BIOCHEM ONE EXAM STUDY GUIDE , MBC 3550 EXAM 1
STUDY GUIDE WITH COMPLETE SOLUTIONS
which types of covalent bonds are important in biochemistry? - ANSWER covalent bonds
have electrons shared between the atoms and both atoms contribute
coordination bonds: both electrons donated by the same atom, common with transition
metals (lewis base is donator, and acceptor is lewis acid)
Which types of bonds can carbon, nitrogen, hydrogen, oxygen form with each other? -
ANSWER polar covalent bonds
What types of bonds can oxygen and nitrogen form with metals such as Fe2+, Co2+ and
Zn2+? - ANSWER coordination bonds
Valency of carbon, nitrogen, and oxygen - ANSWER Carbon: 4 valence electrons
Nitrogen: 5 valence electrons
Oxygen: 6 valence electrons
Which types of bonds allow free rotation around the bond axis, which do? - ANSWER
single bonds allow rotation
double and triple bonds do not because too rigid
How does electronegativity influence the charge distribution between covalently bound
atoms? - ANSWER electronegative atoms can pull electrons toward them, creates dipole
moment
rank O, N, H and C according to their relative electronegativity - ANSWER most
electroneg O>N>C>H least electroneg
What is the general geometry of a ligands bound via single bonds to a carbon nitrogen
or oxygen atom? - ANSWER sp3 hybridized, tetrahedral, 109.5 degrees
What is the geometry if one of the bonds is a double bond? - ANSWER sp2 hybridized,
planar trigonal, 120 degrees
What is the difference between regular covalent bonds and coordination bonds in terms
of the origin of electrons forming the bond? - ANSWER in regular covalent bonds, each
atom donates an electron
in coordination covalent bonds, both electrons are donated by the same atom
How many ligands can Fe2+ accept via coordination bonds? - ANSWER 6 coordination
,bonds
What geometry do you expect if the maximum number of ligands are bound to Fe2+ via
coordination bonds? - ANSWER octahedral geometry
What is the meaning of the terms "configuration" and "conformation"? - ANSWER
configuration: stereoisomers, different chemical properties, different ways to arrange
the groups that are not possible to superimpose on each other
conformation: geometric rearrangement from rotation around single bond
Cis vs Trans Configuration - ANSWER cis: highest priority on same side of double bond
trans: highest priority on diff sides of double bond
Which functional groups are important in biochemistry? - ANSWER hydroxyl, methyl,
carbonyl, amino, phosphate, sulfhydryl
List four types of non-covalent interactions that are important in biochemistry? -
ANSWER Electrostatic / ionic
Hydrogen bonds
Van der Waals (become repulsive when you get close enough)
Hydrophobic interactions
List seven elementary interactions and describe how electrostatic interactions,
hydrogen bonds and van der Waals interactions are composed of more elementary
interactions. - ANSWER Charge-charge: full charges, force dependent on charge and
distance
Charge-dipole: one full charge, one dipole (partial charge)
Dipole-dipole: both permanent dipoles
Charge-induced dipole: one has full charge, dipole of other is induced (aka induction)
Dipole-induced dipole: one binding is permanent dipole, dipole of one is induced
Dispersion: both charges induced, one induces other, push and pull
Van der Waals repulsion: electron shells clash
Van der waals interactions are composite of dispersion and van der waals repulsion
Van der waals are in everything, as go up list each interaction can participate in ones
below
, What is the distance dependence of the Coulomb force? Is it always attractive? -
ANSWER as distance increases, force decreases (inversely proportional) no it can be
attractive or repulsive
What are the requirements for the formation of a hydrogen bond?Hydrogen bonds are
made up of which more elementary interactions? - ANSWER must have an h bond donor
and h bond acceptor, partially covalent character between donor + acceptor as
electrons weakly shared
contain H, N, O, or F
electrostatic interaction
The hydrogen bond and the van der Waals interaction are made up of which more
elementary interactions? - ANSWER H-bonding - dipole-dipole
Van der Waals - composite of dispersion and van der Waals repulsion
How rapidly is the van der Waals attraction (repulsion) potential falling off with
distance? - ANSWER only binds over short distances, 1/r^6
can become significant with large number of interacting atoms
optimal distance between atoms is sum of "van der waals radii" of two atoms
Which attractive elementary non-covalent interaction has the longest range, which the
shortest? - ANSWER longest range: charge-charge
shortest range: van der waals?
