BMB 401 Exam 1 – Study Guide, Practice Questions & Revision Notes
Persons with chronic bronchitis have elevated CO2 in their lungs,
decreasing the [H+] and the pH of the blood. True or False - ✔✔False
Which atom does NOT commonly form hydrogen bonds between or within biological
molecules?
Oxygen
Hydrogen
Carbon
Nitrogen - ✔✔CARBON does NOT form hydrogen bonds
FON
Which statement about hydrogen bonds is false
-They only occur between water molecules
- They are weak compared with covalent bonds
- They cause acid-base reactions in aqueous solutions to be very rapid. - ✔✔They only occur
between water molecules (False)
Nonpolar compounds - ✔✔interfere with the hydrogen bonding among H2O molecules
Carbonic acid (H2CO3) is formed from dissolved (aq) carbon dioxide and water, in a reversible
reaction:
,CO2 + H2O = H2CO3
The equilibrium constant for this reaction is - ✔✔[H2CO3] / [CO2][H2O]
What is the actual function of a buffer system such as acetate/acetic acid? - ✔✔to maintain a
constant pH in the event that the concentration of an acid or base increases
Which amino acid has three pKa values - ✔✔cysteine
T/F Ionic bond strength is inversely proportional to the charge on the ions involves in the ionic
interaction - ✔✔FALSE
T/F Ionic bond strength is inversely proportional to the dielectric constant of the solvent in
which the ions are found - ✔✔TRUE
4 classes of macromolecules - ✔✔lipids, proteins, nucleic acids, carbohydrates
List the weak, non-covalent forces involved in intermolecular interactions - ✔✔hydrophobic
interactions
disulfide bonds
hydrogen bonds
Threonine - ✔✔polar, aliphatic
T/F The chiral amino acids found in proteins are in the L-configuration - ✔✔True
What is invariant in amino acids - ✔✔- hydrogen covalently linked to the alpha carbon
,- alpha-carbon
- alpha-amino group covalently linked to the alpha carbon
- alpha-carboxyl group covalently linked to the alpha carbon
Which amino acid is chiral
-lycine
-glutamine
-alanine
-glycine - ✔✔Glycine
Which AA's will have a positive charge at physiological pH - ✔✔Arginine
Lysine
If aspartate was at the C-terminus of a peptide at pH 3 - ✔✔The aspartate R-group would have
a neutral charge, the aspartate alpha-carboxyl group would have a negative charge, and the
aspartate alpha-amino group would have a neutral charge.
The charges on aspartate would be 0 for the R-group because the pH is below the acid's pKa by
one PH unit and -1 for the terminal alpha-carboxyl group, because the pH is above the acid's
pKa by one pH unit. The alpha-amino group is in a peptide bond )which is an amide and so
cannot ionize in these conditions) so the alpha-amino group will be normal.
At what pH could 50% of the R-groups of lysine in a solution of free lysine in aqueous solution
have +1 charge and 50% have a neutral charge? - ✔✔At pH 10, the R-group would be 50% +1
and 50% neutral. The alpha amino group would have a charge of +1. The alpha-carboxylic acid
group have a charge of 0.
T/F Endergonic reactions are often coupled to exergonic reactions - ✔✔True
, T/F Anabolism describes metabolic processes that breakdown macromolecules into smaller
building blocks - ✔✔FALSE, this is catabolism
All living things on earth ultimately derive their energy from the sun - ✔✔TRUE
All describe eukaryotes - ✔✔- contains nucleus and membrane bound organelles
-can be single-cell organisms
- includes all organisms from eukarya domain
T/F Replication, transcription, and translation all require a primer. - ✔✔False. Translation does
not use a primer
T/F Replication and transcription require nucleotides and a polymerase, but translation only
requires a polymerase - ✔✔False.
T/F The product of transcription is an RNA molecule. - ✔✔True
T/F RNA can be reverse transcribed into DNA, but protein cannot be converted to RNA. -
✔✔True
T/F The 3' hydroxyl on the ribose sugar sometimes catalyzes self-cleavage of RNA molecules. -
✔✔False!
