Cell Communication Flashcards
What is cell communication ?
Cell communication is the process of cells detecting and responding to signals in the extra cellular environment.
What are the three parts of cell signaling?
- receive signal
- interpret signal
- respond signal
What happens during cell -to -cell communication?
There are many parts to cell to cell communication like:
Direct intercellular signaling: inside of one cell to into another cell
Contact-dependent signaling: signal has to touch the target cell
Autocrine: signaling itself
Paracrine: has no receptor for signaling
Endocrine: long distances 9hormonal -travel through bloodstream)
What are the three stages of cell signaling?
Receptor activation -> signal transduction -> cellular response
What happens during receptor activation ?
- Ligand -signaling molecule binds to receptor with a high degree of specificity
- ligands cause conformational change (change in shape)
What are enzyme linked receptors?
*enzyme linked - extra cellular domain binds, causes intracellular domain to become functional catalyst/enzyme
- protein kinases (most of them) : family of proteins, 250 aa sequences, every cell has 100s, eukaryotes have 1000 different
WHEN THE LIGAN BINDS it is the start of a phosphorylation (add phosphate) cascade, work in chains, results in the number of switches for a particular pathway
What are G protein coupled receptors?
- they contain transmembrane proteins
- activated receptors binds to G protein
- G protein to dissociate from receptors
- a subunit and b and y dimer interact with other proteins
What are ligand gated receptors?
- ligand binding causes ion channels to open and ions to flow through membrane
What are intracellular receptors?
- passes through membrane and binds to receptor in nucleus
- dimer of estrogen-receptor complexes binds to DNA
What are second messengers?
- they relay signals inside of the cell (ex: cAMP and Ca 2+)
- one effect of cAMP is to activate protein kinase A
- Activated PKA phosphorylates specific cellular proteins (enzyme transcription factors)
- no signaling molecules = effects of PKA reversed
