Term
| In what direction is the protein synthesis on polysomes? |
|
Definition
| Polysomes synthesize N terminal first. |
|
|
Term
| At what end is the start site on the DNA template for polysomes? |
|
Definition
| The start site is at the 5' end of the mRNA template. |
|
|
Term
| What is a polysome consist of? |
|
Definition
| Polysomes consist of multiple ribosomes subunits translating an mRNA. |
|
|
Term
| What is the Cental Dogma of protien synthesis? |
|
Definition
| The Central Dogma states that the movement of information is unidirectional in that it flows from DNA to RNA to Protein only. |
|
|
Term
| What is the triplet code for starting transcription and what amino acid does it code for? |
|
Definition
| AUG is the start codon for transcription and it codes for Methionine. |
|
|
Term
| What are the stop triplet codon for protein synthesis? |
|
Definition
| UAG, UAA, & UGA are the stop codon for protein synthesis. |
|
|
Term
| What is the triplet codon for Glutamine? |
|
Definition
| GAG is the codon for the Glutamine. |
|
|
Term
| What is the triplet codon for Val and what is its implication in hemoglobin? |
|
Definition
| Valine's codon is GUG, and it is implicated in the structurally compromised hemoglobin causing sickle cell; this is classic point mutation of normal codon of GAG which codes for Glutamine. |
|
|
Term
| What type of point mutation causes Hemoglobin S where the Beta chain is mutated? |
|
Definition
| Mutation of Beta chain in hemoglobin S is caused by missense mutations. |
|
|
Term
| Shortening of DNA is indicative of which type of point mutation? |
|
Definition
| Nonsense point mutation & frameshift deletion mutation shortens the DNA chain. |
|
|
Term
| DNA elongation is caused by what type of mutation? |
|
Definition
| Suppresor point mutation & Frameshift insertion causes chain elongation. |
|
|
Term
| What are the components of translation machinery? |
|
Definition
| The translational components consists of Ribosomes, mRNA, tRNA, Amino acids, Enzymes, and Energy. |
|
|
Term
| The translational components consists of Ribosomes, mRNA, tRNA, Amino acids, Enzymes, and Energy. |
|
Definition
| The ribosome is composed of Large subunit (consisting of central protuberance) and small subunit. |
|
|
Term
50S and 30S subunits is indicative of what type of ribosome?
|
|
Definition
| Prokaryotic ribosome consists of 50S and 30S subunits. |
|
|
Term
| 60S and 40S subunits are from what type of ribosomes? |
|
Definition
| Eukaryotic ribosomes compose the 60 & 40 subunits. |
|
|
Term
| Eukaryotic translation consist of what genomic parts? |
|
Definition
| 5' cap, 5'UTR, 3' UTR, only 1 coding region, and 3' poly A of 150 nucleotides is typical of Eukaryotic translation. |
|
|
Term
| Prokaryotic translation is typified by what? |
|
Definition
| Polycistronic or more than one ORF/coding region characteristic of prokaryotic translation. |
|
|
Term
| Tranlational adaptor can be described as? |
|
Definition
| tRNA, consisting of 3 Loops, loop 2 containing anticodon sequence, and 3' OH amino acid accepting end. |
|
|
Term
| What is the first step in the formation of aminoacyl-tRNA? |
|
Definition
| The amino acid is 1st activated by reacting with ATP by amino acid synthetase. |
|
|
Term
| What is the second step of aminoacyl-tRNA formation? |
|
Definition
| The activated amino acid transferred from aminoacyl-AMP to tRNA. |
|
|
Term
| What and Where is the wobble position on the codon and anticodon machinery? |
|
Definition
| The wobble postion is the codon region where flexability is allowed in amino acid coding, it is at postion 1 on the anti-codon region and on position 3 on the mRNA. |
|
|
Term
What two enzyme are vital for the fidelity of protein synthesis?
|
|
Definition
Aminoacyl tRNA synthetase is important for activating amino acid and tranfering it to the 3'OH end.
|
|
|
Term
| What are the functions and codons for methionine tRNAs? |
|
Definition
| Methionine tRNAs serve as AUG initiation codon this dubbed N-formyl / F-Met in bacteria, and the other tRNA serve in the internal Met codon. |
|
|
Term
| What are the stages of translation? |
|
Definition
| 1st-charging of tRNA, 2nd-Initiation, 3rd-Elongaiton, 4th-Termination, 5th-modification. |
|
|
Term
| What stage of translation where both eukaryotes and prokaryotes share the same enzyme? |
|
Definition
| The first stage of both organisms use Aminoacyl-tRNA synthetase to charge tRNA. |
|
|
Term
| Cap dependent scanning is seen in which organism and how is it used? |
|
Definition
| Cap-dependent scanning is used by 40 S ribosomes of Eukaryotes to find their initation sites. |
|
|
Term
| What is the synanomous structure in the prokaryote to cap dependent scanning? |
|
Definition
| The Shine-Delgarno box is what 30 S prokaryotic ribosomes use to find their initiation site for translation. |
|
|
Term
| IRES differs from Cap dependent how? |
|
Definition
| Internal ribosome entry site does not use a 5' cap to find scan for AUG, IRES allows for translation initiation in the middle of a messenger RNA. |
|
|
Term
| What class of pharmaceuticals target prokaryotic 30s ribosomes? |
|
Definition
| Aminoglycosides are drugs that target the 30s ribosome causing miscoding during elongation, streptomycin is an example of this drug but it inhibits initiation. |
|
|
Term
| In translation, what steps make up the elongation phase? |
|
Definition
The 1st step of Elongation is Amino Acid-tRNA binding, 2nd=Peptidyl Transfer, and 3rd =Translocation.
