Biochemistry Questions - Principles of Biochemistry by
Lehninger| Revision exam fall 2024
Which of the following functional groups is specific to an alcohol? **** -OH
The main difference between prokaryotic and eukaryotic cells is the existence of _______ in
eukaryotes. **** the nucleus
Which of the following organelles does not have a double membrane?
a. mitochondrion
b. nucleus
c. endoplasmic reticulum
d. chloroplast **** c. endoplasmic reticulum
The heat of reaction at constant pressure is ________________. **** It's change in enthalpy
Organelles have which three attributes? **** Only in eukaryotic cells, membrane bound, have a
dedicated set of tasks.
The amino and carboxyl groups of amino acids react in a head-to-tail fashion, eliminating water,
and forming a covalent _______ linkage typically referred to as a _______ bond. **** amide,
peptide
pH=pKa when: **** [A-]=[HA]
*think pH=pKa + log(4/4) --> the log(1) equals 0, so all that's left in the equation is pH=pKa, but
only when the A- and HA are the same.
, Electrostatic forces
a. include ionic interactions between negatively charged carboxyl group and positively charged
amino groups.
b. average about 2kJ/mol in aqeous solutions.
c. typically are directional like hydrogen bonds
d. require a precise fit like van der Waals interactions **** a. include ionic interactions between
negatively charge carboxyl group and positively charged amino groups.
Weak forces that create constantly forming and breaking interactions at physiological
temperatures, but cumulatively impart stability to biological structures generated by the sum of
their collective interactions include all EXCEPT:
a. hydrogen bonds
b. van der Waals forces
c. ionic interactions
d. covalent bonds **** covalent bonds
Composed of peptidoglycan, a rigid framework of polysaccharide cross-linked by short peptide
chains, describes what structural feature of a prokaryotic cell? **** Cell wall
The unrivaled ability to form _______ hydrogen bonds per liquid water molecule is the source of
the strong intermolecular attractions unique to water. **** 4
In micelles... **** Hydrocarbon tails are excluded from the water into hydrophobic domains
If 0.1 moles of Na2HPO4 and 0.1 moles of NaH2PO4 are mixed in water, what is the resulting
pH? The pKa values for phosphoric acid are 2.1, 7.2, 12.4. **** 7.2
Which of the following pairs would be the best buffer at pH 10.0?
a. Acetic acid and sodium acetate (pKa=4.76)
b. H2CO3 and NaHCO3 (pKa values are 3.77 and 10.4)
c. Lactic acid and sodium lactate (pKa=3.86)
Lehninger| Revision exam fall 2024
Which of the following functional groups is specific to an alcohol? **** -OH
The main difference between prokaryotic and eukaryotic cells is the existence of _______ in
eukaryotes. **** the nucleus
Which of the following organelles does not have a double membrane?
a. mitochondrion
b. nucleus
c. endoplasmic reticulum
d. chloroplast **** c. endoplasmic reticulum
The heat of reaction at constant pressure is ________________. **** It's change in enthalpy
Organelles have which three attributes? **** Only in eukaryotic cells, membrane bound, have a
dedicated set of tasks.
The amino and carboxyl groups of amino acids react in a head-to-tail fashion, eliminating water,
and forming a covalent _______ linkage typically referred to as a _______ bond. **** amide,
peptide
pH=pKa when: **** [A-]=[HA]
*think pH=pKa + log(4/4) --> the log(1) equals 0, so all that's left in the equation is pH=pKa, but
only when the A- and HA are the same.
, Electrostatic forces
a. include ionic interactions between negatively charged carboxyl group and positively charged
amino groups.
b. average about 2kJ/mol in aqeous solutions.
c. typically are directional like hydrogen bonds
d. require a precise fit like van der Waals interactions **** a. include ionic interactions between
negatively charge carboxyl group and positively charged amino groups.
Weak forces that create constantly forming and breaking interactions at physiological
temperatures, but cumulatively impart stability to biological structures generated by the sum of
their collective interactions include all EXCEPT:
a. hydrogen bonds
b. van der Waals forces
c. ionic interactions
d. covalent bonds **** covalent bonds
Composed of peptidoglycan, a rigid framework of polysaccharide cross-linked by short peptide
chains, describes what structural feature of a prokaryotic cell? **** Cell wall
The unrivaled ability to form _______ hydrogen bonds per liquid water molecule is the source of
the strong intermolecular attractions unique to water. **** 4
In micelles... **** Hydrocarbon tails are excluded from the water into hydrophobic domains
If 0.1 moles of Na2HPO4 and 0.1 moles of NaH2PO4 are mixed in water, what is the resulting
pH? The pKa values for phosphoric acid are 2.1, 7.2, 12.4. **** 7.2
Which of the following pairs would be the best buffer at pH 10.0?
a. Acetic acid and sodium acetate (pKa=4.76)
b. H2CO3 and NaHCO3 (pKa values are 3.77 and 10.4)
c. Lactic acid and sodium lactate (pKa=3.86)
