BCH Exam 1
What type of covalent bond is responsible for holding together the secondary structure of proteins?
A) Disulfide bonds
D) Ionicbonds
B) Hydrogen bonds
E) None of the above
C) Amide bonds ANS:
what are the most abundant biological elements and what is their tier? ANS:C, N, O, H, 1st tier
what are the four types of unit molecules and what are the characteristics of each? ANS:1) Amino Acids-
contain an amino group and a carboxylic acid group, contains at least two ionizable groups (+ and -)
2) Carbohydrates- C(H2O)n, multiple -OH groups, convertible between closed (ring) and open forms
3) Nucleotides- 5 carbon sugar with N counting base ring, phosphate groups
4) Lipids- amphipathic (both polar and non polar), mostly hydrophobic
condensation is usually involved in what? ANS:modular construction of macromolecules
monomers in polymers are called what? ANS:residues
name the three types of polymers and the bonds that form them. ANS:1) proteins- polymers of Amino
Acids formed by peptide bonds/amino bonds
2) Nucleic acids- DNA or RNA, polymers of nucleotides formed by phophodiester bonds
3)polysaccharides- polymers of carbs joined by glycosidic bonds
What biological molecule cannot form polymers and why? ANS:lipids cannot form polymers because
they lack a common functional group to be joined by.
,G ANS:Gibbs free energy, energy able to be used on a system for work, -deltaG= spontaneous exergonic
energy released ,+deltaG= non spontaneous endergonic energy absorbed
H ANS:Enthalpy, heat of system, += energy absorbed, -= heat released
T ANS:entropy, disorder of the system
DeltaG=0 ANS:equilibrium, living systems are never at equilibrium, they work towards homeostasis
which is a stable condition of non equilibrium where deltaG is <0 (neg)
what type of reaction are most metabolic reactions? ANS:most metabolic reactions are oxidation-
reduction reactions
what are the three domains of life? ANS:bacteria, archaea and eukaryotes. prokaryotes are bacteria and
archaea
what is the principal of coupling reactions? ANS:Spontaneous biochemical reactions can be coupled
with unfavorable reactions to net negative change in free energy
metabolic reactions can be catalyzed by what? ANS:mostly proteins, some RNA
Amino functional group ANS:NH3+
deprotonated carboxylate functional group ANS:
carboxylate functional group ANS:
,amide functional group ANS:
hydroxyl functional group ANS:
Ester Functional group ANS:
Ether functional group ANS:
carbonyl functional group ANS:
sulfhydryl functional group ANS:
which of the following processes are spontaneous?
a) a reaction that occurs with any size decrease in enthalpy and any size increase in entropy
b) a reaction that occurs with a small increase in enthalpy and a large increase in entropy
c) a reaction that occurs with a large decrease in enthalpy and a small decrease in entropy
d) a reaction that occurs with any size increase in enthalpy and any size decrease in entropy ANS:A, B,
and C
Atomic orbital ANS:where we are most likely to find an electron. can combine to form hybrid orbitals
needed for molecular bonding interactions
Covalent bond ANS:strongest bond, two atoms share valence electrons, atomic orbitals overlap,
shortest bond length-> strongest bond
, ionic bond ANS:electrons transferred from one atom to another, low electronegativity of one atom is
complemented by high electronegativity of another atom, all ionic bonds have some degree of
covalence none are PURELY ionic
van der waals ANS:distance from nucleus to surface, orbitals as close as possible without overlapping,
no bond, dipole-dipole interactions-> between two polar molecules, london dispersion forces-> between
non polar molecules
Hydrogen bond ANS:electronegative element covalently bonded to H atom and electrostatically
attracted to second H atom.
about what percent of the human body is water? ANS:60%
what type of bonds is in one water molecule? how many sets of unpaired electron are there? ANS:two
hydrogens covalently bonded to an oxygen atom. too pairs of unpaired electrons causes water to be
polar,unequal sharing of electrons
what makes a hydrogen bond strong or weak? ANS:liner alignment makes a hydrogen bond stronger,
confers geometric constraints
how many other molecules can one H2O bind to by H bonding ? ANS:4
properties of water: ANS:highly cohesive, can bond to four other water molecules at one time by H
bonding,
what bonds are involved in Hydrogen bonding interaction? ANS:covalent and hydrogen bonds, H atom
tugged between two electronegative molecules
order the bond interactions from strongest to weakest ANS:1) covalent bond
What type of covalent bond is responsible for holding together the secondary structure of proteins?
