Baylor CHE 4142 - Lahousse Exam 2
2026 Questions and Answers
Function of protein - Correct answer-Transport, Storage, Signaling
Ligand - Definition - Correct answer-molecules bound to the protein but are not
chemically modified
characteristics of ligands - Correct answer-regulators of protein function, antigens
and important substance that need to be transported or stored
catalysis - substrates - Correct answer-the molecules bound to the protein are
chemically modified but the protein is not
characteristics of substrates - Correct answer-precursors and fuel
rate constant of association (ka) - Correct answer-P + L --> PL
rate constant of disassociation (kd) - Correct answer-PL --> P+L
Ka - Correct answer-association constant
Kd - Correct answer-disassociation constant
kd/ka - Correct answer-(P)(L)/(PL)
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,Equation describing hyperbola: x=y/(y+z) - Correct answer-Y= (L)/Kd+(L)
fraction of binding sites occupied - Correct answer-Y=(sites occupied)/(total
available sites)
Y= (PL)/(PL)+(P)
strong binding (Kd) - Correct answer-Kd less than 10 nM
weak binding (Kd) - Correct answer-Kd greater than 10 nM
Function of Globins - Correct answer-oxygen transport, storage of oxygen, require
prosthetic group to bind oxygen (Heme), and prevents oxidation of Iron to Fe^3+
Characteristics of Heme - Correct answer-complex organic ring, iron is
hexahedrally coordinated by heme and two AA residues.
Myoglobin Prosthetic Group - Correct answer-heme
myoglobin structure - Correct answer-single PPT chain, folding into 8 a-helixes,
globular
function of myoglobin - Correct answer-storage and diffusion of oxygen with in
the cell, can bind CO, NO, H2S
What does P50 represent - Correct answer-the partial pressure of oxygen at which
1/2 the binding sites are occupied by the ligand (O2)
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, p50 of myoglobin - Correct answer-measure of ligand affinity, 1.95 torr or .26 kPa
structure of hemoglobin - Correct answer-tetramer of two subunits (a2b2),
globular,
4 ppt chain, 8 a-helixes except D in aHg. interaction between a1b2
prosthetic groups of hemoglobin - Correct answer-4 heme
function of hemoglobin - Correct answer-transport of oxygen
states of hemoglobin - Correct answer-T-state: low affinity,
R-state: high affinity
changing oxygen affinity - Correct answer-protein with multiple binding sites
cooperativity of hemoglobin - Correct answer-multiple binding sites that must be
able to interact with each other.
= positive homotropic regulation
positive cooperativity - Correct answer-first binding event increases affinity at
remaining sites, recognized by sigmoidal binding curves
negative cooperativity - Correct answer-first binding event reduces affinity at
remaining sites.
hemoglobin states and conformational changes - Correct answer-1. Hb in T-state
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2026 Questions and Answers
Function of protein - Correct answer-Transport, Storage, Signaling
Ligand - Definition - Correct answer-molecules bound to the protein but are not
chemically modified
characteristics of ligands - Correct answer-regulators of protein function, antigens
and important substance that need to be transported or stored
catalysis - substrates - Correct answer-the molecules bound to the protein are
chemically modified but the protein is not
characteristics of substrates - Correct answer-precursors and fuel
rate constant of association (ka) - Correct answer-P + L --> PL
rate constant of disassociation (kd) - Correct answer-PL --> P+L
Ka - Correct answer-association constant
Kd - Correct answer-disassociation constant
kd/ka - Correct answer-(P)(L)/(PL)
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,Equation describing hyperbola: x=y/(y+z) - Correct answer-Y= (L)/Kd+(L)
fraction of binding sites occupied - Correct answer-Y=(sites occupied)/(total
available sites)
Y= (PL)/(PL)+(P)
strong binding (Kd) - Correct answer-Kd less than 10 nM
weak binding (Kd) - Correct answer-Kd greater than 10 nM
Function of Globins - Correct answer-oxygen transport, storage of oxygen, require
prosthetic group to bind oxygen (Heme), and prevents oxidation of Iron to Fe^3+
Characteristics of Heme - Correct answer-complex organic ring, iron is
hexahedrally coordinated by heme and two AA residues.
Myoglobin Prosthetic Group - Correct answer-heme
myoglobin structure - Correct answer-single PPT chain, folding into 8 a-helixes,
globular
function of myoglobin - Correct answer-storage and diffusion of oxygen with in
the cell, can bind CO, NO, H2S
What does P50 represent - Correct answer-the partial pressure of oxygen at which
1/2 the binding sites are occupied by the ligand (O2)
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, p50 of myoglobin - Correct answer-measure of ligand affinity, 1.95 torr or .26 kPa
structure of hemoglobin - Correct answer-tetramer of two subunits (a2b2),
globular,
4 ppt chain, 8 a-helixes except D in aHg. interaction between a1b2
prosthetic groups of hemoglobin - Correct answer-4 heme
function of hemoglobin - Correct answer-transport of oxygen
states of hemoglobin - Correct answer-T-state: low affinity,
R-state: high affinity
changing oxygen affinity - Correct answer-protein with multiple binding sites
cooperativity of hemoglobin - Correct answer-multiple binding sites that must be
able to interact with each other.
= positive homotropic regulation
positive cooperativity - Correct answer-first binding event increases affinity at
remaining sites, recognized by sigmoidal binding curves
negative cooperativity - Correct answer-first binding event reduces affinity at
remaining sites.
hemoglobin states and conformational changes - Correct answer-1. Hb in T-state
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