BCHM 307 CHAPTER 5 TEST
PREPARATION QUESTIONS WITH
CORRECT ANSWERS
Which allosteric effector has the greatest ability to stabilize the deoxy state of
hemoglobin? - Answer- BPG
what type of proteins are myoglobin and hemoglobin? - Answer- oxygen-binding
what is heme? - Answer- a protein prosthetic group that binds O2 (in myoglobin and
hemoglobin) or undergoes redox reactions (in cytochromes)
what is a prosthetic protein group? - Answer- an organic group (such as a coenzyme)
that is permanently associated with a protein
what is the amount of O2 bound to myoglobin a function of? - Answer- the oxygen
concentration and the affinity of myoglobin for O2
certain tertiary structures can accommodate for what? - Answer- a variety of amino acid
sequences; that is proteins with unrelated sequences adopt similar structures
how can one deduce considerable information about elements of protein structure that
are central to protein function - Answer- by looking at the similarities and differences in
sequences among evolutionarily related proteins like the globins
what corresponds to the time since the genes diverged? - Answer- the number of
sequence differences
what shape is the binding curve of myoglobin? - Answer- exponential
what shape is the binding curve of hemoglobin? - Answer- sigmoidal
what is cooperative binding? - Answer- a situation in which the binding of a ligand at
one site on a macromolecule affects the affinity of other sites for the same ligand; can
also be called an allosteric protein
how many heme groups does hemoglobin have? - Answer- 4
what are the keys to hemoglobin's physiological function? - Answer- its cooperative
binding behavior and low oxygen affinity
, what is an allosteric protein? - Answer- a protein in which the binding of ligand at one
site affects the binding of other ligands at other sites
what is a ligand - Answer- 1) a small molecule that binds to a larger molecule. 2) a
molecule or ion bound to a metal ion
what does the presence of BPG do? - Answer- it stabilizes the deoxy conformation of
hemoglobin, resulting in a lower affinity for O2 in hemoglobin
What is the cytoskeleton? - Answer- the network of intracellular fibers that gives a cell
its shape and structural integrity
what are the three types of cytoskeletal proteins? - Answer- actin filaments,
intermediate filaments, and microtubules
What is the actin polymer - Answer- a double chain of subunits in which each subunit
contacts four neighboring subunits
what is actin polymerization driven by? - Answer- the hydrolysis of ATP because it has a
very large -delta G value
what does actin polymerization do? - Answer- extends its "leading" edge
what does actin depolymerization do? - Answer- helps to retract its "trailing" edge
unlike actin, what does tubulin bind to? - Answer- a guanine nucleotide either GTP or
GDP
what is keratin? - Answer- an intermediate filament
what are intermediates? - Answer- exclusively structural proteins
what is the basic structural unit of an intermediate filament - Answer- dimer of alpha-
helices that wind around each other; a coiled cell
what is the most stable conformation for a polypeptide sequence containing repeating
units of Gly-Pro-Hyp? - Answer- a narrow left-hand helix
what type of helix is collagen? - Answer- triple
what amino acid occurs in the center of a collagen helix - Answer- glycine
how is the collagen triple helix stabilized - Answer- hydrogen bonding
PREPARATION QUESTIONS WITH
CORRECT ANSWERS
Which allosteric effector has the greatest ability to stabilize the deoxy state of
hemoglobin? - Answer- BPG
what type of proteins are myoglobin and hemoglobin? - Answer- oxygen-binding
what is heme? - Answer- a protein prosthetic group that binds O2 (in myoglobin and
hemoglobin) or undergoes redox reactions (in cytochromes)
what is a prosthetic protein group? - Answer- an organic group (such as a coenzyme)
that is permanently associated with a protein
what is the amount of O2 bound to myoglobin a function of? - Answer- the oxygen
concentration and the affinity of myoglobin for O2
certain tertiary structures can accommodate for what? - Answer- a variety of amino acid
sequences; that is proteins with unrelated sequences adopt similar structures
how can one deduce considerable information about elements of protein structure that
are central to protein function - Answer- by looking at the similarities and differences in
sequences among evolutionarily related proteins like the globins
what corresponds to the time since the genes diverged? - Answer- the number of
sequence differences
what shape is the binding curve of myoglobin? - Answer- exponential
what shape is the binding curve of hemoglobin? - Answer- sigmoidal
what is cooperative binding? - Answer- a situation in which the binding of a ligand at
one site on a macromolecule affects the affinity of other sites for the same ligand; can
also be called an allosteric protein
how many heme groups does hemoglobin have? - Answer- 4
what are the keys to hemoglobin's physiological function? - Answer- its cooperative
binding behavior and low oxygen affinity
, what is an allosteric protein? - Answer- a protein in which the binding of ligand at one
site affects the binding of other ligands at other sites
what is a ligand - Answer- 1) a small molecule that binds to a larger molecule. 2) a
molecule or ion bound to a metal ion
what does the presence of BPG do? - Answer- it stabilizes the deoxy conformation of
hemoglobin, resulting in a lower affinity for O2 in hemoglobin
What is the cytoskeleton? - Answer- the network of intracellular fibers that gives a cell
its shape and structural integrity
what are the three types of cytoskeletal proteins? - Answer- actin filaments,
intermediate filaments, and microtubules
What is the actin polymer - Answer- a double chain of subunits in which each subunit
contacts four neighboring subunits
what is actin polymerization driven by? - Answer- the hydrolysis of ATP because it has a
very large -delta G value
what does actin polymerization do? - Answer- extends its "leading" edge
what does actin depolymerization do? - Answer- helps to retract its "trailing" edge
unlike actin, what does tubulin bind to? - Answer- a guanine nucleotide either GTP or
GDP
what is keratin? - Answer- an intermediate filament
what are intermediates? - Answer- exclusively structural proteins
what is the basic structural unit of an intermediate filament - Answer- dimer of alpha-
helices that wind around each other; a coiled cell
what is the most stable conformation for a polypeptide sequence containing repeating
units of Gly-Pro-Hyp? - Answer- a narrow left-hand helix
what type of helix is collagen? - Answer- triple
what amino acid occurs in the center of a collagen helix - Answer- glycine
how is the collagen triple helix stabilized - Answer- hydrogen bonding
