Exam 13: Translation and Proteins

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 β chain of adult hemoglobin is composed of 146 amino acids of a known sequence.In comparing the normal β chain with the β chain in sickle cell hemoglobin,what alteration is one likely to find?

Side groups of amino acids are typically classified under which of the following?

Prokaryotic and eukaryotic ribosomes are structurally and chemically identical.

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?

What is the structure of HbF,fetal hemoglobin?

Sickle-cell anemia is caused by the absence of the alpha chain of hemoglobin.

The primary structure of a protein is determined by ________.

The ribonucleic acid components known to exist in eukaryotic ribosomes are the following: 5.8S,18S,28S,and 5S.

The following drawing represents simultaneous transcription and translation in E.coli. Answer the questions below the drawing.The arrow gives the direction of the RNA polymerase. (a)Is the letter A nearer the 5' or the 3' end of the molecule? (b)Is the letter B nearer the 5' or the 3' end of the molecule? (c)Is the letter C nearer the 5' or the 3' end of the tRNA molecule? (d)What is the "S" value for the large rRNA that is closest to the letter D? (e)Which terminus (N or C)of the growing polypeptide chain is nearer to the letter E?

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.)

The secondary structure of a protein is dependent on polar interactions among the side chains of the amino acids.

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

The secondary structure of a protein includes ________.

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

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

What is the general ethnic distribution of the sickle-cell gene?

Assuming that an amino acid sequence is 250 amino acids long,how many different molecules,each with a unique sequence,could be formed?

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

The problem below relates to the synthesis of several intermediates in the citric acid cycle,which is essential in the production of ATP through aerobic respiration.A set of experimental results relating the growth (+)of Neurospora on several media is given in the table.Based on the information provided,present the biochemical pathway for the substances oxaloacetate,fumarate,malate,and succinate and the locations of the metabolic blocks produced by the various strains.