Biology: Amino Acids and Proteins

Which of the following best describes phenylalanine?

Which of the following amino acids is most likely a precursor of the neurotransmitter GABA?

A researcher is studying the secondary structure of an enzyme involved in intermediary metabolism. He observes that it contains alpha-helices. Which of the following best describes this structure?

A research group is studying covalent bonds which are formed by the side chains of amino acids. Which of the following bonds is most likely being studied by this research group?

Which of the following best describes gene expression in bacteria?

Which of the following positions best indicates the first nucleotide of the anticodon?

A research laboratory studies a disease-causing gene that leads to loss of function of an enzyme in a metabolic pathway. Karyotyping and DNA microarray shows that the chromosome structure is unchanged. Northern blot analysis shows no change in the mRNA transcript of the gene. Western blot shows a smaller than normal protein is formed.

Which of the following modifications is most likely observed during the process of primary insulin translation product undergoing modifications to produce the mature insulin hormone?

A researcher has developed a bacterial strain in the laboratory with reduced rates of translation. It has a mutation which confers decreased activity in peptide bond formation during ribosomal protein synthesis. A Mutation in which of the following is most consistent with these findings?

Which of the following codon changes best explains the loss of an important alpha-helical segment of the protein?

Which of the properties of the code in the novel organism is most likely different from the terrestrial (earth) genetic code?

Which of the following processes is most likely inhibited by the antibiotic erythromycin?