Question :
1.Amino acids the building blocks of proteins. Which of the : 1318493
1.Amino acids are the building blocks of proteins. Which of the following statements concerning amino acids is FALSE?
A) There are 20 different amino acids that occur naturally in human proteins.
B) The amino acids that make up human proteins are called essential amino acids.
C) The amino acids present in human proteins are “alpha” amino acids.
D) Except for glycine, where R=H, amino acids are chiral molecules.
E) Amino acids are classified by the nature of the side chain R groups that are present.
2.What two functional groups characterize the amino acids found in human proteins?
A) primary amine group and a carboxyl group
B) amino group and an amide group
C) primary amine group and aldehyde group
D) primary amine group and ketone group
E) amino group and aldehyde group
3.What term is used to describe the amino acid that has the free carboxylate group in a peptide?
A) acid end
B) C’ group
C) C-terminal amino acid
D) primary amino acid
E) tertiary amino acid
4.Which of the statements concerning protein structure is NOT true?
A) The primary structure of a protein describes the unique sequence of amino acids in the protein chain.
B) Secondary structure describes the peptide bonds joining the amino acids together in the protein chain.
C) Tertiary structure describes the overall three dimensional shape of a protein.
D) Quaternary structure describes the association of two or more polypeptide chains to form one functioning protein unit.
E) Hydrogen bonding, disulfide bonds, salt bridges, and van der Waals forces are responsible for maintaining the tertiary structure of a protein.
5.What are the two most common types of secondary structure found in proteins?
A) ?-helices and ?-arrays
B) double stranded helices and ?-arrays
C) ?-helices and ?-pleated sheets
D) ?-spirals and ?-turns
E) random coils and ?-pleated sheets
6.Which structural protein is found in bone, tendon, and skin?
A) collagen
B) fibrinogen
C) albumin
D) keratin
E) insulin
7.What disease results from a deficiency of vitamin C?
A) diabetes
B) sickle cell
C) scurvy
D) Alzheimer’s
E) lactose intolerance
8.The amino acid 5-hydroxylysine is found in collagen. Which of the following represents the structure of this unusual amino acid?
A) I
B) II
C) III
D) IV
E) None of the structures represent 5-hydroxylysine.
9.Proteins are long chains of amino acids joined together by peptide bonds. Which of the following properly depicts the peptide bond formed between two generic amino acids?
A)
B)
C)
D)
E)
10.Tuftsin is a peptide that stimulates and promotes the destruction of tumor cells. Its primary structure is shown below. Which of the following is NOT a valid interpretation of its primary structure?
Thr-Lys-Pro-Arg
A) It is a tetrapeptide.
B) It contains three peptide bonds.
C) Threonine is the N-terminal amino acid and arginine is the C-terminal amino acid.
D) The carboxyl group of lysine is joined to the amino group of proline.
E) The amino group of arginine is not joined to any other amino acid.
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