Biosignaling Flashcards
(43 cards)
3 types of chemical biologicals signals that our cells use to respond to tehir surroundings, communicate with other cells, and alter their own internal environments
Hormones, cytokines, and neurotransmitters
Hormones can be
Peptide-
Steroid-
Amino acid-derived molecules
These are small proteins that modulate our immune system
Cytokines
Chemicals that transmit information between neurons
Neurotransmitters
Biochemical classes that biological signals can belong to
Lipids, amino acids, proteins, and gases (nitric oxide for neurotransmitters)
Signals that act within the cell that synthesizes them
Intracrine signals
Signals are released, then bind to receptors on the cell that synthesizes them. But they first get out of the cell that synthesized them and then bind to its receptors
Autocrine signals
These target cells that are directly attached to the signaling cell
Juxtacrine signals
These target cells that in the general vicinity of the cell that emits the signal
Paracrine signals
Signals (hormones) travel between distant cells through circulatory system
Endocrine signals
Inflammation involves the release of ________, which generally affect nearby cells via _________ signaling
Cytokines ; paracrine
Neurotransmitters are what kind of signaling molecules
Paracrine
When the signaling molecule binds to a receptor, the signaling molecule is called what
Ligand
The ligand that binds to the receptor in the cell membrane is called the _______ _________ since it initiates the signaling pathway
First messenger
If the receptor triggers another biosignal inside the cell, the internal signaling molecule is called what?
Second messenger
Common second messengers
Calcium ions and cAMP
Receptors can be divided into 2 categories
Membrane receptors and nuclear receptors
These receptors are attached to the plasma membrane and often contain tab least one transmembrane domain, so it can relay message from outside of the cell to the interior of the cell
Membrane receptors
A protein domain which passes through the cell membrane; mostly made of hydrophobic amino acids
Transmembrane domain
Ligands that bind to membrane receptors are typically?
Polar (charged or have a lot of polar functional groups)
These receptors bind to non polar or lipid-based ligands, such as steroid and thyroid hormones which can diffuse directly through the cell membrane
Nuclear receptors
Are receptors found either in the nucleus or cytoplasm, and when the ligand binds the ligand-receptor complex migrates to the nucleus if it’s not already there
Free-floating Nuclear receptors
When bound to their ligands, nuclear receptors essentially function as what?
Transcription factors- they regulate the rate of gene transcription (turn it up or down)
3 types of membrane receptors
- Ion channel-linked
- Enzyme-linked (Catalytic)
- G protein-coupled (GPCR)