Exam 14: Translation and Proteins

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

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

Studies of Neurospora led to the ________ statement,whereas studies of human hemoglobin led to the ________ statement.

The term peptidyl transferase relates to ________.

Exon shuffling is a term used to describe the movement of modular protein domains during protein evolution.As a result different genes specify similar domains.

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

Given the accompanying table: 1 2 3 4 Strain A + - + - Strain B + + + - Strain C + + + + Strain D - - + - Where numbers 1 through 4 indicate four supplements that must be added to sustain growth of the organism.Determine a possible metabolic pathway that would give the results seen for the four mutant strains,A through D.

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?

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. Strain MM MM + oxaloacetate MM + fumarate MM + malate MM + succinate 162 - + - + - 136 - + - - - 141 - + + + -

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?

List at least three posttranslational modifications known to occur as a newly synthesized protein matures.

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

The following table presents the effect of different media on the growth response of tryptophan mutations in Salmonella typhimurium (+ = growth,- = no growth). Strain No Supplement IGP AA IN TRY trp -8 - + + + + trp -2 - + - + + trp -3 - - - + + trp -1 - - - - + (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.

Prokaryotic and eukaryotic ribosomes are structurally and chemically identical.

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

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

The accompanying table is a set of experimental results relating the growth (+)of Neurospora on several media (MM = minimal medium).Based on the information provided,present the biochemical pathway and the locations of the metabolic blocks. Strain Medium MM + + s111 - + + t60 + + + s111 - - +

Which protein class directly controls many of the metabolic reactions within a cell?

During translation,which triplets signal chain termination?

What is the structure of fetal hemoglobin (HbF)?