_Luna_

Forget the first post! mRNA binds oneself to the 30S ribosomal unit: a) in a complex with GTP a) first after it has been attached to initiating factors Poly-a-tail: a) Are in every eukaryote mRNA. b) Exists if the transcript has a sequence which specify polyA on the 3’ end. I didn't think it was in every single eykaryote mRNA, so I guess the b is correct Stop codon: Are recognized by equal terminating factors Will always sit on the anti-codon bow. Are recognize by own tRNA when these binds to the A seat Are different in mitochondria’s and in cytoplasm. Doesn’t exist in tRNA Again I believe the answer is doesn't exist in rRNA, but I think I read somewhere that in mitochondrias one of the stopcodon actually codes for thryptofan? Transcription factors binds to: a. A intact DNA double helix, and promotes the binding of RNA Polymerase b. Simple stranded DNA c. Special seats where DNA helix has been melted d. Histones a or b? A alfahelix is destabilized by: a. Two Lys residues near amino terminus in alfa helix b. Interactions between to hydrophobic Val residues in neighbouring positions. c. Interactions between to Asp and Arg residues in neighbour positions. Lys has a charge + while Val is 0, so I am thinking a The advantage by measuring the initial reaction rate V0 at the beginning of the reaction is: a. The [ES] is measured precisely b. The changes in are insignificant and can be looked on as a constant c. The changes in [Km] are insignificant and [Km] can be looked on as a constant. Here I am a bit confused, maybe a or b. E.coli DNA pol III: a. Represents over 90% av DNA polymerase activity in E.coli? b. Is the most important DNA polymerase in chromosomal DNA replication? I think it's pol I that represents 90% and therefor I'll choose b When a protein is completely hydrolyzed will the further analyse: a. Only detect aminoacids in S conformation b. Often detect other molecules besides aminoacids c. Never detect more than 20 standard aminoacids d. Never detect fewer than 20 standard aminoacids e. Only detect the 20 standard aminoacids This is a silly question because they don't mention what kind of protein where are looking on. Does anyone have some thoughts about this one? Which of the following statements of E.coli RNA polymerase is wrong? a. RNA made by this enzyme is complementary to the DNA template b. The coreenzyme binds to the promoter, but will never initiate the synthesis without a sigma factor. RNA will never be completyly complementary to the DNA because you change T with U.

A ribozyme is: a) a protein in 30S ribosome unit. b) a RNA that hydrates proteins. c) a protein that cleaves RNA d) a RNA that splits oneself and then glues the pieces together in a new way. mRNA binds oneself to the 30S ribosomal unit: a) in a complex with GTP b) and is then modified with a cap c) together with elongating factors d) first after it has been attached to initiating factors e) none of the above. Poly-a-tail: a) Are in every eukaryote mRNA. b) Are out on the end of every gene transcript c) Exists if the transcript has a sequence which specify polyA on the 3’ end. d) Exist in the end of every gene e) Exists only in prokaryote mRNA Stop codon: a) Are recognized by equal terminating factors b) Will always sit on the anti-codon bow. c) Are recognize by own tRNA when these binds to the A seat d) Are different in mitochondria’s and in cytoplasm. e) Doesn’t exist in tRNA Transcription factors binds to: a) A intact DNA double helix, and promotes the binding of RNA Polymerase b) RNA polymerase c) Single stranded DNA d) Special seats where DNA helix has been melted e) Histones The difference between sigma factor and transcription factor is that: a) Sigmafactors are found in bacterias while transcription factors dominates in eukaryote b) Sigma factors binds to DNA while transcriptionfactors bind to repressors. c) They are included in respective eukaryote and prokaryote: Does anyone of you have any comment? I am going on a lecture now, but I'll be back to comment some more.

Hey, I have some multiple choice questions that's bother me. I'll try translating them hoping someone could give me an answear. 1. Hydrophobic interaction in protein is giving important stabilization contributions a) to proteins secundary- and tertiarystructure. b) just to the orientation of polar amino acids c) to the proteins primarystructure d) after every possible hydrogenbonding are formed e) only in hydrophobic fases I am here guessing a or d, but I am very uncertain. 2. The structural membraneproteins are characterized in case of that they a) don't transport small molecules b) exist only by beta sheets c) show prostetic carbohydrate groups on the cytoplasmatic side d) have a hydrophobic transmembrane domain e) constitue about 10% of the membrane proteins Small molecules doesn't use transportproteins so it could be d, but again I'm not certain. 3. In watery solutions proteins conformation is decided by two factors: A maximum of the number of hydrogenbonding and: a) a minimize av entropy by the formation of a watery shell around the protein b) a rotation off polar amino acid residues out against the outer shell off the protein c) a rotation off hydrophobic amino acids sidechains towards the centre of the protein d) minimize off hydrophobic interactions e) maximize of ion interaction Here I actually don't have a clue, but someone told me it could be a?