being created
Is transcription and translation simultaneous in both prokaryotes and eukaryotes? Explain
NO - only simultaneous in bacteria
This cannot happen in eukaryotes because of the presence of the nucleus. Transcription MUST take place in the nucleus and then exported. Bacteria do not have a nucleus
What is the first amino acid added in bacteria(prokaryotes)?
FMET
What is the first amino acid added in eukaryotes?
MET
What does “co translational modification” mean?
The change of one or more amino acids during translation
Give 5 examples of co translational modification
-folding
-deformylation (fmet to met)
-removal of a few N terminal amino acids
-changing conformation of proline
-N glycolysation
What does post translational modification mean?
The change of one or more amino acids AFTER translation
Give 5 examples of post translational modification
-O glycolsylation
-disulfide formation
-splicing
-lipidation
-Ubiquitination
Phosphorylation, acetylation, etc are examples of co or post translational modification?
Post
What would happen if a drug destroyed proteosomes?
Protein with ubiquitine would build up which would cause energy waste and hurt the cell - we would die
A proteosome consists of _____ particles on the ends and a_____ particle in the middle
Regulatory particles on the ends with a core particle in the middle
When an amino acid is added to its corresponding tRNA, ATP is converted to ____ as a ____reaction
AMP as a coupled reaction
