DREXEL BIO 209 FINAL EXAM COMPLETE
STUDY GUIDE AND MOLECULAR BIOLOGY
REVIEW 2026
◉ chemical bonds.
Answer: strong- covalent ( enzymes can change them)
weak/non covalent- protein folding, membranes, transport,
substrate binding
◉ neg side chain amino acids.
Answer: apartic acid(Asp-D)
glutamic acid (Glu-E)
◉ positive side chain amino acids.
Answer: Arginine(Arg-R)
Lysine (Lys-K)
Histidine (His-H)
◉ uncharged polar side chain.
Answer: Asparagine (Asn-N)
Glutamine (Gln-Q)
,Serine (Ser-S)
Threosine (Thr-T)
Tyrosine (Tyr-Y)
◉ nonpolar amino acids.
Answer: alanine (ala- A)
glycine (gly-G)
valine (val-V)
leucine (leu-L)
isoleucine (ile-I)
proline (pro-P)
phenylalanine (phe-F)
methionine (met- M)
tryptophan (trp-W)
cytesine (cys-C)
◉ all amino acids have.
Answer: H atom
carboxyl group
amino group
Rgroup (differentiating factor)
,◉ Linus Pauling and Robert Corey.
Answer: X ray crystallography
- found alpha helix and beta pleated sheets (both interchain H
bonding)
◉ bonds between each amino acid.
Answer: peptide bond
amino acid chain= polypeptide backbone
polar and nonpolar amino acids face opp sides in backbone
◉ electrostatic interactions.
Answer: between carboxyl and amino group of different amino acids
◉ van der waals interactions.
Answer: between methyl group off of side chains
◉ alpha helix.
Answer: tightly coiled
rod arrangement of amino acids
R-grop radiates outwards
backbone is repeating units of amino group bonded to carbonyl
group
, (n+4 rule)
3.6 amino acids per turn
right handed
◉ a helix cont..
Answer: two or more a helices intertwine to form coiled coil (ex.
keratin, fibrin, myosin)
hemoglobin high in a helix content
chymotrypsin lacks a helix
◉ b pleated sheet.
Answer: forms sheet by H bonding between amino and carboxyl
groups of dif peptide chains
parallel, antiparallel, mixed
extended polypeptide chains
◉ levels of protein structure.
Answer: primary- amino acid residues
secondary- alpha helix
tertiary- polypeptide chain
quaternary- assembled subunits
STUDY GUIDE AND MOLECULAR BIOLOGY
REVIEW 2026
◉ chemical bonds.
Answer: strong- covalent ( enzymes can change them)
weak/non covalent- protein folding, membranes, transport,
substrate binding
◉ neg side chain amino acids.
Answer: apartic acid(Asp-D)
glutamic acid (Glu-E)
◉ positive side chain amino acids.
Answer: Arginine(Arg-R)
Lysine (Lys-K)
Histidine (His-H)
◉ uncharged polar side chain.
Answer: Asparagine (Asn-N)
Glutamine (Gln-Q)
,Serine (Ser-S)
Threosine (Thr-T)
Tyrosine (Tyr-Y)
◉ nonpolar amino acids.
Answer: alanine (ala- A)
glycine (gly-G)
valine (val-V)
leucine (leu-L)
isoleucine (ile-I)
proline (pro-P)
phenylalanine (phe-F)
methionine (met- M)
tryptophan (trp-W)
cytesine (cys-C)
◉ all amino acids have.
Answer: H atom
carboxyl group
amino group
Rgroup (differentiating factor)
,◉ Linus Pauling and Robert Corey.
Answer: X ray crystallography
- found alpha helix and beta pleated sheets (both interchain H
bonding)
◉ bonds between each amino acid.
Answer: peptide bond
amino acid chain= polypeptide backbone
polar and nonpolar amino acids face opp sides in backbone
◉ electrostatic interactions.
Answer: between carboxyl and amino group of different amino acids
◉ van der waals interactions.
Answer: between methyl group off of side chains
◉ alpha helix.
Answer: tightly coiled
rod arrangement of amino acids
R-grop radiates outwards
backbone is repeating units of amino group bonded to carbonyl
group
, (n+4 rule)
3.6 amino acids per turn
right handed
◉ a helix cont..
Answer: two or more a helices intertwine to form coiled coil (ex.
keratin, fibrin, myosin)
hemoglobin high in a helix content
chymotrypsin lacks a helix
◉ b pleated sheet.
Answer: forms sheet by H bonding between amino and carboxyl
groups of dif peptide chains
parallel, antiparallel, mixed
extended polypeptide chains
◉ levels of protein structure.
Answer: primary- amino acid residues
secondary- alpha helix
tertiary- polypeptide chain
quaternary- assembled subunits
