Cell Signaling Review Flashcards

These flashcards cover key concepts related to cell signaling as presented in the lecture notes.

What are the four requirements for cell signaling?

Signaling cell, signaling molecule, receptor protein, responding cell.

Give an example of a signaling cell in multicellular life.

Cells in adrenal glands.

What does the signaling molecule adrenaline do in the body?

It causes physiological changes such as increased heart or breathing rate.

What occurs at low cell density in bacterial cells?

The concentration of signaling peptide is too low to bind to receptors and stimulate DNA uptake.

At high cell density, why can bacterial cells take up DNA?

The concentration of signaling peptide is high enough to bind to receptors and stimulate DNA uptake.

What are the steps of cell signaling? List them.

Receptor activation, signal transduction, response, termination.

What is endocrine signaling?

Signaling where molecules travel through the circulatory system.

How do growth factors relate to paracrine signaling?

Growth factors are types of paracrine signaling molecules that promote cell growth.

What is autocrine signaling?

When the signaling cell and responding cell are the same.

What is an example of contact-dependent signaling?

Delta-Notch signaling in development.

What binds to receptor proteins during cell signaling?

Signaling molecules, also known as ligands.

Where are intracellular receptors located?

In the cytoplasm or nucleus of the cell.

What happens when ligands bind to cell-surface receptors?

The receptor undergoes a conformational change and becomes activated.

Name the three main groups of cell surface receptors.

G protein-coupled receptors, receptor kinases, ion channels.

What happens to a G protein-coupled receptor when a ligand binds?

The receptor becomes active and can bind to the G protein.

What is the role of cAMP in heart muscle stimulation?

cAMP transmits signals from G protein to inside the cell, activating protein kinase A.

How does adrenaline signal amplification occur?

Each adrenaline-bound receptor activates multiple G proteins, leading to a cascade of responses.

What is the role of phosphatases in signaling?

They degrade cAMP and remove phosphate groups from activated proteins.

What occurs when a receptor kinase binds to its ligand?

The receptor dimerizes and phosphorylates another protein.

What triggers the MAP kinase pathway?

GTP-bound Ras activates a kinase cascade leading to gene expression associated with cell division.

What is a ligand-gated ion channel?

An ion channel that alters the flow of ions across the membrane when a ligand binds.

How can cancer develop in relation to cell signaling?

Through overproduction of signaling molecules, mutations prolonging activation of Ras, or excess receptor binding.

What is the integration of signaling pathways?

The interaction of various pathways that may stimulate or inhibit responses within the cell.

What are the consequences of different signaling pathways in mammalian cells versus yeast cells?

In mammals, MAP kinase pathway promotes cell division; in yeast, it triggers sexual reproduction.