COPY: Quiz 16

10 Questions

The first step in a signaling pathway that responds to a molecule that stays in the extracellular space is

binding of the signal molecule to a receptor.

What type of cell response would take the longest amount of time (on the scale of minutes to hours) to execute?

one that involves a change in gene expression

Which of the following is NOT an intracellular signaling protein activated by an RTK?

G-protein

Steroid hormones trigger transcription of target genes by

binding to nuclear receptors that act as transcription factors for specific genes.

Which of the following types of cell signaling is long range and uses hormones as signals?

endocrine

The active form of a monomeric GTP-binding protein is the

GTP-bound form.

Which of the following describes negative feedback regulation?

A component late in the pathway inhibits an enzyme early in the pathway.

Enzymes that add a phosphate group to a switch protein are called

kinases.

How does the binding of a signal molecule activate an RTK for downstream signaling?

The RTK forms a dimer and cross-phosphorylates itself.

Shown below is a diagram of how theoretical intracellular signaling pathways could integrate incoming signals to produce a coordinated cell response.

signals A and D

Study Notes

Signaling Pathways

The first step in a signaling pathway that responds to a molecule staying in the extracellular space involves a receptor protein on the cell surface.

Cell Response Time

The cell response that would take the longest amount of time (on the scale of minutes to hours) to execute is a transcriptional response, which involves changes in gene expression.

RTK Signaling

Notch receptor is NOT an intracellular signaling protein activated by an RTK (Receptor Tyrosine Kinase).
RTKs are activated when a signal molecule binds to the receptor, causing its auto-phosphorylation, which leads to the recruitment of downstream signaling proteins.

Hormone Signaling

Endocrine signaling is a type of long-range cell signaling that uses hormones as signals.

GTP-Binding Proteins

The active form of a monomeric GTP-binding protein is the GTP-bound form.

Negative Feedback Regulation

Negative feedback regulation occurs when the response to a signal reduces the strength or frequency of the original signal.

Signal Transduction

Enzymes that add a phosphate group to a switch protein are called protein kinases.
These kinases play a crucial role in signal transduction pathways, as they can activate or inhibit downstream proteins.