|
|
|
Term
What drug class inhibits binding of AA-tRNA to A site?
|
|
Definition
| Tetracyclines inhibits A site binding of AA-tRNA of 30 s ribosome. |
|
|
Term
| In elongation what drug inhibits the peptidyl transferase? |
|
Definition
| Chloramphenicol targets 50s inhibiting peptidyl transferase. |
|
|
Term
In elongation, what drug inhibits translocation?
|
|
Definition
Translocation is inhibited by Erythromycin/Clindamycin which targets 50s inhibiting translocation.
|
|
|
Term
| Toxins to Eukarotic 60s ribosomes is seen by what toxin? |
|
Definition
| Ricin's A depurinates 28s rRNA at A residue, at 60s inhibits binding of AA-tRNA to A site. |
|
|
Term
| How is Diphtheria toxin cause toxicity in eukaryotes? |
|
Definition
| Diphtheria toxin targets eEF2 inhibiting translocation. |
|
|
Term
| What drugs is toxic to prokaryotes and eukaryotes during elongation phase? |
|
Definition
| Puromycin targets both 50s & 60s ribosomes causing premature release of nascent polypeptide. |
|
|
Term
| Puromycin imitates which genomic structure & what is its mechanism of toxicity? |
|
Definition
| Tyrosinyl-tRNA is the anologue that Puromycin imitates causing premature release of nascent polypeptide. |
|
|
Term
| What does termination phase of protein translation consist of? |
|
Definition
Termination consists of termination and release of polypeptide.
|
|
|
Term
| How does termination begin? |
|
Definition
Termination is produced by reading termination sequences UAG, UAA, or UGA, 2nd-release factor binds to a stop codon releasing the polypeptide, 3rd-complex dissociates.
|
|
|
Term
| What is the energetic cost of tRNA charging? |
|
Definition
| Amino acid charging of tRNA cost 2ATP. |
|
|
Term
| How does Initiation energetics compare with the other phases of translation? |
|
Definition
| Initiation it the most costly of all; several ATP for unwinding & scanning, and 1GTP for Met-tRNA binding. |
|
|
Term
How much does it cost to produces 1 amino acid compared to an average protein?
|
|
Definition
| The cost for 1AA is about 4ATPs, however 1 protein costs 1200 ATPs. |
|
|
Term
| IRE-BP bound to IRE indicates what about [Fe+2]? |
|
Definition
| This indicates that ferritin in not needed thus intracellular [Fe+2] is low. |
|
|
Term
Early onset of cataract syndrome and serum ferritin is indicative of what diagnosis?
|
|
Definition
| Hyperferritinemia is the cause of ferritin release into serum, and cataract formation, the cause of these is IRE mutation where ferritin synthesis is de-repressed. |
|
|
Term
Protein synthesis is down-regulated at the level of the supply of initiator Met-tRNAi how?
|
|
Definition
| Met-tRNAi is inhibited thus halting protein synthesis by phosphorylating elF2 through kinase activity. |
|
|
Term
| When is protein synthesis halted by the down regulation of initiator of Met-tRNAi? |
|
Definition
| Inhibition of protein synthesis via elF2 kinases occurs via HRI in reticulocytes w/o heme, PKR in interferon plus virus infection, ER stress via PERK, and during amino acid starvation via GCN4. |
|
|
Term
| What does elF2 do and what disease is caused by its mutation? |
|
Definition
| elF2 supplies intiator Met-tRNAi to the 40s subunit leading down the protein synthesis pathway, its mutation leads to Vanishing White Matter (VWM) typified by neurologic deterioration. |
|
|
Term
| GDP is exchanged for GTP is what process of protein synthesis? |
|
Definition
| GDP to GTP exchange occurs in the initiation and elongation of amino acid synthesis. |
|
|
Term
| When ER stress kinase PERK is mutated what diagnosis results? |
|
Definition
| Mutation of PERK kinase of the ER leads to Wolcott-Rallison syndrome which is characterized by IDDM1 & Growth defects & bone dysplasia. |
|
|
Term
| Kinase activity is shown to inhibit protein synthesis, however kinase activity up-regulates mRNA binding where? |
|
Definition
| Kinase cascade induced by GF, mitogens, hormones, and cytokines cause phosphorylation of elF4E-4E-BP complex causing the release of 4E-BP, elF4E is phosphorylated and binds to 5'cap and A&G complex leading to scanning and protein synthesis. |
|
|
Term
| What is the shape of Eukaryotic mRNA? |
|
Definition
| The functional shape of Eukaryotic mRNA is circular by elF4E, G and poly A Binding protein. |
|
|
Term
| Elongation is regulated by which factor? |
|
Definition
| SRP recognizes signal peptide and receptor, controls elongation, and targets ER. |
|
|
Term
| True or false, transcription & translation is coupled in Eukaryotic nucleus? |
|
Definition
| False Eukaryotic transcription & translation is seperated, Prokaryotic is not. |
|
|
Term
| In which organism is Met-tRNAi binding first then mRNA binding? |
|
Definition
This occurs only in Eukaryotes, prokaryotes events occur in the opposite direction.
|
|
|