How are the radii of space filling models of atoms and molecules chosen? - ANSWER
Electronegativity - atom with greatest electronegativity pulls the strongest, having the
smaller radii
What is the relative strengths of non-covalent interactions as compared to covalent
bonds? - ANSWER covalent bonds are the strongest
STUDY GUIDE WITH COMPLETE SOLUTIONS
which types of covalent bonds are important in biochemistry? - ANSWER covalent bonds
have electrons shared between the atoms and both atoms contribute
coordination bonds: both electrons donated by the same atom, common with transition
metals (lewis base is donator, and acceptor is lewis acid)
Which types of bonds can carbon, nitrogen, hydrogen, oxygen form with each other? -
ANSWER polar covalent bonds
What types of bonds can oxygen and nitrogen form with metals such as Fe2+, Co2+ and
Zn2+? - ANSWER coordination bonds
Valency of carbon, nitrogen, and oxygen - ANSWER Carbon: 4 valence electrons
Nitrogen: 5 valence electrons
Oxygen: 6 valence electrons
Which types of bonds allow free rotation around the bond axis, which do? - ANSWER
single bonds allow rotation
double and triple bonds do not because too rigid
How does electronegativity influence the charge distribution between covalently bound
atoms? - ANSWER electronegative atoms can pull electrons toward them, creates dipole
moment
rank O, N, H and C according to their relative electronegativity - ANSWER most
electroneg O>N>C>H least electroneg
What is the general geometry of a ligands bound via single bonds to a carbon nitrogen
or oxygen atom? - ANSWER sp3 hybridized, tetrahedral, 109.5 degrees
What is the geometry if one of the bonds is a double bond? - ANSWER sp2 hybridized,
planar trigonal, 120 degrees
What is the difference between regular covalent bonds and coordination bonds in terms
of the origin of electrons forming the bond? - ANSWER in regular covalent bonds, each
atom donates an electron
in coordination covalent bonds, both electrons are donated by the same atom
How many ligands can Fe2+ accept via coordination bonds? - ANSWER 6 coordination
,bonds
What geometry do you expect if the maximum number of ligands are bound to Fe2+ via
coordination bonds? - ANSWER octahedral geometry
What is the meaning of the terms "configuration" and "conformation"? - ANSWER
configuration: stereoisomers, different chemical properties, different ways to arrange
the groups that are not possible to superimpose on each other
conformation: geometric rearrangement from rotation around single bond
Cis vs Trans Configuration - ANSWER cis: highest priority on same side of double bond
trans: highest priority on diff sides of double bond
Which functional groups are important in biochemistry? - ANSWER hydroxyl, methyl,
carbonyl, amino, phosphate, sulfhydryl
List four types of non-covalent interactions that are important in biochemistry? -
ANSWER Electrostatic / ionic
Hydrogen bonds
Van der Waals (become repulsive when you get close enough)
Hydrophobic interactions
List seven elementary interactions and describe how electrostatic interactions,
hydrogen bonds and van der Waals interactions are composed of more elementary
interactions. - ANSWER Charge-charge: full charges, force dependent on charge and
distance
Charge-dipole: one full charge, one dipole (partial charge)
Dipole-dipole: both permanent dipoles
Charge-induced dipole: one has full charge, dipole of other is induced (aka induction)
Dipole-induced dipole: one binding is permanent dipole, dipole of one is induced
Dispersion: both charges induced, one induces other, push and pull
Van der Waals repulsion: electron shells clash
Van der waals interactions are composite of dispersion and van der waals repulsion
Van der waals are in everything, as go up list each interaction can participate in ones
below
, What is the distance dependence of the Coulomb force? Is it always attractive? -
ANSWER as distance increases, force decreases (inversely proportional) no it can be
attractive or repulsive
What are the requirements for the formation of a hydrogen bond?Hydrogen bonds are
made up of which more elementary interactions? - ANSWER must have an h bond donor
and h bond acceptor, partially covalent character between donor + acceptor as
electrons weakly shared
contain H, N, O, or F
electrostatic interaction
The hydrogen bond and the van der Waals interaction are made up of which more
elementary interactions? - ANSWER H-bonding - dipole-dipole
Van der Waals - composite of dispersion and van der Waals repulsion
How rapidly is the van der Waals attraction (repulsion) potential falling off with
distance? - ANSWER only binds over short distances, 1/r^6
can become significant with large number of interacting atoms
optimal distance between atoms is sum of "van der waals radii" of two atoms
Which attractive elementary non-covalent interaction has the longest range, which the
shortest? - ANSWER longest range: charge-charge
shortest range: van der waals?
How are the radii of space filling models of atoms and molecules chosen? - ANSWER
Electronegativity - atom with greatest electronegativity pulls the strongest, having the
smaller radii
What is the relative strengths of non-covalent interactions as compared to covalent
bonds? - ANSWER covalent bonds are the strongest
