Lecture 1: Cell communication Flashcards
Understand the conceptual basis of cell communication ● Understand what a signal can be ● Understand how cells can respond to signalling ● Understand how a signal is regulated and why this is important.
Learning Objectives
● Conceptual basis of cell communication
● What a signal can be
● How cells can respond to signalling
● How a signal is regulated
● Why signal regulation is important
List the common types of signals
● Endocrine
●Paracrine
● Contact Dependent
● Synaptic
What are some details of the ‘Conceptual basis of communication’?
(what communication is used for, basic characteristics of a communication)
● Communication is needed for development and homeostasis
● Speed, Duration, Mechanism
Explain contact-dependent signalling
● Cells are in direct contact with each other
● Signal leaves signalling cell and is received by receptors on membrane of target cell
Explain synaptic signalling (nature, target cells and example)
Nature - Neurotransmitter transmitted across synapses
Target cells - e.g. neurons or muscles
example - communication between neurons in the nervous system
Explain paracrine signalling
● allows cells to communicate with each other by releasing signalling molecules/local mediator that bind to and activate surrounding cells.
● The cells which receive the signal are not always directly adjacent to the signalling cell
Explain endocrine signalling.
Provide an example, explain how it acts and what general response it has
● When hormones are released into the bloodstream by endocrine glands
● Adrenaline (mostly produced by adrenal glands) -> acts via adrenergic receptors - > produces physiological effects associated with fight or flight
Reading material on signalling.
What is the difference between a qualitative and a quantitative response to a signal?
● The strength or concentration of the signalling molecule determines the extent of a cell’s response
● Quantitative response to a signal
● Qualitatively different response to a signal
Quantitative - Involves measuring the strength or concentration of the signal and what outcome this has for the cell
Qualitative - Focus on the nature and diversity of cellular outcomes
What is a morphogen?
What happens in a morphogen gradient in relation to how cells respond to signalling?
Morphogen - A molecule that emanates from a specific set of cells that is present in a concentration gradient and that specifies the fate of each cell along this gradient
In a morphogen gradient, cellular responses occur at specific thresholds along the conc gradient
How can cells respond to a signal?
3 points. Mention the speeds.
● By changing the structure of an existing protein e.g. ion channel (very fast)
● By changing the post translational modifications e.g. phosphorylation (fast)
● Changing protein levels through gene expression (Slower)
