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WGU Biochemistry Final Exam Questions with 100% Correct Answers
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WGU Biochemistry Final Exam Questions with 100% Correct Answers
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WGU Biochemistry Final ExamQuestions with 100% Correct Answers
Hemoglobin's ability to bind or release oxygen depends on the pH of
the environment. This behavior is known as the Bohr effect.
Considering this, which of the following statements is true?
a. Hemoglobin binds to the oxygen at high pH and releases oxygen at
low pH. - ✔ ✔ pH is a measure of H+ ion concentration. High pH
indicates a more basic environment in which the H+ ion concentration
is low, as seen in the lungs. Under these conditions, hemoglobin binds
more oxygen. Low pH indicates an acidic environment in which the H+
ion concentration is high. Such conditions encourage the binding of H+
ions to hemoglobin and stabilizing a form of hemoglobin which
decreases the affinity for oxygen, resulting in release of oxygen.
Hemoglobin acts as a buffer and controls the pH of the blood by
binding to __________.
d. H+ ions. - ✔ ✔ H+ ions contribute to the acidity of blood. By binding
to these ions, hemoglobin is able to act as a buffer and maintain the pH
at an appropriate range.
,In the lungs, the CO2 concentration is [low] and the pH is [high], while
in the tissues, the CO2 concentration is [high] and the pH is [low]. - ✔
✔ In the lungs, CO2 concentration are low, resulting in decreased
carbonic acid and higher pH. This creates a more basic (or alkaline)
environment that promotes oxygen binding.In the tissues, CO2
concentration tends to be high, resulting in increased carbonic acid
which lowers the pH. This creates an acidic environment that
promotes oxygen release.
In locations where the pH is low, hemoglobin will be in the [T] state,
allowing it to [release] oxygen more effectively. - ✔ ✔ At low pH,
hemoglobin will be in the T, or tense, state to allow it to release
oxygen more effectively to oxygen-starved tissues.
Increased levels of 2,3-BPG will [decrease] the affinity for oxygen by
binding to and stabilizing the [T] state of hemoglobin. The action of 2,3-
BPG allows hemoglobin to [release] oxygen more effectively, which is
similar to the effect of [low] pH on the action of hemoglobin. -
✔ ✔ Increased levels of 2,3-BPG will Incorrect the affinity for oxygen by
binding to and stabilizing the Correct state of hemoglobin. The action of
2,3-BPG allows hemoglobin to Incorrect oxygen more effectively, which
is similar to the effect of Correct pH on the action of hemoglobin.
In comparison to adult hemoglobin, fetal hemoglobin has a [higher]
affinity for oxygen because it [doesn't bind] 2,3-BPG well. - ✔ ✔ Fetal
hemoglobin has a higher affinity for oxygen than adult hemoglobin
because its structure does not bind 2,3-BPG well. As a result, the T state
,of fetal hemoglobin is not stabilized and it remains more readily in
the R state, ready to bind oxygen even at lower concentrations.
Structurally, hemoglobin can bind ___ molecules of oxygen, all of
which could potentially be replaced by carbon monoxide.
b. 4 - ✔ ✔ Hemoglobin has four subunits, all of which contain heme
prosthetic groups. Each heme can bind an iron atom, and each iron
atom can bind an oxygen molecule resulting in the binding of a total
of four oxygen molecules. All four oxygen molecules can be potentially
replaced by carbon monoxide.
Carbon monoxide outcompetes oxygen for attachment to the
__________ group of hemoglobin where it is permanently, covalently
attached.
d. heme - ✔ ✔ Carbon monoxide has a higher binding affinity than
oxygen to the heme group of hemoglobin. Such binding is irreversible.
As carbon monoxide binds to hemoglobin, the protein subunits
change conformation to allow carbon monoxide to bind faster. This
process is called __________.
d. positive cooperativity - ✔ ✔ Carbon monoxide does competitively
inhibit the overall function of the hemoglobin protein.
, Note that the question is referring to how the binding of one carbon
monoxide molecule influences the conformation of the other subunits
and increases the overall binding affinity for the hemoglobin molecule.
Such a cooperative behavior exhibited by the subunits is referred to as
positive cooperativity.
Carbon monoxide shifts the Oxygen-Hemoglobin Dissociation Curve to
the left, while carbon dioxide shifts this curve to the right. Based on
your knowledge of the Bohr Effect, which of the following statements
is true?
b. Carbon dioxide decreases hemoglobin's affinity for oxygen, while
carbon monoxide increases it - ✔ ✔ Carbon dioxide, released by the
respiring cells, combines with the water molecules of plasma to form
carbonic acid. Carbonic acid increases the H+ ion concentration (low or
acidic pH). H+ ions stabilize the deoxy-conformation (T state) of
hemoglobin and allow oxygen release and delivery to the tissues. On
the other hand, carbon monoxide, which has a very high affinity for
hemoglobin than oxygen, binds and maintains hemoglobin in oxy-
conformation (R state). Oxy-conformation of HB is amenable to
further binding of carbon monoxide and shifts the Oxygen-
Hemoglobin Dissociation Curve to the left.
Glucose is a monosaccharide. It can be used as the raw material to
build which one of the following molecules?
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