Chapter 16 — Cell Signaling

Flashcards covering key concepts from Chapter 16 on Cell Signaling.

Cells communicate through __ signaling molecules such as hormones, neurotransmitters, and local mediators.

extracellular

To respond to a signal, a cell must have a __ that binds the signaling molecule.

matching receptor protein

The three main classes of cell-surface receptors are __, GPCRs, and enzyme-coupled receptors.

ion-channel-coupled receptors

GPCRs and enzyme-coupled receptors activate intracellular signaling __ that relay, amplify, and distribute the signal.

cascades

G proteins act as molecular __, toggling between active (GTP-bound) and inactive (GDP-bound) forms.

switches

Activation of adenylyl cyclase increases __, while phospholipase C produces IP■ and DAG.

cyclic AMP (cAMP)

Protein kinases like PKA, PKC, and CaM-kinases __ target proteins, altering their activity.

phosphorylate

Receptor tyrosine kinases (RTKs) are enzyme-coupled receptors that __ themselves and recruit signaling proteins.

phosphorylate

Mutations in Ras can lock it in the active state, driving uncontrolled cell __ and contributing to cancer.

division

PI 3-kinase–Akt signaling promotes cell survival and __, while Notch signaling regulates gene transcription.

growth

Steroid hormones and nitric oxide (NO) __ through membranes to bind intracellular receptors.

diffuse

Small intracellular molecules like cyclic AMP (cAMP), IP3, and Ca2+ that relay and amplify signals are known as __.

second messengers

Signal termination mechanisms, such as receptor downregulation and the action of __ phosphatases, ensure that cell responses are transient and reversible.

protein

In __ signaling, cells communicate by direct physical contact between their cell-surface bound signaling molecules.

contact-dependent

GPCRs and enzyme-coupled receptors activate intracellular signaling __ that relay, amplify, and distribute the signal.

cascades

G proteins act as molecular __, toggling between active (GTP-bound) and inactive (GDP-bound) forms.

switches

Activation of adenylyl cyclase increases __, while phospholipase C produces IP3 and DAG.

cyclic AMP (cAMP)

Protein kinases like PKA, PKC, and CaM-kinases __ target proteins, altering their activity.

phosphorylate

Receptor tyrosine kinases (RTKs) are enzyme-coupled receptors that __ themselves and recruit signaling proteins.

phosphorylate

Mutations in Ras can lock it in the active state, driving uncontrolled cell __ and contributing to cancer.

division

PI 3-kinase

–Akt signaling promotes cell survival and __, while Notch signaling regulates gene transcription.

growth

Steroid hormones and nitric oxide (NO) __ through membranes to bind intracellular receptors.

diffuse

Small intracellular molecules like cyclic AMP (cAMP), IP3, and Ca2+ that relay and amplify signals are known as __.

second messengers

Signal termination mechanisms, such as receptor downregulation and the action of ****__ phosphatases, ensure that cell responses are transient and reversible.

protein

In ****__ signaling, cells communicate by direct physical contact between their cell-surface bound signaling molecules.

contact-dependent

In __ signaling, cells communicate over long distances using hormones transported through the bloodstream.

endocrine

*__ signaling involves local mediators that act on nearby cells.

Paracrine

__ signaling delivers signals specifically and quickly to target cells through neurotransmitters at synapses.

Synaptic

Ion-channel-coupled receptors convert chemical signals into __ signals by opening or closing ion channels.

electrical

G-protein coupled receptors indirectly activate or inactivate plasma membrane-bound target proteins by means of __.

G proteins