UNE BIOCHEM 1005 WEEK 1 QUESTIONS
WITH COMPLETE SOLUTIONS
What are the four different protein structures? correct answer:
1. Primary
2. Secondary
3. Tertiary
4. Quaternary
What is the primary structure of a protein? correct answer: a
linear sequence of amino acids in polypeptide chains which is
written from the amino terminus (N-terminus) to the carboxyl
terminus (C-terminus)
What is the secondary structure made of? correct answer: a-
helix, b-sheets, and bends, turns, or loops
How are alpha helices formed? correct answer: They are formed
when the carbonyl group of peptide bonds form a hydrogen
bond with the amide hydrogen located 4 residues down the
chain.
Approximately how much of all secondary structures are a-
helices? correct answer: 1/3
What is not typically found in secondary structures and why?
correct answer: Proline, because it forms a non-traditional
peptide bond and adds a "kink" in the helix
, How are beta sheets formed? correct answer: They are formed
when beta strands are connected laterally by at least two or three
backbone hydrogen bonds
How are the b-strands connected and and by what? correct
answer: They are horizontally by hydrogen bonds formed
between C=O groups of either strand and NH groups of either
strand
B-sheets can either be _____________ or _________________.
correct answer: parallel or anti-parallel
Where does the R group always protrude to? correct answer:
The top or bottom
Depending on the R groups on the sides of the B-sheet, the sheet
may have a ________________ and a ________________ side.
correct answer: hydrophilic and hydrophobic
Where will the hydrophilic side of the sheet be? correct answer:
on the surface of the protein and be exposed to the polar H2O
solvent.
Where will the hydrophobic side of the sheet be? correct answer:
It will be buried in the protein and will only rarely be exposed to
the polar H2O solvent.
What are bends, turns, or loops? correct answer: Short stretched
areas of the polypeptide chain from these structures that are
stabilized by hydrogen bonds (these are not random)
WITH COMPLETE SOLUTIONS
What are the four different protein structures? correct answer:
1. Primary
2. Secondary
3. Tertiary
4. Quaternary
What is the primary structure of a protein? correct answer: a
linear sequence of amino acids in polypeptide chains which is
written from the amino terminus (N-terminus) to the carboxyl
terminus (C-terminus)
What is the secondary structure made of? correct answer: a-
helix, b-sheets, and bends, turns, or loops
How are alpha helices formed? correct answer: They are formed
when the carbonyl group of peptide bonds form a hydrogen
bond with the amide hydrogen located 4 residues down the
chain.
Approximately how much of all secondary structures are a-
helices? correct answer: 1/3
What is not typically found in secondary structures and why?
correct answer: Proline, because it forms a non-traditional
peptide bond and adds a "kink" in the helix
, How are beta sheets formed? correct answer: They are formed
when beta strands are connected laterally by at least two or three
backbone hydrogen bonds
How are the b-strands connected and and by what? correct
answer: They are horizontally by hydrogen bonds formed
between C=O groups of either strand and NH groups of either
strand
B-sheets can either be _____________ or _________________.
correct answer: parallel or anti-parallel
Where does the R group always protrude to? correct answer:
The top or bottom
Depending on the R groups on the sides of the B-sheet, the sheet
may have a ________________ and a ________________ side.
correct answer: hydrophilic and hydrophobic
Where will the hydrophilic side of the sheet be? correct answer:
on the surface of the protein and be exposed to the polar H2O
solvent.
Where will the hydrophobic side of the sheet be? correct answer:
It will be buried in the protein and will only rarely be exposed to
the polar H2O solvent.
What are bends, turns, or loops? correct answer: Short stretched
areas of the polypeptide chain from these structures that are
stabilized by hydrogen bonds (these are not random)
