Lecture 1 - Cell Communication a introduction Flashcards
What is contact-dependent cell communication?
Contact-dependent cell communication is when a membrane-bound signal molecule attaches to a receptor on the target cell, resulting in a 1 to 1 cell communication.
What is synaptic cell communication?
Synaptic cell communication is a short-range communication where neurotransmitters (NTMs) travel across synapses between neurons to attach to target cells.
What is paracrine cell communication?
Paracrine cell communication produces a local mediator that can spread around a medium range.
What is endocrine communication ?
Endocrine cell communication is a locally acting, quick-action cell communication that releases a hormone that circulates through the body to impact a huge range of tissues and make systemic alterations.
How do cells respond to signalling?
Cells respond to signaling through intracellular signaling proteins that respond to the extracellular signal molecule. Effector proteins include metabolic enzyme (alters metabolism), gene regulatory protein (alters gene expression), and cytoskeletal protein (alters shape or movement).
What is the morphogen gradient?
The morphogen gradient is a special case where responses occur at specific thresholds.
How is signalling regulated ?
Signaling is regulated through two methods: positive feedback and negative feedback. Positive feedback response of A is being positively increased by making of B, while negative feedback occurs when the stimulus is stronger than B, and when the stimulus goes away, the presence of B turns A off.
What is the issue with fast responses in signalling ?
Fast responses require a rapid turnover of the effector, which is wasteful and uses a lot of ATP and energy.
How can the issue of fast responses in signaling be resolved?
The issue of fast responses in signaling can be resolved through post-translation modification, which keeps the protein but just has it active or inactive. Examples include GDP/GTP signaling and phosphorylation.
