Q: Which equation best represents the conversion of GTP to cGMP by guanylyl cyclase?

$$\mathrm{GTP} \xrightarrow{\text{guanylyl cyclase}} \mathrm{cGMP} + \mathrm{PP_i}$$

Question 1

Which of the following best describes the primary difference between electrical and chemical signals in cell-to-cell communication?

Accepted Answer

Electrical signals involve changes in a cell's membrane potential, while chemical signals are molecules secreted into extracellular fluid.

Question 2

Gap junctions allow for direct cytoplasmic connections between adjacent cells. Which type of molecules can pass through gap junctions?

Accepted Answer

Ions and small molecules such as ATP and amino acids

Question 3

Which statement about paracrine and autocrine signaling is correct?

Accepted Answer

Both paracrine and autocrine signals are chemical signals with a limited effective range due to diffusion.

Question 4

Which of the following is TRUE regarding hormones?

Accepted Answer

Hormones are chemical signal molecules secreted into the blood and only target cells with specific receptors respond.

Question 5

A neurocrine released in a synaptic cleft that rapidly affects a postsynaptic target cell is called:

Accepted Answer

Neurotransmitter

Question 6

Which of the following is a key difference between cytokines and hormones?

Accepted Answer

Cytokines act on a broader spectrum of target cells and are made on demand, while most hormones are made in advance and stored.

Question 7

Which of the following best describes the process of signal transduction?

Accepted Answer

Transmission of a signal from one side of the membrane to the other, often involving a cascade of activation steps and amplification.

Question 8

Which equation best represents the conversion of GTP to cGMP by guanylyl cyclase?

Accepted Answer

$$\mathrm{GTP} \xrightarrow{	ext{guanylyl cyclase}} \mathrm{cGMP} + \mathrm{PP_i}$$

Question 9

Which type of receptor is most likely to mediate rapid cellular responses by changing ion flow through channels?

Accepted Answer

Ligand-gated receptor channel

Question 10

A lipophilic signal molecule is most likely to bind to which type of receptor?

Accepted Answer

Receptors in the cytosol or nucleus, triggering slower responses related to gene activity.

Question 11

Which of the following is a function of integrin receptors?

Accepted Answer

Mediating blood clotting, wound repair, cell motility, and immune cell recognition.

Question 12

Which of the following is TRUE about G protein-coupled receptors (GPCRs)?

Accepted Answer

GPCRs are membrane-spanning proteins with a cytoplasmic tail linked to a G protein, and about half of all medications act through GPCRs.

Question 13

Which of the following best describes the role of amplifier enzymes in signal transduction?

Accepted Answer

They allow a small amount of signal to have a large effect by producing many second messenger molecules.

Question 14

A cell responds to a particular chemical signal only if it has a receptor for that signal. What is the term for the chemical signal that binds to the receptor?

Accepted Answer

Ligand

Question 15

Which of the following is a correct sequence for a signal transduction cascade?

Accepted Answer

Inactive A $$\rightarrow$$ Active A $$\rightarrow$$ Inactive B $$\rightarrow$$ Active B $$\rightarrow$$ Inactive C $$\rightarrow$$ Active C $$\rightarrow$$ Substrate $$\rightarrow$$ Product

Question 16

Which of the following is a plausible consequence of a mutation that prevents connexin protein formation in cardiac tissue?

Accepted Answer

Impaired gap junction formation, leading to disrupted electrical signal transmission and possible arrhythmias.

Question 17

Which of the following is most likely to occur if a cell lacks receptors for a specific hormone?

Accepted Answer

The cell will not respond to the hormone, regardless of its concentration in the blood.

Question 18

Which of the following is a real-world example of contact-dependent signaling?

Accepted Answer

Immune cells recognizing and binding to infected cells via cell adhesion molecules (CAMs).

Question 19

Which of the following best explains why paracrine signals have a restricted effective range?

Accepted Answer

The distance between cells limits diffusion, so paracrine signals only affect adjacent cells.

Cell Communication, Integration, and Homeostasis: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard