Exam 15: Translation of MRNA

You perform a cell free translation experiment like Nirenberg and Matthaei,but you forget to write down what nucleotides you added to make the mRNA.You precipitate the translated polypeptides and measure the relative amount of radiolabeled amino acids incorporated into them. You get 25% proline,25% threonine,12.5% glutamine,12.5% lysine,12.5% asparagine,and 12.5% histidine. What nucleotides and in what % did you add to make the mRNA?

The scientist(s)________ created a cell-free translation system.An mRNA template was added to a number of tubes,each containing amino acids with a different one radiolabeled.Radiation was measured from the precipitated protein,and this corresponded to the mRNA template that had been added.This was the first experiment that demonstrated the ability to synthesize polypeptides from synthetic mRNA,and revealed a relationship between the two.

The first person to suggest that a connection exists between the function of a gene and the production of an enzyme was Archibald Garrod.

The scientist(s)________ developed a novel method to synthesize RNA.Short RNAs of 2 to 4 nucleotides were linked together to create a copolymer.The resulting peptide created after translation revealed the 3-letter code for the amino acids.

All mature polypeptides contain a methionine at the N-terminus.

Which component of the ribosome is able to detect when the wrong tRNA has inserted into the A site?

Which of the following would be considered an activated amino acid?

Francis Crick proposed the adaptor hypothesis,and later the adaptor was discovered to be ________.

Which of the following codons is NOT degenerate to CUU?

Mutations in the enzyme homogentisic acid oxidase are associated with alkaptonuria.Select all characteristics of homogentisic acid oxidase.

Suppose you performed a triplet binding assay with the triplet 5′-UAA-3′.What radiolabeled amino acids do you expect to find bound to the filter?

The scientist(s)________ developed the triplet-binding assay.Samples containing ribosomes and a particular RNA triplet were exposed to charged tRNAs with different radiolabeled amino acids.Only the amino acid whose tRNA matched the triplet would bind the ribosome.The triplet-binding assay established relationships between particular triplet sequences and specific amino acids.

The enzyme that attaches free amino acids to the tRNA molecule is called tRNA attachase.

What level of protein structure is exemplified by α-helices and β-sheets?

The primary structure of a protein refers to

What is responsible for binding the initiator tRNA in prokaryotes and eukaryotes?

The genetic code - the correspondence between codons and amino acids - is unique for each species of organism.

 You are studying the DNA of a person who you know has two defective copies of the gene that encodes phenylalanine hydroxylase. You are surprised to find that this person also carries two defective copies of the gene for homogentisic acid oxidase. What disease symptoms will this person exhibit? (Assume pathway intermediates are not available from sources outside the phenylalanine breakdown pathway.)

In bacteria,the sequence that facilitates the binding of the mRNA to the ribosome is called the