Lecture 7 Flashcards
chemical released by cell or gland which changes the behavior or metabolism of other cells locally or at a distance; different types whose structural differences dictate physical and functional differences
hormones
having a multi-ring organic structure which imparts the characteristic of water insolubility on these material; synthesized from cholesterol
steroid hormones
water soluble protein hormones like insulin, glucagon, PTH
polypeptide hormones
protein whose structure gives it the capability to bind specifically to a specific ligand such as a hormone
receptor
class of intracellular proteins responsible for recognizing and binding to steroid hormones and thyroxine; contain nuclear import signals and receptor/hormone complexes that regulate expression, genomic actions, by binding to specific transcriptional sites within genes in the nucleus. several G-protein coupled receptors and ion channels act non-genomically as cell surface receptors for certain steroid hormones
nuclear receptor
some polypeptide hormones are water soluble and can’t pass freely through membrane, so these signal the event of hormone binding on their extracellular surface through the region exposed intracellularly
cell surface receptors
duplicated short 6-10 bp DNA sequence in promoter region of a hormone response gene which directly binds the nuclear receptor and hormone complex
hormone response element
molecules that relay signals from receptors on the cell surface to target molecules inside the cell, in cytoplasm or nucleus; 3 types: hydrophilic, hydrophobic, and gases
second messenger
system of communication by which cells sense and respond to signals which generally originate extracellularly
intracellular cell signaling
cells responding to signals released at a distance and traveling via the bloodstream
endocrine signals
cells responding to signals released within the local environment
paracrine signals
cells responding to a signal to which was released by a similar cell in its local vicinity
autocrine signals
intercellular communication transmitted by oligosaccharide, lipid, or proteins in a cell membrane affecting either the emitting cell or adjacent cells. Requires physical contact between the 2 cells involved
juxtacrine signaling
synthesis and/or release of many hormones are regulated by
feedback loops
cell-cell communication is defined by
where the signal originates, where the signal is released into, where the target is/are located, what types of cells are involved in the signaling
