quizzes 3 and 4 Flashcards
What is the Bohr effect in hemoglobin’s function?
A. It illustrates the pH-dependent binding of oxygen by hemoglobin.
B. It explains how hemoglobin transports carbon dioxide.
C. It describes the effect of temperature on hemoglobin function.
D. It refers to the impact of pressure on hemoglobin’s structure.
A. It illustrates the pH-dependent binding of oxygen by hemoglobin.
In the context of hemoglobin, what is the “T-state”?
A. The relaxed state of hemoglobin with higher oxygen affinity.
B. The constricted state of hemoglobin with lower oxygen affinity.
C. The state when hemoglobin is saturated with oxygen.
D. The state when hemoglobin releases oxygen to tissues.
B. The constricted state of hemoglobin with lower oxygen affinity.
Which statement accurately describes the role of myosin in muscle contraction?
a. Myosin acts as a stabilizing protein in muscle fibers.
b. Myosin regulates muscle relaxation.
c. Myosin binds directly to actin, causing muscle contraction.
d. Myosin hydrolyzes ATP to produce energy for muscle contraction.
d. Myosin hydrolyzes ATP to produce energy for muscle contraction.
Which molecules often serve as cofactors for enzymes, assisting in their catalytic functions?
a. Coenzymes and vitamins
b. Activation Energy
c. Muscle contraction
d. Enzymes: General properties
a. Coenzymes and vitamins
The energy required to initiate a chemical reaction is known as:
a. Activation Energy
b. Enzymes: General properties
c. Entropy
d. Specificity of binding
a. Activation Energy
Which concept refers to the regulation of enzyme activity by binding at a site other than the active site?
A. Competitive Regulation
B. Hemoglobin Function
C. Allosteric Regulation
D. Structure and Mechanism of Hemoglobin and Myoglobin
C. Allosteric Regulation
In allosteric regulation, what is the role of an allosteric effector?
A. It stabilizes the enzyme’s tertiary structure.
B. It affects the enzyme’s activity by binding at a remote site.
C. It competes with the substrate for the active site.
D. It binds to the enzyme’s active site.
B. It affects the enzyme’s activity by binding at a remote site.
Enzymes exhibit catalytic efficiency. What is meant by a high catalytic efficiency?
A. The enzyme can bind multiple substrates at once.
B. The enzyme can function at a wide range of pH values.
C. The enzyme can convert a large amount of substrate into product per unit of time.
D. The enzyme is resistant to denaturation.
C. The enzyme can convert a large amount of substrate into product per unit of time.
Which of the following statements accurately describes the cooperativity of hemoglobin?
A. Hemoglobin exhibits positive cooperativity, meaning it binds oxygen more tightly as more oxygen molecules are bound.
B. Hemoglobin exhibits negative cooperativity, meaning it binds oxygen more tightly after the first oxygen molecule is bound.
C. Hemoglobin’s cooperativity is solely dependent on pH.
D. Hemoglobin does not exhibit cooperativity; it binds oxygen independently of previous binding events.
A. Hemoglobin exhibits positive cooperativity, meaning it binds oxygen more tightly as more oxygen molecules are bound.
How does fetal hemoglobin (Hemoglobin F) differ from adult hemoglobin (Hemoglobin A)?
A. Hemoglobin F has a higher oxygen-binding affinity.
B. Hemoglobin F is found primarily in adults.
C. Hemoglobin F is more sensitive to pH changes.
D. Hemoglobin F contains a different metal ion at its core.
A. Hemoglobin F has a higher oxygen-binding affinity.
Which of the following factors can affect enzyme activity?
A. Substrate concentration
B. Inhibitors
C. All of the above
D. Temperature and pH
C. All of the above
The Km value in enzyme kinetics represents:
A. The substrate concentration at which the reaction rate is half of Vmax.
B. The pH at which the enzyme works optimally.
C. The maximum reaction rate of the enzyme.
D. The temperature at which the enzyme is most active.
A. The substrate concentration at which the reaction rate is half of Vmax.
Allosteric enzymes are regulated by:
A. Coenzymes
B. Competitive inhibitors
C. Substrate concentration
D. Modulators that bind to regulatory sites
D. Modulators that bind to regulatory sites
In general catalytic mechanisms, enzymes accelerate reactions by providing an alternative reaction pathway that:
A. Depends on coenzymes.
B. Requires a higher pH.
C. Decreases the activation energy.
D. Increases the activation energy.
C. Decreases the activation energy.
Acid-base catalysis involves the transfer of protons during a chemical reaction. Which of the following best describes an acid catalyst?
A. Accepts protons.
B. Donates protons.
C. Acts as a reducing agent.
D. Has no effect on proton transfer.
B. Donates protons.
