BCH210 MIDTERM| 213 QUESTIONS| WITH
COMPLETE SOLUTIONS
van der Waals correct answer: -weakest (short lives) but lots
could strengthen the bond
-furthest distance
-form as a result of hydrophobic interactions
-strength depends on the size of the atoms and the distance
between them
-cannot be closer than the Van der Waals contact distance or
else positively charged nuclei will repel each other (energy= 0)
Proteins correct answer: main action molecule of the cell (Most
chemical processes of the body are carried out by proteins)
-classified into many groups (antibodies, receptors, transporters
(move things within cell or across the membrane, hormones
(binds to signalling molecules and receptors), structural,
enzymes).
-made up of amino acids (monomers) linked by peptide/amide
bonds through a condensation reaction
-made up of many bonds to form its final structure and help the
protein perform its function
-they play a variety of roles including catalysis (ie enzyme),
structure and recognition (binding to other proteins or molecules
like an antibody)
-each protein could play multiple roles at once (ie glycoproteins
could act as a membrane protein, transporter and recognition
molecule). The role is plays changes depending on the molecule
its interacting with
,-most hormones are signalling molecules but not all signalling
molecules are hormones (ie Neurotransmitter)
-receptors are recognition molecules but not all recognition
molecules are receptors
-not all proteins could be enzymes- some are hormones for
example
-not all enzymes are proteins- some are RNA based
why is water polar but uncharged correct answer: -bc the
Hydrogen has a partial positive charge and the oxygen has a
partial negative charge. This cancels out, making the overall
charge of the molecule 0
-the oxygen has a greater pull on the electrons because its more
electronegative so theres an unequal sharing
water in reactions correct answer: -because water is an excellent
nucleophile (attack chemical bonds and donate elections to
create new bonds) allows it to participate in hydrolysis and
condensation reactions
Hydrolysis- adding water to break a bond
Condensation- lose water to form a bond
-proteins may fold to exclude water, preventing these reactions
from happening while maximizing the number of interactions of
hydrophilic functional groups with water for solubility so the
protein stays in solution
The hydrophobic effect correct answer: -the exclusion of water
leads to an increase in the entropy of water molecules obeying
the 2nd law of thermodynamics which states that entropy is
always increasing in the system
,-when non polar molecules are put in water, they will form
bonds with one another (aggregate) and avoid water, forming the
structure of the macromolecule, creating more order within the
protein and more disorder (more entropy) with the water
because water is released from the molecule
-entropy of the system (water) is increasing
-entropy of the molecule (decrease) because more bonds are
forming between the non polar molecules
-when these non polar molecules interact, Van der Waals bonds
form
-the main driving force of macromolecular structure
protein folding and what bonds drives protein folding the most
correct answer: -hydrophobic residues (inside) away from water
and interact with each other
-hydrophilic residues (outside) facing water- keeps the molecule
in solution
-difference is due to the functional group properties that make
up the residues
-the hydrophobic regions interact with each other while the
hydrophilic regions react to the external environment (water)
bonds drives protein folding the most- h bonding and
hydrophobic effect. Once these happen, you see the other bonds
types of non-covalent bonds correct answer: ionic, hydrogen,
van der waals, hydrophobic interactions (not a bond)
, -reversible because they are less strong- important for the
protein's final structure (formation through side chains of amino
acids which bring different parts of the protein together)
covalent bonds correct answer: -would not exist if there weren't
any protein enzymes to makes these bonds
-strongest and shortest (irreversible)
-equal electron sharing between 2 atoms (2 non-metals)
-ie phosphodiester bonds, glycosidic bonds, peptide/amide
bonds)
Ionic bonds correct answer: -strength of bonds depends on the
polarity of the two atoms
-charged interactions between (+) and (-)
-also known as salt bridges
-unequal distribution of elections
H bonds correct answer: -type of ionic bonds/salt bridge
-H bond to a highly electronegative ion (halogen)
-strong, attractive non covalent forces
-strength is proportional to the polarity of the H bond acceptor
and donor (the more electronegative atom the H is binding to,
the stronger the H bond)
-bonds can occur between molecules or within parts of a single
molecule
-seen through base pairing along 2 strands of DNA to hold the
strands together
COMPLETE SOLUTIONS
van der Waals correct answer: -weakest (short lives) but lots
could strengthen the bond
-furthest distance
-form as a result of hydrophobic interactions
-strength depends on the size of the atoms and the distance
between them
-cannot be closer than the Van der Waals contact distance or
else positively charged nuclei will repel each other (energy= 0)
Proteins correct answer: main action molecule of the cell (Most
chemical processes of the body are carried out by proteins)
-classified into many groups (antibodies, receptors, transporters
(move things within cell or across the membrane, hormones
(binds to signalling molecules and receptors), structural,
enzymes).
