Question 1

Consider the following forms of the amino acid alanine (Ala).Which statement concerning these structures is FALSE?

Accepted Answer

A

Question 2

What disease results from a deficiency of vitamin C?

Accepted Answer

Scurvy results from a deficiency of vitamin C, leading to symptoms like bleeding gums, weakness, and bruising due to the body's inability to produce collagen.

Question 3

What two functional groups characterize the amino acids found in human proteins?

Accepted Answer

Amino acids, the building blocks of proteins, are characterized by having both a carboxylate group (-COOH) and an amino group (-NH2).

Question 4

Which of the following statements concerning sickle cell anemia is FALSE?

Accepted Answer

The presence of sickle cell trait is associated with increased resistance to malaria, not diabetes. This trait provides a selective advantage in regions where malaria is prevalent, which explains its higher frequency in those populations.

Question 5

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

Accepted Answer

The amino group of arginine is the terminal end of the peptide and is not joined to any other amino acid, making this statement incorrect.

Question 6

The amino acid 5-hydroxylysine is found in collagen.Which of the following represents the structure of this unusual amino acid?

Accepted Answer

The answer of The amino acid 5-hydroxylysine is found in...

Question 7

Hemoglobin and glycoproteins are two examples of proteins that contain a prosthetic group.What is a prosthetic group?

Accepted Answer

A prosthetic group is a nonprotein component that is covalently bonded to a protein, allowing the protein to perform its function. For example, the heme group in hemoglobin is a prosthetic group that is essential for oxygen transport.

Question 8

What protein is the oxygen storage protein of the skeletal muscles?

Accepted Answer

Myoglobin is the oxygen storage protein found in skeletal muscles. It binds oxygen more tightly than hemoglobin, allowing it to serve as an oxygen reserve for muscle cells during intense physical activity.

Question 9

Which of the statements concerning protein structure is NOT true?

Accepted Answer

Secondary structure refers to the local folded structures that form within a polypeptide due to interactions between atoms of the backbone. The most common types of secondary structures are the alpha helix and beta sheet, which are stabilized by hydrogen bonds between the backbone atoms, not peptide bonds. Peptide bonds are involved in linking amino acids together in the primary structure.

Question 10

What are the two most common types of secondary structure found in proteins?

Accepted Answer

The two most common types of secondary structure found in proteins are α-helices and β-pleated sheets. These structures are stabilized by hydrogen bonds between the backbone atoms of the polypeptide chain.

Question 11

What is the term for the state of a protein when its organized structure has become completely disorganized?

Accepted Answer

Denaturation refers to the process where a protein loses its native, organized structure due to external stress or conditions such as pH, temperature, or chemical exposure, leading to a loss of biological function.

Question 12

What term is used to describe the amino acid that has the free carboxylate group in a peptide?

Accepted Answer

The C-terminal amino acid in a peptide or protein is the one that has a free carboxyl group (-COOH) not involved in a peptide bond, thus it is at the end of the amino acid chain.

Question 13

Amino acids are the building blocks of proteins.Which of the following statements concerning amino acids is FALSE?

Accepted Answer

The answer of Amino acids are the building blocks of...

Question 14

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?

Accepted Answer

The answer of Proteins are long chains of amino acids...

Question 15

What is meant by the "tertiary structure" of a protein?

Accepted Answer

The tertiary structure of a protein refers to its overall three-dimensional shape, which is crucial for the protein's function. This structure is determined by interactions among various amino acid side chains and the protein's environment.

Question 16

Which of the following is a structural protein?

Accepted Answer

Keratin is a structural protein, crucial for the structure of hair, nails, and the outer layer of skin.

Question 17

Tuftsin is a tetrapeptide that stimulates and promotes the destruction of tumor cells.What is meant by the term tetrapeptide?

Accepted Answer

A tetrapeptide is composed of four amino acids linked together by peptide bonds.

Question 18

Which structural protein is found in bone,tendon,and skin?

Accepted Answer

Collagen is the primary structural protein found in bone, tendon, and skin, providing strength and structure to these tissues.

Question 19

The properties of amino acids and the proteins they compose are based on the nature of their side chain group.Which term best classifies the side chain of the amino acid phenylalanine?

Accepted Answer

The answer of The properties of amino acids and the...

Question 20

What is meant by the "quaternary structure" of a protein?

Accepted Answer

The quaternary structure of a protein refers to the way in which two or more polypeptide chains come together and arrange themselves to form a fully functional protein complex. This structure is critical for the protein's biological function.

Quiz 18: Protein Structure and Function

Consider the following forms of the amino acid alanine (Ala) .Which statement concerning these structures is FALSE?