A) Disulfide bonds
D) Ionicbonds
B) Hydrogen bonds
E) None of the above
C) Amide bonds ANS:
what are the most abundant biological elements and what is their tier? ANS:C, N, O, H, 1st tier
what are the four types of unit molecules and what are the characteristics of each? ANS:1) Amino Acids-
contain an amino group and a carboxylic acid group, contains at least two ionizable groups (+ and -)
2) Carbohydrates- C(H2O)n, multiple -OH groups, convertible between closed (ring) and open forms
3) Nucleotides- 5 carbon sugar with N counting base ring, phosphate groups
4) Lipids- amphipathic (both polar and non polar), mostly hydrophobic
condensation is usually involved in what? ANS:modular construction of macromolecules
monomers in polymers are called what? ANS:residues
name the three types of polymers and the bonds that form them. ANS:1) proteins- polymers of Amino
Acids formed by peptide bonds/amino bonds
2) Nucleic acids- DNA or RNA, polymers of nucleotides formed by phophodiester bonds
3)polysaccharides- polymers of carbs joined by glycosidic bonds
What biological molecule cannot form polymers and why? ANS:lipids cannot form polymers because
they lack a common functional group to be joined by.
,G ANS:Gibbs free energy, energy able to be used on a system for work, -deltaG= spontaneous exergonic
energy released ,+deltaG= non spontaneous endergonic energy absorbed
H ANS:Enthalpy, heat of system, += energy absorbed, -= heat released
T ANS:entropy, disorder of the system
DeltaG=0 ANS:equilibrium, living systems are never at equilibrium, they work towards homeostasis
which is a stable condition of non equilibrium where deltaG is <0 (neg)
what type of reaction are most metabolic reactions? ANS:most metabolic reactions are oxidation-
reduction reactions
what are the three domains of life? ANS:bacteria, archaea and eukaryotes. prokaryotes are bacteria and
archaea
what is the principal of coupling reactions? ANS:Spontaneous biochemical reactions can be coupled
with unfavorable reactions to net negative change in free energy
metabolic reactions can be catalyzed by what? ANS:mostly proteins, some RNA
Amino functional group ANS:NH3+
deprotonated carboxylate functional group ANS:
carboxylate functional group ANS:
,amide functional group ANS:
hydroxyl functional group ANS:
Ester Functional group ANS:
Ether functional group ANS:
carbonyl functional group ANS:
sulfhydryl functional group ANS:
which of the following processes are spontaneous?
a) a reaction that occurs with any size decrease in enthalpy and any size increase in entropy
b) a reaction that occurs with a small increase in enthalpy and a large increase in entropy
c) a reaction that occurs with a large decrease in enthalpy and a small decrease in entropy
d) a reaction that occurs with any size increase in enthalpy and any size decrease in entropy ANS:A, B,
and C
Atomic orbital ANS:where we are most likely to find an electron. can combine to form hybrid orbitals
needed for molecular bonding interactions
Covalent bond ANS:strongest bond, two atoms share valence electrons, atomic orbitals overlap,
shortest bond length-> strongest bond
, ionic bond ANS:electrons transferred from one atom to another, low electronegativity of one atom is
complemented by high electronegativity of another atom, all ionic bonds have some degree of
covalence none are PURELY ionic
van der waals ANS:distance from nucleus to surface, orbitals as close as possible without overlapping,
no bond, dipole-dipole interactions-> between two polar molecules, london dispersion forces-> between
non polar molecules
Hydrogen bond ANS:electronegative element covalently bonded to H atom and electrostatically
attracted to second H atom.
about what percent of the human body is water? ANS:60%
what type of bonds is in one water molecule? how many sets of unpaired electron are there? ANS:two
hydrogens covalently bonded to an oxygen atom. too pairs of unpaired electrons causes water to be
polar,unequal sharing of electrons
what makes a hydrogen bond strong or weak? ANS:liner alignment makes a hydrogen bond stronger,
confers geometric constraints
how many other molecules can one H2O bind to by H bonding ? ANS:4
properties of water: ANS:highly cohesive, can bond to four other water molecules at one time by H
bonding,
what bonds are involved in Hydrogen bonding interaction? ANS:covalent and hydrogen bonds, H atom
tugged between two electronegative molecules
order the bond interactions from strongest to weakest ANS:1) covalent bond
