BIOC 3021 Exam 1 2026 Questions With Complete
Solutions
Does Cysteine form disulfide bonds?
Yes
Which amino acid form is uncommon in proteins?
D-isomer
Which group loses protons first as pH increases?
Carboxyl group
Which amino acid has an R-group pKa near 6?
Histidine
Which amino acid contains a guanidino group?
Arginine
Do all 3 peptide backbone bonds rotate freely?
No
What technique is used to determine the amino acid sequence of
a protein?
Edman degradation
What type of bond links the two chains of insulin?
Disulfide bonds
Are β-sheets are stabilized mainly by hydrophobic interactions?
No
, What is the main role of disulfide bonds in proteins?
They form covalent links within or between protein chains
What interaction is most important for stabilizing secondary
structure?
Hydrogen bonds
What do Ramachandran plots show?
Which phi and psi angles are sterically allowed in proteins
Do α-helices have a large, hollow center?
No
How are R-groups arranged around an α-helix?
Separated by about 90° of rotation
Does polar side chains clustering away from water strongly
influence tertiary structure?
No
What is true about protein domains?
They are often globular and semi-independent units
What is true about quaternary structure?
Subunits interact via noncovalent bonds and sometimes
disulfides
Why does myoglobin lack quaternary structure?
It consists of only one polypeptide chain
What is the largest organizational unit within tertiary structure?
Solutions
Does Cysteine form disulfide bonds?
Yes
Which amino acid form is uncommon in proteins?
D-isomer
Which group loses protons first as pH increases?
Carboxyl group
Which amino acid has an R-group pKa near 6?
Histidine
Which amino acid contains a guanidino group?
Arginine
Do all 3 peptide backbone bonds rotate freely?
No
What technique is used to determine the amino acid sequence of
a protein?
Edman degradation
What type of bond links the two chains of insulin?
Disulfide bonds
Are β-sheets are stabilized mainly by hydrophobic interactions?
No
, What is the main role of disulfide bonds in proteins?
They form covalent links within or between protein chains
What interaction is most important for stabilizing secondary
structure?
Hydrogen bonds
What do Ramachandran plots show?
Which phi and psi angles are sterically allowed in proteins
Do α-helices have a large, hollow center?
No
How are R-groups arranged around an α-helix?
Separated by about 90° of rotation
Does polar side chains clustering away from water strongly
influence tertiary structure?
No
What is true about protein domains?
They are often globular and semi-independent units
What is true about quaternary structure?
Subunits interact via noncovalent bonds and sometimes
disulfides
Why does myoglobin lack quaternary structure?
It consists of only one polypeptide chain
What is the largest organizational unit within tertiary structure?
