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TLS Online TPP Program

#Question id: 3978

The 5'-terminal cap structure of eukaryotic mRNAs is a(n):

#Unit 3. Fundamental Processes

  1. 7-methylcytosine joined to the mRNA via a 2',3'-cyclic linkage.

  2.  7-methylguanosine joined to the mRNA via a 5' -> 3' diphosphate linkage.

  3. 7-methylguanosine joined to the mRNA via a 5' -> 5' triphosphate linkage.

  4. N6-methyladenosine joined to the mRNA via a 5' -> 5' phosphodiester bond.

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TLS Online TPP Program

#Question id: 15526

#Unit 4. Cell Communication and Cell Signaling

If a thymocyte randomly generated a TCR with an affinity for MHC Class I, the TCR and CD8 would bind MHC Class I together, and generate a signal that specifically initiated a program that is 
a) silenced CD8 expression
b) silenced CD4 expression
c) induced expression of genes specific for helper T-cell lineage function
d) induced expression of genes specific for cytotoxic T-cell lineage function
TLS Online TPP Program

#Question id: 884

#Unit 1. Molecules and their Interaction Relevant to Biology

The hydrogen bonds, which are central features of protein structures, then what is the reason behind it makes only minor contributions to protein stability?
TLS Online TPP Program

#Question id: 1878

#Unit 4. Cell Communication and Cell Signaling

Which of the following is the most prevalent primary immunodeficiency disease?
TLS Online TPP Program

#Question id: 15657

#Unit 13. Methods in Biology

You are studying a new strain of E. coli that can utilize the disaccharide melibiose very efficiently. You find that utilization depends on the enzyme melibiase, which is encoded by the gene Mel1. Mel1 is not expressed unless melibiose is present in the growth medium.
You next construct a MelA– MelB– double mutant, which gives the following behavior:
 
Which of your two models is consistent with this new data?
a) the MelA- MelB- double mutant is identical to the MelB- mutant
b) MelA- is epistatic to MelB-
c) MelB- is epistatic to MelA-
d) the MelA- MelB- double mutant is identical to the MelA- mutant
Which of the following is the correct prediction about the double mutants?
TLS Online TPP Program

#Question id: 4143

#Unit 3. Fundamental Processes

It is possible to convert the Cys that is a part of Cys-tRNACys to Ala by a catalytic reduction.  If the resulting Ala-tRNACys were added to a mixture of (1) ribosomes, (2) all the other tRNAs and amino acids, (3) all of the cofactors and enzymes needed to make protein in vitro, and (4) mRNA for hemoglobin, where in the newly synthesized hemoglobin would the Ala from Ala-tRNACys be incorporated?