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Chapter 9 Cell Communication Dr. Joseph Silver. this chapter deals with how cells receive messages what changes take place in the cell and what changes take place in the nucleus. how one cell signals another is defined by the distance from the source to the receptor 5 types are described.
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this chapter deals withhow cells receive messageswhat changes take place in the celland what changes take place in the nucleus
how one cell signals another is defined by the distance from the source to the receptor5 types are described
the key to everything thatgoes on in a cell is phosphorylationordephosphorylation
start or stopinhibit or activateturn on or turn offall happen byadding or removing a phosphate functional group
receptors are definedby their location- on a membrane- in a membrane- trans membrane- cytoplasmic
there are three types ofmembrane receptors- channel receptors-enzyme receptors-G protein-coupled receptors
some receptors such as steroid hormone receptorsare not in the membranebecause the message can pass right throughthe membraneso activation takes place inthe cytoplasm
there are three very importantkinases in cellsRTK, RSK, RTyKthese kinases add or remove phosphatefrom molecules and influence most reactions taking place in every cell
see fig 9.6 to see- message to receptor linkage- autophosphorylation- activation of protein by phosphorylationthen
Go to fig 9.7 to see- activation of 2nd and 3rd messengers- activation of enzyme- result of work stimulated by enzyme activity
look at fig 9.8 to seeamplification of eventsanother word for multiplicationin some cases instead of a 1 to 1 relationshipthere isa 1 to 2, then 2 to 4, then 4 to 8 relationshipas more and more reactions or systems are amplified or inhibited
We have previously studiedhomeodomainsand multienzyme complexesnow they are giving in fig 9.9another name for a multienezyme complexa scaffold proteinwhich holds in placea number of kinase cascadesfor increased efficiency
Now look at fig 9.11 & 9.12to see the whole processfrom ligand binding to receptortoresponse by cell
At the end of the chapter they want you to understand thatthere are many kinds of 2nd and 3rd etc. messengers