BIOL230W Week 7 Signaling Pathways

These flashcards cover key concepts, definitions, and functions related to signaling pathways discussed in the BIOL230W Week 7 lecture.

What are the major components of a signaling pathway?

Signals, receptors, second messengers, and final targets/effectors.

What is a signal in the context of cell signaling?

A chemical, also known as a ligand, that initiates the signaling process.

How do receptors function in cell signaling?

Receptors are integral proteins that sense signals and undergo conformational changes upon binding to ligands.

What happens to the receptor upon ligand binding?

The binding of the ligand causes conformational changes in the receptor, altering its function.

What role do second messengers play in signaling pathways?

Second messengers transduce signals within the cell after the primary signal has been received.

Give examples of second messengers mentioned in the notes.

cAMP, IP3, DAG, and calcium (Ca2+).

What is the effect of receptor tyrosine kinases (RTKs) when activated?

They undergo autophosphorylation, activating their tyrosine kinase domain, which phosphorylates other proteins.

What is the result of G-protein activation upon ligand binding?

The G-protein undergoes a conformational change that allows it to bind GTP and subsequently activate downstream effectors.

What is the final effector in a signaling pathway?

The last protein altered by the pathway, which can lead to physiological changes such as alterations in gene expression.

What occurs if a signaling pathway is blocked or altered?

It may prevent communication between cells, which can lead to changes in function or disease.

What does the term 'transduction' refer to in a signaling pathway?

The process of relaying the signal through the cell after it is received by the receptor.

What structural change do receptors undergo when they bind a ligand?

They undergo a conformational change that allows them to initiate signal transduction.

What types of signals can activate a signaling pathway?

Signals can be diverse, originating from environmental or cellular sources, such as proteins, hormones, and growth factors.

Describe the general characteristics of a signaling pathway.

Typically involves the use of receptors, second messengers, effectors, and results in specific cellular responses.

What happens to calcium ions during signaling involving IP3?

IP3 causes calcium release from the endoplasmic reticulum into the cytoplasm.

What can the activation of kinases lead to in a signaling pathway?

It can amplify the signal by phosphorylating multiple downstream effectors.

How do phosphatases interact with signaling pathways?

Phosphatases remove phosphate groups, opposing the action of kinases and regulating signaling pathways.