biology : class11 Receptor Tyrosine Kinases : Receptors, Second Messengers, Gene Regulation : Hormone Action MCQ Questions and Answers
Practice important
Receptor Tyrosine Kinases
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. What type of receptor is a receptor tyrosine kinase?
A.
A cell-surface receptor with enzyme activity
B.
A receptor found only inside the nucleus
C.
A receptor that directly transports ions
D.
A receptor made only of carbohydrates
Correct Answer:
A cell-surface receptor with enzyme activity
Explanation:
Receptor tyrosine kinases are cell-surface receptors whose intracellular part has enzyme activity that adds phosphate groups to tyrosine residues.
2. What usually happens when a signaling molecule binds to a receptor tyrosine kinase?
A.
The receptor changes shape and becomes activated
B.
The receptor is immediately destroyed
C.
The receptor moves into the nucleus unchanged
D.
The receptor stops interacting with the cell membrane
Correct Answer:
The receptor changes shape and becomes activated
Explanation:
Binding of a signaling molecule causes a conformational change that activates the receptor tyrosine kinase.
3. What is a common feature of receptor tyrosine kinase activation?
A.
Dimerization of two receptor molecules
B.
Splitting of the cell membrane
C.
Removal of all membrane proteins
D.
Conversion of DNA into RNA outside the nucleus
Correct Answer:
Dimerization of two receptor molecules
Explanation:
Many receptor tyrosine kinases become active when ligand binding brings two receptor molecules together to form a dimer.
4. Which enzyme activity is associated with the intracellular part of a receptor tyrosine kinase?
A.
Tyrosine kinase activity
B.
DNA helicase activity
C.
Peptidase activity only
D.
RNA polymerase activity
Correct Answer:
Tyrosine kinase activity
Explanation:
The intracellular domain of a receptor tyrosine kinase transfers phosphate groups from ATP to tyrosine residues.
5. Which molecule commonly provides the phosphate group used by a receptor tyrosine kinase?
A.
ATP
B.
Oxygen
C.
Glucose
D.
DNA
Correct Answer:
ATP
Explanation:
Receptor tyrosine kinases use ATP as the phosphate donor during phosphorylation of tyrosine residues.
6. What is the result of autophosphorylation in a receptor tyrosine kinase?
A.
Phosphate groups are added to tyrosine residues on the receptor
B.
The receptor loses its transmembrane region
C.
The receptor changes into a steroid hormone
D.
The receptor releases DNA into the cytoplasm
Correct Answer:
Phosphate groups are added to tyrosine residues on the receptor
Explanation:
Autophosphorylation activates the receptor by adding phosphate groups to tyrosine residues on its intracellular portion.
7. Why are phosphorylated tyrosine residues important in receptor tyrosine kinase signaling?
A.
They provide docking sites for signaling proteins
B.
They form the cell wall
C.
They digest the signaling molecule outside the cell
D.
They stop all enzyme activity in the cell
Correct Answer:
They provide docking sites for signaling proteins
Explanation:
Phosphorylated tyrosine residues can be recognized by other signaling proteins, helping transmit the signal inside the cell.
8. Where is the ligand-binding part of a receptor tyrosine kinase located?
A.
Outside the cell
B.
Inside the nucleus
C.
Inside the mitochondrion
D.
Within the DNA molecule
Correct Answer:
Outside the cell
Explanation:
The extracellular part of a receptor tyrosine kinase binds the signaling molecule, while the intracellular part carries out kinase activity.
9. Which type of signaling molecule commonly activates receptor tyrosine kinases?
A.
Growth factor
B.
Cellulose fiber
C.
Ribosomal RNA
D.
Bile salt only
Correct Answer:
Growth factor
Explanation:
Many growth factors bind to receptor tyrosine kinases and activate signaling pathways that influence cell growth and division.
10. What is the main role of a receptor tyrosine kinase in cell signaling?
A.
To transmit an external signal into the cell
B.
To store genetic information permanently
C.
To produce oxygen during photosynthesis
D.
To digest food in the intestine
Correct Answer:
To transmit an external signal into the cell
Explanation:
A receptor tyrosine kinase detects a signal outside the cell and activates intracellular phosphorylation events to pass the message inward.
Short Questions and Answers
Practice short questions and answers related to
Receptor Tyrosine Kinases
.
Short questions are currently unavailable for this page.