drexel bio 209 final Exam comprehensive
questions and verified answers ACTUAL
EXAM 2025 TEST!! Graded A+ | 2026
EXAM UPDATE
weak interactions - ✔✔ANSWER✔✔-electrostatic
h bonding
van der waals
hydrophobic effect- tendency of non polar molecules to avoid contact with water in aqueous
solutions
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
conservation of protein domains - ✔✔ANSWER✔✔-humans and drosophilia share portions of the
same amino acid sequences
same protein domains can be found on different proteins
another name for protein assemblies - ✔✔ANSWER✔✔-polymer
ex. actin filaments
covalent bonds - ✔✔ANSWER✔✔-disulfide bonds help stabilize protein structure
non covalent bonds - ✔✔ANSWER✔✔-mediate specificity of binding between molecules
, kinetic properties of enzymes - ✔✔ANSWER✔✔-increase rate of biological reaction without altering
reaction equilibria
decrease activation energy of a reaction
accelerate reactions through stabilization of transition states
the enzyme active site
enzyme active site - ✔✔ANSWER✔✔-the catalytic site is 3-d
substrates bound to enzyme by electrostatic, h bonding, van der waals forces, and hydrophobic
interactions
catalytic sites form clefts crevices - ✔✔ANSWER✔✔-substrate bound within cleft
water excluded
nonpolar character enhances binding of substrate
enzyme substrate complex - ✔✔ANSWER✔✔-x ray crystallography, electron microscope and
spectrophotometry
enzymes derive power by bringing in favorable substrate orientation
leonor michaelis: reaction rate increases with increasing s until vmax is achieved
saturation effect - ✔✔ANSWER✔✔-ES complexes form until substrate saturation occurs at which
point no more substrate binding sites are available
reaction rates - ✔✔ANSWER✔✔-enzymes increase reaction rate by decreasing activation energy
posttranslational regulation enzyme activity - ✔✔ANSWER✔✔-allosteric regulation
covalent modification
proteolytic modification
allosteric regulation - ✔✔ANSWER✔✔-feedback inhibition
regulates levels of synthesized end product
questions and verified answers ACTUAL
EXAM 2025 TEST!! Graded A+ | 2026
EXAM UPDATE
weak interactions - ✔✔ANSWER✔✔-electrostatic
h bonding
van der waals
hydrophobic effect- tendency of non polar molecules to avoid contact with water in aqueous
solutions
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
conservation of protein domains - ✔✔ANSWER✔✔-humans and drosophilia share portions of the
same amino acid sequences
same protein domains can be found on different proteins
another name for protein assemblies - ✔✔ANSWER✔✔-polymer
ex. actin filaments
covalent bonds - ✔✔ANSWER✔✔-disulfide bonds help stabilize protein structure
non covalent bonds - ✔✔ANSWER✔✔-mediate specificity of binding between molecules
, kinetic properties of enzymes - ✔✔ANSWER✔✔-increase rate of biological reaction without altering
reaction equilibria
decrease activation energy of a reaction
accelerate reactions through stabilization of transition states
the enzyme active site
enzyme active site - ✔✔ANSWER✔✔-the catalytic site is 3-d
substrates bound to enzyme by electrostatic, h bonding, van der waals forces, and hydrophobic
interactions
catalytic sites form clefts crevices - ✔✔ANSWER✔✔-substrate bound within cleft
water excluded
nonpolar character enhances binding of substrate
enzyme substrate complex - ✔✔ANSWER✔✔-x ray crystallography, electron microscope and
spectrophotometry
enzymes derive power by bringing in favorable substrate orientation
leonor michaelis: reaction rate increases with increasing s until vmax is achieved
saturation effect - ✔✔ANSWER✔✔-ES complexes form until substrate saturation occurs at which
point no more substrate binding sites are available
reaction rates - ✔✔ANSWER✔✔-enzymes increase reaction rate by decreasing activation energy
posttranslational regulation enzyme activity - ✔✔ANSWER✔✔-allosteric regulation
covalent modification
proteolytic modification
allosteric regulation - ✔✔ANSWER✔✔-feedback inhibition
regulates levels of synthesized end product
