Chemical and Physical Foundations of Biological Systems
Questions With Complete Solutions
Acetyl CoA is what kind of molecule? (e.g. is it an alcohol,
carboxylic acid, etc?) Correct Answer It's a thioester
At what speed does a fluid become turbulent? What's the
Reynolds number for blood? Correct Answer +Nr is reynolds
number (2000 for blood)
+eta is viscosity
+D is diameter (note that D = 2r)
+rho is density of fluid
Atmospheres vs. Pascals Correct Answer 1atm = 101,325 Pa
Describe a relationship between macroscopic and microscopic
quantities of moving, monatomic gas particles Correct Answer
Kinetic - molecular theory of gases
KEavg = 3/2*k_b*T = U_total (where U_total is total internal
energy)
3/2PV = 3/2N*k_b*T = 3/2*n*R*T = U
Describe how Gabriel Synthesis produces an alpha amino acid
Correct Answer Start with N-phalimidomalonic ester
,1. Alkylate by adding a Base and R-X group
2. Hydrolize by adding H3O+
3. Add heat to decarboxylate, forming final product
Describe how Strecker Synthesis produces an alpha amino acid
Correct Answer Start with aldehyde and ammonia
1. React with acid to form imine and water
2. React with acid and KCN to add another C (the eventually
COOH carbon)
3. Add acid to remove N and protonate the NH3+
Describe how the following disaccharides are different:
1. Lactose
2. Maltose
3. Sucrose Correct Answer 1. Lactose - beta 1,4-glycosidic
bond between glucose and galactose
2. Maltose - alpha 1,4-glycosidic bond between glucose and
glucose
3. Sucrose - alpha glycosidic bonds between anomeric carbon of
glucose (a pyranose) and fructose (a furanose)
Describe how the following polysaccharides are different:
1. Cellulose
2. Starch
3. Glycogen Correct Answer 1. Celluose - has beta 1,4-
glycosidic bonds
2. Starch - has alpha 1,4-glycosidic bonds
3. Glycogen - similar to starch, but with additional 1,6-
glycosidic bonds branching off
Describe some logarithmic approximations Correct Answer
,Describe the boiling point and solubility in water of
ketones/aldehydes Correct Answer Boiling point: alkanes <
aldehydes/ketones < alcohols
Solubility: soluble in water because of hydrogen bonds
Note: ACETONE IS SOLUBLE IN WATER/other polar
solvents
Describe the equivalence capacitance of capacitance in
PARALLEL Correct Answer Ceq = C1 + C2 + C3
True because SAME VOLTAGE across parallel capacitors and
SUM of charges Q across capacitors add up to total Q on all
plates
Tip: Think of like a giant capacitor
Describe the equivalence capacitance of capacitance in SERIES
Correct Answer 1/Ceq = 1/C1 + 1/C2 + 1/C3 .....
, True because the stored charge Q is the SAME on all capacitors
and voltages across all capacitors SUM to voltage of battery
added to charge circuit
Describe the most important IR wavenumbers to know. What
does each correspond to? Correct Answer IR:
Broad peak at 3300 cm-1 > O-H
Carboxylic acids > 3000 cm-1
Sharp peak at 3300 cm-1 > N-H
Sharp peak at 1750 cm-1 > C=O
Describe the most important NMR ppm (parts per million)
values to know. What does each correspond to? Correct Answer
NMR:
Hydrogens on sp3 carbons > 0 to 3 ppm
Hydrogens on sp2 carbons > 4.6 to 6.0 ppm
Hydrogens on sp carbons > 2.0 to 3.0 ppm
Aldehyde Hydrogens > 9 to 10 ppm
Carboxylic acids Hydrogens > 10.5 to 12 ppm
Aromatics Hydrogens > 6.0 to 8.5 ppm
Describe the structure of a phospholipid. Where are they most
commonly found? Correct Answer phosphate in a diester
bonded with two other FA chains and an R group. Found in cell
membranes
Describe the structure of a sphingolipid. Where are they most
commonly found? Correct Answer Sphingosine bonded to
phosphate group. Commonly found in myelin sheath of nerve
