2.7.3 Primary and Secondary Structure

Question 1

primary structure

Answer 1

• a protein is the specific sequence of the amino acids in a polypeptide. A single change in primary structure can significantly change the shape of a polypeptide.
• The order and arrangement of amino acids within a polypeptide chain determines the shape of a protein.

Question 2

secondary structure

Answer 2

• a protein is the regular pattern of local hydrogen bonding within the polypeptide chain. Examples of secondary structure within a polypeptide include the alpha helix and beta pleated sheet.

Question 3

note

Answer 3

• Proteins are macromolecules that do much of the work of the cell.
• The shape of a protein determines its function. The order and arrangement of amino acids within a polypeptide chain determine the shape of a protein. RNA, in turn, instructs the amino acids to bond in a particular sequence.

Question 4

alpha helix

Answer 4

• one type of secondary structure. The polypeptide twists into a helix that is supported by hydrogen bonds between the amine group hydrogen and the carboxyl
  oxygen.

Question 5

beta pleated sheet

Answer 5

• another type of secondary structure. It is formed when the polypeptide chain folds, placing two chains next to each other. Hydrogen bonding occurs between the chains, forming a sheet-like region within the polypeptide

Question 6

Which statement regarding the secondary structure of a protein is correct?

a. It is maintained by disulfide bonds between cysteine molecules.
b. It may be in either the alpha-helix or the beta-pleated sheet configuration.
c. It is destroyed if the protein is placed in an atmosphere of 21% oxygen and 78% nitrogen.
d. It refers to the manner in which two polypeptides coil and wrap around each other.

Answer 6

• b. It may be in either the alpha-helix or the beta-pleated sheet configuration

Question 7

Two major types of secondary structure found in proteins are

Answer 7

• α-helices and β-pleated sheets

Question 8

The linear sequence of amino acids joined by peptide bonds is the __________ structure of a protein

Answer 8

• primary

Question 9

Which statement about the primary structure of a protein is not true?

a. The primary structure of a protein determines the corresponding secondary structure.
b. The primary structure of a protein is determined by the nucleotide sequence of the corresponding gene. c. The primary structure of a protein is determined by hydrogen bonding.
d. The primary structure of a protein is the sequence of amino acids in that protein.

Answer 9

• c. The primary structure of a protein is determined by hydrogen bonding

Question 10

Primary structure describes

Answer 10

• the order of amino acids in a protein

Question 11

The primary structure of a protein is determined by

Answer 11

• RNA sequence

Question 12

The secondary structure of a protein

Answer 12

• is influenced by hydrogen bonding

- can assume an alpha-helix or beta-pleated sheet formation