Question 1

Amino acids are named that because each one

Accepted Answer

A) is a unique carboxylic acid. 
B) has a standard configuration. 
C) is a carboxyl derivative of an amide acid. 
D) is an amino derivative of a carboxylic acid. 
A) is a unique carboxylic acid. 
B) has a standard configuration. 
C) is a carboxyl derivative of an amide acid. 
D) is an amino derivative of a carboxylic acid.

Question 2

Disulfide bridges can form in proteins ________.

Accepted Answer

A) only between cysteine residues side-by-side in the protein sequence 
B) between cysteine residues that are close in three-dimensional space,but not necessarily close in the primary structure 
C) between two cystine residues in proteins 
D) between any two methionines or cysteines 
A) only between cysteine residues side-by-side in the protein sequence 
B) between cysteine residues that are close in three-dimensional space,but not necessarily close in the primary structure 
C) between two cystine residues in proteins 
D) between any two methionines or cysteines

Question 3

An octapeptide was determined to have the following amino acid composition: Lys (2),Phe (2),Gly (1),His (1),Leu (1),Met (1).The native peptide was run through one cycle of the Edman degradation and the PTH-leucine derivative was identified by HPLC.When the native peptide was exposed to cyanogen bromide (BrCN),a heptapeptide and free glycine were recovered.Incubation of the native protein with trypsin gave a tetrapeptide,a tripeptide,and free lysine.The peptides were separated and each run through one cycle of the Edman degradation.The tetrapeptide yielded the PTH-leucine derivative,and the tripeptide yielded the PTH-phenylalanine derivative.Incubation of the native protein with pepsin produced a dipeptide and two tripeptides.The amino acid composition of the tripeptides (not the order)were determined to be (Phe,Gly,Met)and (Phe,Lys,Lys).What is the sequence of the octapeptide?
Specificities of Proteases
BrCN cuts at the C-terminal side of Met
Trypsin cuts at the C-terminal side of Lys or Arg
Pepsin cuts at the N-terminal side of Phe,Trp or Tyr

Accepted Answer

A) Leu-His-Phe-Lys-Lys-Phe-Met-Gly 
B) Gly-Met-Phe-Lys-Lys-Phe-His-Leu 
C) Met-Leu-Phe-Lys-Phe-Gly-Lys-His 
D) Leu-His-Lys-Lys-Phe-Phe-Gly-Met 
E) His-Phe-Leu-Lys-Lys-Phe-Met-Gly 
A) Leu-His-Phe-Lys-Lys-Phe-Met-Gly 
B) Gly-Met-Phe-Lys-Lys-Phe-His-Leu 
C) Met-Leu-Phe-Lys-Phe-Gly-Lys-His 
D) Leu-His-Lys-Lys-Phe-Phe-Gly-Met 
E) His-Phe-Leu-Lys-Lys-Phe-Met-Gly

Question 4

The amino acids in polypeptide chains which contain sulfur (S)are

Accepted Answer

A) cysteine,cystine,and methionine. 
B) cystine. 
C) methionine only. 
D) cysteine only. 
E) cysteine and methionine. 
A) cysteine,cystine,and methionine. 
B) cystine. 
C) methionine only. 
D) cysteine only. 
E) cysteine and methionine.

Question 5

The number of commonly found amino acids with only one chiral carbon is

Accepted Answer

A) 17. 
B) 18. 
C) 19. 
D) 20. 
A) 17. 
B) 18. 
C) 19. 
D) 20.

Question 6

Alanine,valine,leucine and isoleucine are important in three dimensional structure because they

Accepted Answer

A) are branched. 
B) are highly hydrophobic. 
C) are highly hydrophilic. 
D) attract water molecules. 
A) are branched. 
B) are highly hydrophobic. 
C) are highly hydrophilic. 
D) attract water molecules.

Question 7

Which is used as the basis of separation of proteins by affinity chromatography?

Accepted Answer

A) The net charge and pI of the protein at the pH of the column. 
B) The protein's molecular weight. 
C) The protein's density. 
D) The selective binding of the protein to a ligand on the column matrix. 
A) The net charge and pI of the protein at the pH of the column. 
B) The protein's molecular weight. 
C) The protein's density. 
D) The selective binding of the protein to a ligand on the column matrix.

Amino acids are named that because each one

Disulfide bridges can form in proteins ________.

The amino acids in polypeptide chains which contain sulfur (S)are

The number of commonly found amino acids with only one chiral carbon is

Alanine,valine,leucine and isoleucine are important in three dimensional structure because they

Which is used as the basis of separation of proteins by affinity chromatography?

Introduction to Biochemistry

Water

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters

Exam 3: Amino Acids and the Primary Structures of Proteins

Amino acids are named that because each one

Disulfide bridges can form in proteins ________.

The amino acids in polypeptide chains which contain sulfur (S)are

The number of commonly found amino acids with only one chiral carbon is

Alanine,valine,leucine and isoleucine are important in three dimensional structure because they

Which is used as the basis of separation of proteins by affinity chromatography?

Introduction to Biochemistry

Water

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters