Proteins

Question 1

What are the 4 levels of protein structure?

Answer 1

Primary, Secondary, Tertiary, Quaternary

Question 2

What is the 1st level of protein structure?

Answer 2

Primary: refers to the amino acid sequence.

Amino acids are linked linearly by peptide bonds

Question 3

What is the 2nd level of protein structure?

Answer 3

Secondary: refers to the conformation adopted by local regions of the protein chain.
Chains fold into alpha helixes or beta sheets through hydrogen bonding

Question 4

What is the 3rd level of protein structure?

Answer 4

Tertiary structure.

Additional folding caused by hydrophobic (interior) and hydrophilic (exterior) interactions

Question 5

What’s is the 4th level of protein structure?

Answer 5

Quaternary structure. Consists of more than one chain. Subunits are joined together by noncovalent bonds

Question 6

What determines the structure of a protein?

Answer 6

The amino acid sequence determines the 3D structure and all of its other properties

Question 7

What are the interactions that help create protein tertiary structure?

Answer 7

1) hydrogen bonding, 2) disulfide bonds, 3) hydrophobic/hydrophilic interactions, 4) ionic interactions, 5) Van der Walls forces, and 6) proline turns

Question 8

What are the protein dewatering agents?

Answer 8

• Acid
• Heat
• Urea
• Mercaptoethanol

Question 9

What do you need to do to re-nature a protein?

Answer 9

Remove the dewatering agent