TLS Online TPP Program

#Question id: 179


The average molecular weight of the 20 standard amino acids is 138, but biochemists use 110 when estimating the number of amino acids in a protein of known molecular weight.  Why?

#Unit 1. Molecules and their Interaction Relevant to Biology
  1. The number 110 is based on the fact that the average molecular weight of a protein is 110,000 with an average of 1,000 amino acids.

  2. The number 110 reflects the higher proportion of small amino acids in proteins, as well as the loss of water when the peptide bond forms.

  3. The number 110 reflects the number of amino acids found in the typical small protein, and only small proteins have their molecular weight estimated this way.

  4. The number 110 takes into account the relatively small size of nonstandard amino acids.

More Questions
TLS Online TPP Program

#Question id: 4111

#Unit 3. Fundamental Processes

Which of the following is NOT characteristic of a eukaryotic enhancer element?

TLS Online TPP Program

#Question id: 4112

#Unit 3. Fundamental Processes

Which of the following is the structure of the nucleotide at the branch site of a spliced intron?

TLS Online TPP Program

#Question id: 4113

#Unit 3. Fundamental Processes

Match the transcriptional machinery with their respective RNA Polymerase

TLS Online TPP Program

#Question id: 4114

#Unit 3. Fundamental Processes

Splice-site recognition is prone to two kinds of errors. First, splice sites can be skipped, with components bound at, for example, a given 5’ splice site pairing with those at a 3’ site beyond the correct one. Ways in which the accuracy of splice-site selection can be enhanced are as

A. The factors that recognize that site are transferred from the polymerase carboxy-terminal “tail” onto the RNA. Once in place, the 5’ splice site components are poised to interact with those other factors that bind to the next 3’ splice site to be synthesized.

B. SR (serine–arginine-rich) proteins bind to sequences called exonic splicing enhancers (ESEs) within the exons. SR proteins bound to these sites recruit the splicing machinery to the nearby splice sites to ensure correct splicing

C. By recruiting splicing factors to each side of a given exon, this process encourages the so-called “exon definition, contribute to correct splicing

D. Alternative splicing is intentional missplicing mechanism

Which of the following is INCORRECT?

TLS Online TPP Program

#Question id: 4115

#Unit 3. Fundamental Processes

The possible type of splicing outcome of given gene construct will be

TLS Online TPP Program

#Question id: 4116

#Unit 3. Fundamental Processes

Proteins that regulate splicing bind to specific sites called exonic (or intronic) splicing enhancers (ESE or ISE) or silencers (ESS and ISS). The former enhances, and the latter repress, splicing at nearby splice sites. Examples of splicing activator and repressors are as