BIO 360 - Exam 1 - Chapter 6 Signaling SP 2023 PowerPoint Flashcards
What is the Nernst Equation?
How do cells talk to each other?
- electrical communication via gap junctions – direct
cytoplasmic links between cells. - chemical communication via neurotransmitters,
hormones, paracrine factors, contact-dependent
molecules.
Major basis for classification is ______ over which
signal is transmitted.
distance
Physiological signals
* ______ ______
Changes in the membrane potential of a cell
* ______ ______
Secreted by cells into extracellular fluid (ECF)
Responsible for most communication within the body
Chemical signals are ______.
* Target cells, or targets, respond to signals
Electrical signals / Chemical signals / ligands
What is the role of gap junctions with direct contact and local cell-to-cell communication?
- Gap junctions transfer both chemical and electrical signals.
- They form direct cytoplasmic connections between adjacent cells.
Local communication - Gap junctions create cytoplasmic bridges
- Contact-dependent signals require cell-to-cell contacts,
- Cell Adhesion Molecules transfer signals in both directions
Methods of cell-to cell communication
Local communication uses ______ and ______ signals.
Autocrine – same cell
Paracrine – different cells, close by
The nervous system uses a combination of chemical
and electrical signals for long-distance cell-to-cell
communication.
______ are chemical signals secreted by neurons
______, ______, ______.
Neurocrines / Neurotransmitters, Neuromodulators, Neurohormones
______ are chemicals secreted by neurons that diffuse across a small gap to the target cell. ______ use electrical signals as well.
Neurotransmitters / Neurons
Signal pathway - When does a cell responds to a particular chemical signal? What is an example of this?
Only if the target has a receptor, a binding protein.
Hormones are secreted by endocrine glands or cells into the blood. Only target cells with receptors for the hormone will respond to the signal.
What is the signal pathway?
The signal pathway:
* The chemical signal is a ligand that binds to the
receptor and is the first messenger
* Ligand-receptor binding activates the receptor
* The receptor activates one or more intracellular
signal molecules
* The last signal molecule modifies existing proteins or
initiates the synthesis of new proteins
Signal Pathways: Receptor locations
* ______ signal molecules diffuse through the cell membrane
Bind to receptors in the ______ or nucleus.
* ______ signal molecules bind to receptors on the cell
membrane.
Lipophilic / Lipophobic / cytosol
What are the four groups of membrane receptors?
- G protein-coupled
- Receptor-enzymes
- Integrin receptors
- Ligand-gated
Transmission of signal from one side of the membrane to
the other is called _______ ______.
signal transduction
______ ______ allows a small amount of signal to have a large effect. One ______ is ______ into many intracellular molecules.
Signal amplification / ligand / amplified
Figure 6.6c - Signal Transduction: Cascades and
Amplification
cAMP
cGMP