Amino Acids Peptides And Proteins - Lehninger Principles of Biochemistry | Biology+

Course

Biotechnology

Study Pack

Set 1: The Foundations of Biochemistry

Set 3: Amino Acids, Peptides, and Proteins

Set 4: The Three-Dimensional Structure of Proteins

Set 5: Protein Function

Set 7: Carbohydrates and Glycobiology

Set 8: Nucleotides and Nucleic Acids

Set 9: DNA-Based Information Technologies

Set 11: Biological Membranes and Transport

Set 12: Biosignaling

Set 13: Bioenergetics and Biochemical Reaction Types

Set 14: Glycolysis, Gluconeogenesis, and the Pentose Phosphate Pathway

Set 15: Principles of Metabolic Regulation

Set 16: The Citric Acid Cycle

Set 17: Fatty Acid Catabolism

Set 18: Amino Acid Oxidation and the Production of Urea

Set 19: Oxidative Phosphorylation and Photophosphorylation

Set 20: Carbohydrate Biosynthesis in Plants and Bacteria

Set 21: Lipid Biosynthesis

Set 23: Hormonal Regulation and Integration of Mammalian Metabolism

Set 24: Genes and Chromosomes

Set 25: DNA Metabolism

Set 26: RNA Metabolism

Set 27: Protein Metabolism

Set 28: Regulation of Gene Expression

Set 3 Amino Acids Peptides And Proteins

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Set 3 Amino Acids Peptides And Proteins

(Multiple Choice)

Free

Titration of valine by a strong base, for example NaOH, reveals two pK's. The titration reaction occurring at pK₂ (pK₂ = 9.62) is:

A) -COOH + OH^-

\rightarrow

-COO^- + H₂O.
B) -COOH + -NH₂

\rightarrow

-COO^- + -NH₂⁺.
C) -COO^- + -NH₂⁺

\rightarrow

-COOH + -NH₂.
D) -NH₃⁺ + OH^-

\rightarrow

-NH₂ + H₂O.
E) -NH₂ + OH^-

\rightarrow

-NH^- + H₂O.

Answer

(Multiple Choice)

Free

The uncommon amino acid selenocysteine has an R group with the structure -CH₂-SeH (pK_a

\approx

5). In an aqueous solution, pH = 7.0, selenocysteine would:

A) be a fully ionized zwitterion with no net charge.
B) be found in proteins as D-selenocysteine.
C) never be found in a protein.
D) be nonionic.
E) not be optically active.

Answer

(Multiple Choice)

Free

Two amino acids of the standard 20 contain sulfur atoms. They are:

A) cysteine and serine.
B) cysteine and threonine.
C) methionine and cysteine
D) methionine and serine
E) threonine and serine.

Answer