How does an enzyme cascade contribute to the amplification feature of signal-transducing systems?

Correct answer: An enzyme associated with a receptor activates many molecules of a second enzyme, which in turn each activate many molecules of a third enzyme, leading to a geometric increase in affected molecules.

Explanation

Signal amplification via enzyme cascades is a key feature of signaling pathways, allowing a small initial signal to produce a large cellular response very quickly.

Other questions

Question 1

What is the primary factor that accounts for the specificity of signal transduction, ensuring a signal molecule fits its complementary receptor and other signals do not?

Question 3

What is the general structure of a G protein–coupled receptor (GPCR)?

Question 4

In the beta-adrenergic signaling pathway, what is the direct role of the activated Gs-alpha subunit?

Question 5

What event triggers the autophosphorylation of the insulin receptor (INSR)?

Question 6

In the insulin signaling pathway, what is the function of the PI3K enzyme after it is activated by binding to phosphorylated IRS-1?

Question 7

What is the role of nitric oxide (NO) in signaling pathways?

Question 8

Which type of protein domain specifically binds to phosphorylated tyrosine (P-Tyr) residues in partner proteins?

Question 9

What is the typical resting membrane potential (Vm) of an animal cell?

Question 10

What is the function of integrins in cellular signaling?

Question 11

How do steroid hormones typically regulate gene expression?

Question 12

In the visual transduction pathway, what is the immediate effect of light absorption by rhodopsin?

Question 13

What is the function of the G protein transducin in the rod cell signaling cascade?

Question 14

In the regulation of the eukaryotic cell cycle, what is the primary role of cyclin-dependent protein kinases (CDKs)?

Question 15

What is the function of the tumor suppressor protein pRb (retinoblastoma protein)?

Question 16

What is the effect of the drug tamoxifen in the treatment of some breast cancers?

Question 17

What is the typical dissociation constant (Kd) for a hormone-ligand interaction, corresponding to very tight binding?

Question 18

In olfactory neurons, what is the role of the G protein Golf?

Question 19

In the human genome, approximately how many genes encode G protein-coupled receptors (GPCRs)?

Question 20

What is apoptosis?