axons
Questions With Complete Solutions
Acetyl CoA is what kind of molecule? (e.g. is it an alcohol,
carboxylic acid, etc?) Correct Answer It's a thioester
At what speed does a fluid become turbulent? What's the
Reynolds number for blood? Correct Answer +Nr is reynolds
number (2000 for blood)
+eta is viscosity
+D is diameter (note that D = 2r)
+rho is density of fluid
Atmospheres vs. Pascals Correct Answer 1atm = 101,325 Pa
Describe a relationship between macroscopic and microscopic
quantities of moving, monatomic gas particles Correct Answer
Kinetic - molecular theory of gases
KEavg = 3/2*k_b*T = U_total (where U_total is total internal
energy)
3/2PV = 3/2N*k_b*T = 3/2*n*R*T = U
Describe how Gabriel Synthesis produces an alpha amino acid
Correct Answer Start with N-phalimidomalonic ester
,1. Alkylate by adding a Base and R-X group
2. Hydrolize by adding H3O+
3. Add heat to decarboxylate, forming final product
Describe how Strecker Synthesis produces an alpha amino acid
Correct Answer Start with aldehyde and ammonia
1. React with acid to form imine and water
2. React with acid and KCN to add another C (the eventually
COOH carbon)
3. Add acid to remove N and protonate the NH3+
Describe how the following disaccharides are different:
1. Lactose
2. Maltose
3. Sucrose Correct Answer 1. Lactose - beta 1,4-glycosidic
bond between glucose and galactose
2. Maltose - alpha 1,4-glycosidic bond between glucose and
glucose
3. Sucrose - alpha glycosidic bonds between anomeric carbon of
glucose (a pyranose) and fructose (a furanose)
Describe how the following polysaccharides are different:
1. Cellulose
2. Starch
3. Glycogen Correct Answer 1. Celluose - has beta 1,4-
glycosidic bonds
2. Starch - has alpha 1,4-glycosidic bonds
3. Glycogen - similar to starch, but with additional 1,6-
glycosidic bonds branching off
Describe some logarithmic approximations Correct Answer
,Describe the boiling point and solubility in water of
ketones/aldehydes Correct Answer Boiling point: alkanes <
aldehydes/ketones < alcohols
Solubility: soluble in water because of hydrogen bonds
Note: ACETONE IS SOLUBLE IN WATER/other polar
solvents
Describe the equivalence capacitance of capacitance in
PARALLEL Correct Answer Ceq = C1 + C2 + C3
True because SAME VOLTAGE across parallel capacitors and
SUM of charges Q across capacitors add up to total Q on all
plates
Tip: Think of like a giant capacitor
Describe the equivalence capacitance of capacitance in SERIES
Correct Answer 1/Ceq = 1/C1 + 1/C2 + 1/C3 .....
, True because the stored charge Q is the SAME on all capacitors
and voltages across all capacitors SUM to voltage of battery
added to charge circuit
Describe the most important IR wavenumbers to know. What
does each correspond to? Correct Answer IR:
Broad peak at 3300 cm-1 > O-H
Carboxylic acids > 3000 cm-1
Sharp peak at 3300 cm-1 > N-H
Sharp peak at 1750 cm-1 > C=O
Describe the most important NMR ppm (parts per million)
values to know. What does each correspond to? Correct Answer
NMR:
Hydrogens on sp3 carbons > 0 to 3 ppm
Hydrogens on sp2 carbons > 4.6 to 6.0 ppm
Hydrogens on sp carbons > 2.0 to 3.0 ppm
Aldehyde Hydrogens > 9 to 10 ppm
Carboxylic acids Hydrogens > 10.5 to 12 ppm
Aromatics Hydrogens > 6.0 to 8.5 ppm
Describe the structure of a phospholipid. Where are they most
commonly found? Correct Answer phosphate in a diester
bonded with two other FA chains and an R group. Found in cell
membranes
Describe the structure of a sphingolipid. Where are they most
commonly found? Correct Answer Sphingosine bonded to
phosphate group. Commonly found in myelin sheath of nerve
axons
