Biochem Chapter 5 Part 1

Where does a ligand typically bind on a protein, and is this binding usually reversible or irreversible?

• Active site; irreversible

• Binding site; reversible

• Allosteric site; irreversible

• Catalytic site; reversible

What structural changes occur in a protein when a ligand binds to it?

• The protein becomes denatured

• The protein's secondary structure is altered

• The protein undergoes a conformational change

• The protein's primary structure is altered

• Low affinity

• High affinity

• No affinity

• Moderate affinity

Which of the following are examples of hemeproteins?

• Myoglobin and hemoglobin

• Insulin and glucagon

• Collagen and elastin

• Actin and myosin

How many bonds can iron form in a heme group, and what does it typically bind to?

• 4 bonds; binds to oxygen

• 6 bonds; binds to nitrogen atoms in the heme

• 5 bonds; binds to carbon atoms in the heme

• 6 bonds; binds to sulfur atoms in the heme

Tags

NGSS.HS-LS1-6

How many polypeptides and hemes are found in myoglobin and hemoglobin, respectively?

• Myoglobin: 1 polypeptide, 1 heme; Hemoglobin: 4 polypeptides, 4 hemes

• Myoglobin: 2 polypeptides, 2 hemes; Hemoglobin: 2 polypeptides, 2 hemes

• Myoglobin: 1 polypeptide, 2 hemes; Hemoglobin: 4 polypeptides, 2 hemes

• Myoglobin: 4 polypeptides, 4 hemes; Hemoglobin: 1 polypeptide, 1 heme

What is the difference between the T and R states of hemoglobin, and which intermolecular force is most important for these states?

• T state is relaxed; R state is tense; hydrogen bonding is most important

• T state is tense; R state is relaxed; ionic interactions are most important

• T state is relaxed; R state is tense; van der Waals forces are most important

• T state is tense; R state is relaxed; hydrogen bonding is most important

Tags

NGSS.HS-PS1-2

What is the difference between deoxyhemoglobin and oxyhemoglobin, and which has a higher affinity for oxygen?

• Deoxyhemoglobin has no oxygen; oxyhemoglobin has oxygen; oxyhemoglobin has higher affinity

• Deoxyhemoglobin has oxygen; oxyhemoglobin has no oxygen; deoxyhemoglobin has higher affinity

• Both have oxygen; deoxyhemoglobin has higher affinity

• Both have no oxygen; oxyhemoglobin has higher affinity

What is cooperative binding in the context of hemoglobin?

• Binding of one oxygen molecule decreases the affinity for others

• Binding of one oxygen molecule increases the affinity for others

• Binding of one oxygen molecule has no effect on the affinity for others

• Binding of one oxygen molecule prevents the binding of others

• Decreases oxygen binding

• Increases oxygen binding

• Has no effect on oxygen binding

• Completely inhibits oxygen binding