-made up of amino acids (monomers) linked by peptide/amide
bonds through a condensation reaction
-made up of many bonds to form its final structure and help the
protein perform its function
-they play a variety of roles including catalysis (ie enzyme),
structure and recognition (binding to other proteins or molecules
like an antibody)
-each protein could play multiple roles at once (ie glycoproteins
could act as a membrane protein, transporter and recognition
molecule). The role is plays changes depending on the molecule
its interacting with
,-most hormones are signalling molecules but not all signalling
molecules are hormones (ie Neurotransmitter)
-receptors are recognition molecules but not all recognition
molecules are receptors
-not all proteins could be enzymes- some are hormones for
example
-not all enzymes are proteins- some are RNA based
why is water polar but uncharged correct answer: -bc the
Hydrogen has a partial positive charge and the oxygen has a
partial negative charge. This cancels out, making the overall
charge of the molecule 0
-the oxygen has a greater pull on the electrons because its more
electronegative so theres an unequal sharing
water in reactions correct answer: -because water is an excellent
nucleophile (attack chemical bonds and donate elections to
create new bonds) allows it to participate in hydrolysis and
condensation reactions
Hydrolysis- adding water to break a bond
Condensation- lose water to form a bond
-proteins may fold to exclude water, preventing these reactions
from happening while maximizing the number of interactions of
hydrophilic functional groups with water for solubility so the
protein stays in solution
The hydrophobic effect correct answer: -the exclusion of water
leads to an increase in the entropy of water molecules obeying
the 2nd law of thermodynamics which states that entropy is
always increasing in the system
,-when non polar molecules are put in water, they will form
bonds with one another (aggregate) and avoid water, forming the
structure of the macromolecule, creating more order within the
protein and more disorder (more entropy) with the water
because water is released from the molecule
-entropy of the system (water) is increasing
-entropy of the molecule (decrease) because more bonds are
forming between the non polar molecules
-when these non polar molecules interact, Van der Waals bonds
form
-the main driving force of macromolecular structure
protein folding and what bonds drives protein folding the most
correct answer: -hydrophobic residues (inside) away from water
and interact with each other
-hydrophilic residues (outside) facing water- keeps the molecule
in solution
-difference is due to the functional group properties that make
up the residues
-the hydrophobic regions interact with each other while the
hydrophilic regions react to the external environment (water)
bonds drives protein folding the most- h bonding and
hydrophobic effect. Once these happen, you see the other bonds
types of non-covalent bonds correct answer: ionic, hydrogen,
van der waals, hydrophobic interactions (not a bond)
, -reversible because they are less strong- important for the
protein's final structure (formation through side chains of amino
acids which bring different parts of the protein together)
covalent bonds correct answer: -would not exist if there weren't
any protein enzymes to makes these bonds
-strongest and shortest (irreversible)
-equal electron sharing between 2 atoms (2 non-metals)
-ie phosphodiester bonds, glycosidic bonds, peptide/amide
bonds)
Ionic bonds correct answer: -strength of bonds depends on the
polarity of the two atoms
-charged interactions between (+) and (-)
-also known as salt bridges
-unequal distribution of elections
H bonds correct answer: -type of ionic bonds/salt bridge
-H bond to a highly electronegative ion (halogen)
-strong, attractive non covalent forces
-strength is proportional to the polarity of the H bond acceptor
and donor (the more electronegative atom the H is binding to,
the stronger the H bond)
-bonds can occur between molecules or within parts of a single
molecule
-seen through base pairing along 2 strands of DNA to hold the
strands together
