Cell Signalling in Biology

Flashcards covering vocabulary and concepts related to chemical signalling in cells, including mechanisms and types of signalling molecules.

Cell Signalling

The process by which messages are sent to cells, allowing multicellular organisms to control and coordinate their bodies.

Ligands

Signalling molecules that are secreted from a sending cell into the extracellular space to bind to specific receptors on a target cell.

Quorum Sensing

A mechanism by which bacteria communicate to assess population size and alter gene expression accordingly.

Epinephrine

A hormone also known as adrenaline that increases blood glucose concentration in response to biological stress.

Transmembrane Receptors

Receptors located in the cell membrane that extend across the membrane and have both external binding sites and internal regions.

Intracellular Receptors

Receptors that bind ligands, such as steroid hormones, that can diffuse through the cell membrane and interact inside the cell.

Signal Transduction Pathway

The sequence of events that follow ligand binding to a receptor, resulting in a change in cell activity.

Hormones

Chemical substances produced by glands and carried by the blood that alter the activity of specific target organs.

Neurotransmitters

Chemicals that transmit signals across synapses from presynaptic to postsynaptic neurones.

Cytokines

Proteins released by cells that influence the activity of other cells, especially during immune responses.

Calcium ions (Ca2+)

Ions involved in various signaling pathways, acting as second messengers in some cases.

G-Protein Coupled Receptors (GPCRs)

A large family of receptors that activate G-proteins, initiating signal transduction pathways.

Receptor Tyrosine Kinase (RTK)

A class of transmembrane receptors that, when activated by a ligand, undergo phosphorylation and instigate signal transduction.

Negative Feedback

A mechanism that counteracts changes in physiological factors to maintain homeostatic balance.

Positive Feedback

A mechanism where the response to a stimulus amplifies the original stimulus, leading to a greater deviation from the norm.