BIOL 101 QUESTIONS AND ANSWERS EXAM LATEST
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Relationship of structure and function of macromolecules
Structure determines function
(ex. lysosyme - bacteria fit precisely into cleft)
ionic bond
attraction between opposite electrical charges at specific sites
--weak interaction
--non directional
hydrogen bond
bond formed when two chemical groups share a hydrogen
--O is more electronegative than H, pulls more strongly on electrons, giving O a partial
negative charge and H and partial positive charge
--directional!
Polar molecules
molecules with fully charged or partially charged atoms
--ionic and H bonds form between these types of molecules
hydrophobic interaction
nonpolar, uncharged atoms surfaces on macromolecules have no H bond
donors/acceptors and no charge to form ionic bonds; and so tend to aggregate together
at the interior of the molecule
van der Waals interaction
brief interactions that occur b/c of random variations in electron distribution in one
molecule creates a dipole, which causes opposite charge distribution in a nearby
molecule -- leads to a temporary partial charge attraction
Covalent bond
sharing of electron pairs; strongest interaction (by a LOT)
Strength of noncovalent interactions
Ionic ------------------------------- 3-7
H bond -----------------------------3-7
Hydrophobic interaction---------1-2
van der Waals interaction-------1
Ionic bond (photo)
HO
l ll
N -- H(+ -)O -- C--
l
H
Hydrogen bond (photo)
H
l (8+) (8-) l
-- N -- H ....... O = C --
Hydrophobic Interaction (photo)
, HHHH
ll\l
-- C -- C -- H C -- C
ll/ll
HHHHH
van der Waals forces (photo)
HH
... \ /
H--H :::::: C
.. / \
HH
characteristics/functions of the four noncovalent interactions
--individually too weak to allow binding
--working together, can be strong enough for binding, however still weak enough to be
reversible
--surface interactions allow macromolecules to reversibly bind substrates
Protein
macromolecule - long chain of amino acids, linked by covalent bonds -- "polypeptide"
--each type of protein uses a unique sequence of amino acids, each protein has unique
shape and function
amino acid
protein monomer
consists of:
--amino group (NH3+)
--carboxl group (COO-)
--H
--R side chain
all attached to the alpha carbon
R chain
20 types - determine type of amino acid
peptide bond
covalent bond between amino acids
(between carboxl and amine groups of two amino acids)
--condensation reaction
--bond has partial double bond character - no rotation
--forms "polypeptides"
Polypeptide
protein -- chain of amino acids linked together with peptide bonds
Protein backbone
linear chain of bonds at the core of the polypeptide, consists of both NONrotating
peptide bonds and rotating, single intervening bonds
Amino acid specification
Each has a unique side chain, a name, a 3 letter code, and a one letter code
Where are charged amino acids usually located?
Outside of a protein; can also make ionic bonds with each other inside a protein
Amino Acids with polar but uncharged side chains
UPDATE.Buy Quality Materials!
Relationship of structure and function of macromolecules
Structure determines function
(ex. lysosyme - bacteria fit precisely into cleft)
ionic bond
attraction between opposite electrical charges at specific sites
--weak interaction
--non directional
hydrogen bond
bond formed when two chemical groups share a hydrogen
--O is more electronegative than H, pulls more strongly on electrons, giving O a partial
negative charge and H and partial positive charge
--directional!
Polar molecules
molecules with fully charged or partially charged atoms
--ionic and H bonds form between these types of molecules
hydrophobic interaction
nonpolar, uncharged atoms surfaces on macromolecules have no H bond
donors/acceptors and no charge to form ionic bonds; and so tend to aggregate together
at the interior of the molecule
van der Waals interaction
brief interactions that occur b/c of random variations in electron distribution in one
molecule creates a dipole, which causes opposite charge distribution in a nearby
molecule -- leads to a temporary partial charge attraction
Covalent bond
sharing of electron pairs; strongest interaction (by a LOT)
Strength of noncovalent interactions
Ionic ------------------------------- 3-7
H bond -----------------------------3-7
Hydrophobic interaction---------1-2
van der Waals interaction-------1
Ionic bond (photo)
HO
l ll
N -- H(+ -)O -- C--
l
H
Hydrogen bond (photo)
H
l (8+) (8-) l
-- N -- H ....... O = C --
Hydrophobic Interaction (photo)
, HHHH
ll\l
-- C -- C -- H C -- C
ll/ll
HHHHH
van der Waals forces (photo)
HH
... \ /
H--H :::::: C
.. / \
HH
characteristics/functions of the four noncovalent interactions
--individually too weak to allow binding
--working together, can be strong enough for binding, however still weak enough to be
reversible
--surface interactions allow macromolecules to reversibly bind substrates
Protein
macromolecule - long chain of amino acids, linked by covalent bonds -- "polypeptide"
--each type of protein uses a unique sequence of amino acids, each protein has unique
shape and function
amino acid
protein monomer
consists of:
--amino group (NH3+)
--carboxl group (COO-)
--H
--R side chain
all attached to the alpha carbon
R chain
20 types - determine type of amino acid
peptide bond
covalent bond between amino acids
(between carboxl and amine groups of two amino acids)
--condensation reaction
--bond has partial double bond character - no rotation
--forms "polypeptides"
Polypeptide
protein -- chain of amino acids linked together with peptide bonds
Protein backbone
linear chain of bonds at the core of the polypeptide, consists of both NONrotating
peptide bonds and rotating, single intervening bonds
Amino acid specification
Each has a unique side chain, a name, a 3 letter code, and a one letter code
Where are charged amino acids usually located?
Outside of a protein; can also make ionic bonds with each other inside a protein
Amino Acids with polar but uncharged side chains
