BPS 2110 Midterm 2 Exam Questions And Correct Answers
Use of isostere - ANSWER functional group replacements
isostere - ANSWER groups of atoms with similar sterics and electronics.
give similar biological activity
classical isostere - ANSWER atoms or groups that have the same valency and similar
size
help determine if groups are important for binding
EXAMPLE: OH = F, Cl, SH, NH2, CH3
Non-classical isosteres - ANSWER atoms or groups that have similar chemical
properties (look for similar pka values)
differ in electronics and sterics
EXERCISE: OH = SO3H, PO4H, tetrazol
Chain extension/contraction - ANSWER vary linker size to optimize interactions (binding)
of groups at two ends
add of remove carbon atoms
Ring expansion/contraction - ANSWER Vary ring size to improve overlap of binding
groups with their binding regions
use heteroatoms
structure simplification - ANSWER remove parts that don't affect potency
remove stereocenters
stereocenters - ANSWER a carbon with four different atoms or groups of atoms bonded
to it, aka asymmetric carbon or chiral center
,avoid; they make manufacturing more complex and requires more testing
Raceimates - ANSWER mixture of both enantiomers (consider enantiomers are separate
compounds)
easier to make and test
only test single enantiomers once you have a positive test
Pharmacophore - ANSWER The part of the molecule responsible for a drug's biological
effect
that part of the drug which can come into physical contact with the biomolecule
Antibiotic - ANSWER selective poison for microbes and bacteria
have biggest impact on quality of life and life span
Paul Erlich - ANSWER discovered compound that was selectively toxic to bacteria not
humans
trypan red - ANSWER first drug that worked against trypanosomes which caused
sleeping sickness
trypan red dyes trypanosomes but leaves RBCs alone
Erlich found a biochemical difference between cells that took up dye and those that
didn't
Salvarsan 606 - ANSWER treatment for syphillis
,replaced N atoms in dye structure with As in drug
poor product because it was very insoluble in water which meant it required a large
dose. if you injected it too fast, the drug precipitated from veins and stopped circulation.
If injected too deep, it caused necrosis
Prontosil - ANSWER Dye that contains sulfa molecule; its use began the practice of
treating diseases with drugs
only effective in vivo
Sulfa drug mechanism of action - ANSWER interferes with bacterial growth
this inhibits coenzyme F synthesis which stops the growth of bacteria SN2 Rxn
we dont naturally have CoF in our body so the drug is selective to only bacteria
Sulfonamides - ANSWER competitive inhibitors of PABA
binds to active site of enzyme and prevents rxn
PABA vs Sulfonamide - ANSWER both deprotonated at pH 7.4 therefore have the same
charge and binding pattern
blocking enzyme function - ANSWER S + E = ES --> P + E
E + I = EI and no product
Competitive inhibitor - ANSWER ideally you want an inhibitor that can bind better than
the enzyme than the natural substrate can
Common Structural Modification of Sulfa Drug - ANSWER example of SAR
, add heterocycle to the NH group
penicillins - ANSWER 80% of all antibiotics
>30,000 synthesized
>100 sold as drugs
Flemming, Florey, and Chain - ANSWER FLEMMING:
- contaminated culture and noticed mold was preventing bacteria growth
FLOREY & CHAIN:
- isolated, identified, tested penicillin
Penicillin mode of action - ANSWER Antibiotic that acts through inhibition of cell wall
synthesis.
Selective only to bacteria because they have a cell wall unlike humans
Origin of osmotic pressure - ANSWER high concentration inside the cell and low
concentration outside the cell created concentration gradient
since we cant move stuff from inside to out, we bring water inside to dilute
concentration inside the cell.
by bringing water in we raise internal pressure
Cell wall formation - ANSWER two polysaccharride chains come together where their
peptide chains connect via peptide cross links
cross linking - ANSWER method of strengthening structures.
make links between strands
Use of isostere - ANSWER functional group replacements
isostere - ANSWER groups of atoms with similar sterics and electronics.
give similar biological activity
classical isostere - ANSWER atoms or groups that have the same valency and similar
size
help determine if groups are important for binding
EXAMPLE: OH = F, Cl, SH, NH2, CH3
Non-classical isosteres - ANSWER atoms or groups that have similar chemical
properties (look for similar pka values)
differ in electronics and sterics
EXERCISE: OH = SO3H, PO4H, tetrazol
Chain extension/contraction - ANSWER vary linker size to optimize interactions (binding)
of groups at two ends
add of remove carbon atoms
Ring expansion/contraction - ANSWER Vary ring size to improve overlap of binding
groups with their binding regions
use heteroatoms
structure simplification - ANSWER remove parts that don't affect potency
remove stereocenters
stereocenters - ANSWER a carbon with four different atoms or groups of atoms bonded
to it, aka asymmetric carbon or chiral center
,avoid; they make manufacturing more complex and requires more testing
Raceimates - ANSWER mixture of both enantiomers (consider enantiomers are separate
compounds)
easier to make and test
only test single enantiomers once you have a positive test
Pharmacophore - ANSWER The part of the molecule responsible for a drug's biological
effect
that part of the drug which can come into physical contact with the biomolecule
Antibiotic - ANSWER selective poison for microbes and bacteria
have biggest impact on quality of life and life span
Paul Erlich - ANSWER discovered compound that was selectively toxic to bacteria not
humans
trypan red - ANSWER first drug that worked against trypanosomes which caused
sleeping sickness
trypan red dyes trypanosomes but leaves RBCs alone
Erlich found a biochemical difference between cells that took up dye and those that
didn't
Salvarsan 606 - ANSWER treatment for syphillis
,replaced N atoms in dye structure with As in drug
poor product because it was very insoluble in water which meant it required a large
dose. if you injected it too fast, the drug precipitated from veins and stopped circulation.
If injected too deep, it caused necrosis
Prontosil - ANSWER Dye that contains sulfa molecule; its use began the practice of
treating diseases with drugs
only effective in vivo
Sulfa drug mechanism of action - ANSWER interferes with bacterial growth
this inhibits coenzyme F synthesis which stops the growth of bacteria SN2 Rxn
we dont naturally have CoF in our body so the drug is selective to only bacteria
Sulfonamides - ANSWER competitive inhibitors of PABA
binds to active site of enzyme and prevents rxn
PABA vs Sulfonamide - ANSWER both deprotonated at pH 7.4 therefore have the same
charge and binding pattern
blocking enzyme function - ANSWER S + E = ES --> P + E
E + I = EI and no product
Competitive inhibitor - ANSWER ideally you want an inhibitor that can bind better than
the enzyme than the natural substrate can
Common Structural Modification of Sulfa Drug - ANSWER example of SAR
, add heterocycle to the NH group
penicillins - ANSWER 80% of all antibiotics
>30,000 synthesized
>100 sold as drugs
Flemming, Florey, and Chain - ANSWER FLEMMING:
- contaminated culture and noticed mold was preventing bacteria growth
FLOREY & CHAIN:
- isolated, identified, tested penicillin
Penicillin mode of action - ANSWER Antibiotic that acts through inhibition of cell wall
synthesis.
Selective only to bacteria because they have a cell wall unlike humans
Origin of osmotic pressure - ANSWER high concentration inside the cell and low
concentration outside the cell created concentration gradient
since we cant move stuff from inside to out, we bring water inside to dilute
concentration inside the cell.
by bringing water in we raise internal pressure
Cell wall formation - ANSWER two polysaccharride chains come together where their
peptide chains connect via peptide cross links
cross linking - ANSWER method of strengthening structures.
make links between strands
