Examine cellular communication and signal transduction.

Question 1

Question 1: What are cellular receptors, and what is their main function?

A. Small molecules found in the cytoplasm that bind to ligands
B. Protein molecules that can recognize and bind with specific ligands
C. Lipid molecules that serve as messengers in the cell
D. Enzymes involved in cellular metabolism

Answer 1

B. Protein molecules that can recognize and bind with specific ligands

Question 2

Question 2: What is the binding site of a protein receptor?

A. The region of a protein that associates with a ligand
B. The internal structure of the nucleus
C. The location where cellular uptake of ligands occurs
D. The portion of the receptor exposed to the cytoplasm

Answer 2

A. The region of a protein that associates with a ligand

Question 3

Question 3: What type of interactions are involved in the formation of weak, noncovalent bonds between receptors and ligands?

A. Covalent bonds
B. Hydrogen bonds, electrostatic attractions, and Van der Waals attractions
C. Ionic bonds
D. Polar bonds

Answer 3

B. Hydrogen bonds, electrostatic attractions, and Van der Waals attractions

Question 4

Question 4: Where are plasma membrane receptors typically located?

A. In the cytoplasm
B. In the nucleus
C. Exposed at the external surface of the plasma membrane
D. Within the endoplasmic reticulum

Answer 4

C. Exposed at the external surface of the plasma membrane

Question 5

Question 5: What are some examples of ligands that bind with plasma membrane receptors?

A. Lipids and carbohydrates
B. Enzymes and nucleic acids
C. Hormones, neurotransmitters, and antigens
D. Ribosomes and organelles

Answer 5

C. Hormones, neurotransmitters, and antigens

Question 6

Question 6: How do membrane receptors for endorphins affect a cell when bound to a receptor?

A. They decrease the cell’s permeability to ions.
B. They initiate molecular events that enhance pain perception.
C. They increase the concentration of molecules that inhibit protein synthesis.
D. They change the cell’s permeability to ions and modulate pain perception.

Answer 6

D. They change the cell’s permeability to ions and modulate pain perception.

Question 7

Question 7: What is the primary function of antigen receptors on white blood cells?

A. To recognize and bind with endorphins
B. To initiate the immune and inflammatory responses
C. To activate the synthesis of lipoproteins
D. To transport ions across the plasma membrane

Answer 7

B. To initiate the immune and inflammatory responses

Question 8

Question 8: Which cellular component determines which ligands a cell will bind with and how it will respond to the binding?

A. Nucleus
B. Cytoplasm
C. Plasma membrane receptors
D. Mitochondria

Answer 8

C. Plasma membrane receptors

Question 9

Question 1: What are the four main reasons for cells to communicate with each other?

A. Growth, differentiation, development, and coordination
B. Homeostasis, growth, regulation, and coordination
C. Homeostasis, growth and division, development, and coordination
D. Maintenance, organization, regulation, and coordination

Answer 9

C. Homeostasis, growth and division, development, and coordination

Question 10

Question 2: Which of the following is NOT one of the primary modes of intercellular signaling?

A. Contact-dependent signaling
B. Paracrine signaling
C. Endocrine signaling
D. Cellular signaling

Answer 10

D. Cellular signaling

Question 11

Question 3: What type of signaling involves specialized endocrine cells that secrete hormones into the bloodstream?

A. Paracrine signaling
B. Autocrine signaling
C. Hormonal signaling
D. Neurohormonal signaling

Answer 11

C. Hormonal signaling

Question 12

Question 4: In which type of signaling do neurons release neurotransmitters at chemical synapses?

A. Hormonal signaling
B. Endocrine signaling
C. Paracrine signaling
D. Neurohormonal signaling

Answer 12

D. Neurohormonal signaling

Question 13

Question 5: What is the primary mechanism of communication in ion channel coupled plasma membrane receptors?

A. Activation of enzymes
B. Activation of G-proteins
C. Changes in ion permeability through channels
D. Activation of inositol phospholipids

Answer 13

C. Changes in ion permeability through channels

Question 14

Question 6: Which type of receptor indirectly activates or inactivates plasma membrane enzymes or ion channels through G-proteins?

A. Ion channel coupled receptors
B. Enzyme coupled receptors
C. G-protein coupled receptors
D. Inositol phospholipid coupled receptors

Answer 14

C. G-protein coupled receptors