2' hydroxyl catalyzes cleavage. The 3' OH is nucleophilic and is used to add nucleotides in
polymerase reaction
Persons with chronic bronchitis have elevated CO2 in their lungs,
decreasing the [H+] and the pH of the blood. True or False - ✔✔False
Which atom does NOT commonly form hydrogen bonds between or within biological
molecules?
Oxygen
Hydrogen
Carbon
Nitrogen - ✔✔CARBON does NOT form hydrogen bonds
FON
Which statement about hydrogen bonds is false
-They only occur between water molecules
- They are weak compared with covalent bonds
- They cause acid-base reactions in aqueous solutions to be very rapid. - ✔✔They only occur
between water molecules (False)
Nonpolar compounds - ✔✔interfere with the hydrogen bonding among H2O molecules
Carbonic acid (H2CO3) is formed from dissolved (aq) carbon dioxide and water, in a reversible
reaction:
,CO2 + H2O = H2CO3
The equilibrium constant for this reaction is - ✔✔[H2CO3] / [CO2][H2O]
What is the actual function of a buffer system such as acetate/acetic acid? - ✔✔to maintain a
constant pH in the event that the concentration of an acid or base increases
Which amino acid has three pKa values - ✔✔cysteine
T/F Ionic bond strength is inversely proportional to the charge on the ions involves in the ionic
interaction - ✔✔FALSE
T/F Ionic bond strength is inversely proportional to the dielectric constant of the solvent in
which the ions are found - ✔✔TRUE
4 classes of macromolecules - ✔✔lipids, proteins, nucleic acids, carbohydrates
List the weak, non-covalent forces involved in intermolecular interactions - ✔✔hydrophobic
interactions
disulfide bonds
hydrogen bonds
Threonine - ✔✔polar, aliphatic
T/F The chiral amino acids found in proteins are in the L-configuration - ✔✔True
What is invariant in amino acids - ✔✔- hydrogen covalently linked to the alpha carbon
,- alpha-carbon
- alpha-amino group covalently linked to the alpha carbon
- alpha-carboxyl group covalently linked to the alpha carbon
Which amino acid is chiral
-lycine
-glutamine
-alanine
-glycine - ✔✔Glycine
Which AA's will have a positive charge at physiological pH - ✔✔Arginine
Lysine
If aspartate was at the C-terminus of a peptide at pH 3 - ✔✔The aspartate R-group would have
a neutral charge, the aspartate alpha-carboxyl group would have a negative charge, and the
aspartate alpha-amino group would have a neutral charge.
The charges on aspartate would be 0 for the R-group because the pH is below the acid's pKa by
one PH unit and -1 for the terminal alpha-carboxyl group, because the pH is above the acid's
pKa by one pH unit. The alpha-amino group is in a peptide bond )which is an amide and so
cannot ionize in these conditions) so the alpha-amino group will be normal.
At what pH could 50% of the R-groups of lysine in a solution of free lysine in aqueous solution
have +1 charge and 50% have a neutral charge? - ✔✔At pH 10, the R-group would be 50% +1
and 50% neutral. The alpha amino group would have a charge of +1. The alpha-carboxylic acid
group have a charge of 0.
T/F Endergonic reactions are often coupled to exergonic reactions - ✔✔True
, T/F Anabolism describes metabolic processes that breakdown macromolecules into smaller
building blocks - ✔✔FALSE, this is catabolism
All living things on earth ultimately derive their energy from the sun - ✔✔TRUE
All describe eukaryotes - ✔✔- contains nucleus and membrane bound organelles
-can be single-cell organisms
- includes all organisms from eukarya domain
T/F Replication, transcription, and translation all require a primer. - ✔✔False. Translation does
not use a primer
T/F Replication and transcription require nucleotides and a polymerase, but translation only
requires a polymerase - ✔✔False.
T/F The product of transcription is an RNA molecule. - ✔✔True
T/F RNA can be reverse transcribed into DNA, but protein cannot be converted to RNA. -
✔✔True
T/F The 3' hydroxyl on the ribose sugar sometimes catalyzes self-cleavage of RNA molecules. -
✔✔False!
2' hydroxyl catalyzes cleavage. The 3' OH is nucleophilic and is used to add nucleotides in
polymerase reaction
