Exam 13: Translation and Proteins

Nutritional mutants in Neurospora can be "cured" by treating the medium with substances in the defective metabolic pathway. What determines whether the mutant strain (auxotroph) is "cured" by a particular substance?

When a metabolic block occurs in a biochemical pathway, it is common for the amount of the substance immediately prior to that block to increase.

The primary structure of a protein is determined by _.

Regarding the protein structure, how are fi -pleated sheets arranged and stabilized?

The one -gene:one -enzyme hypothesis emerged from work on which two organisms?

A procedure that is often used to separate molecules by using their molecular charges is called _.

Early in the 1900s, Sir Archibald Garrod studied a number of metabolic defects in humans. One particular disorder involved the inability to metabolize homogentisic acid. What is the name of this disorder?

What is the expected proportion of offspring with sickle -cell anemia if both partners are heterozygous for the sickle -cell anemia gene?

Which of the following are among the major components of prokaryotic ribosomes?

rDNA is the portion of a genome that is involved in the production of ribosomal RNA.

A short segment of an mRNA molecule is shown below. The polypeptide it codes for is also shown: 5' -AUGGUGCUGAAG : methionine -valine -leucine -lysine Assume that a mutation in the DNA occurs so that the fourth base (counting from the 5' end) of the messenger RNA now reads A rather than G. What sequence of amino acids will the mRNA now code for? (You do not need a copy of the genetic code to answer the question.)

In what ways do the amino acid side chains interact to influence protein function?

Electrophoretic separation of HbA from HbS is based on a difference in their _.

The primary structure of a protein is composed of the sequence of amino acids in that protein.

The following table presents the effect of different media on the growth response of tryptophan mutations in Salmonella typhimurium (+ = growth, - = no growth). a() Construct the biochemical pathway for the compounds IGP, AA, IN, and TRY based on these data. b() Place strains of bacteria (mutations) in the appropriate steps in the pathway. c() In bacteria, it is often possible to make partial diploid strains. Assume that a diploid strain was made containing the complete genomes of the trp -2 and trp -1 strains. Would this diploid strain be able to grow on the unsupplemented medium? Explain your answer.

Draw and label the spatial and polarity relationships among the following translational components: ribosome (small and large subunits), growing polypeptide chains, amino acid attachment to tRNA, mRNA, codon, and anticodon.

Proteins are composed of strings of nucleotides connected by 5' -3' phosphodiester bonds.

Below are several phenomena relating to protein structure. Clearly describe each phenomenon, the conditions under which each occurs, and the probable influence each has on protein structure. a() hydrophobic interactions b() hydrogen bonds c() disulfide bridges

Considering the types of side chains on amino acids and their relationship to protein structure, where are the amino acids with hydrophobic side chains most likely to be located?

Assume that a base addition occurs early in the coding region of a gene. Is the protein product of this gene expected to have more or fewer altered amino acids compared with the original gene with a base deletion late in the coding region?