BIO 360 - Exam 1 - Chapter 6 Summary and Outline Questions Flashcards
Chapter 6 Summary Questions
There are two basic types of physiological signals: ______ and ______. ______ signals are the basis for most communication within the body.
chemical and electrical / Chemical
There are four methods of cell-to-cell communication:
(1) direct cytoplasmic transfer through gap junctions.
(2) contact-dependent signaling.
(3) local chemical communication.
(4) long-distance communication.
______ ______ are protein channels that connect two adjacent cells. When they are open, chemical and electrical signals pass directly from one cell to the next.
Gap junctions
______-______ ______ require direct contact between surface molecules of two cells.
Contact-dependent signals
Local communication uses ______ signals, chemicals that act on cells close to the cell that secreted the paracrine.
A chemical that acts on the cell that secreted it is called an ______ signal.
The activity of ______ and ______ signal molecules is limited by ______ distance.
paracrine / autocrine / paracrine and autocrine / diffusion
Long-distance communication uses ______ molecules and electrical signals in the nervous system.
Long-distance communication uses ______ in the endocrine system.
Only cells that possess receptors for a ______ will be target cells.
neurocrine / hormones / hormone
______ are regulatory peptides that control cell development, differentiation, and the immune response. They serve as both local and long-distance signals.
Cytokines
______ ______ ______ use membrane receptor proteins and intracellular second messenger molecules to translate signal information into an intracellular response.
Signal transduction pathways
Some signal transduction pathways activate ______ ______. Others activate ______ ______ that create second messenger molecules.
protein kinases / amplifier enzyme
Signal pathways create intracellular ______ that amplify the original signal.
cascades
______-______ ______ channels open or close to create electrical signals.
Ligand-gated ion
___ ______ linked to amplifier enzymes are the most prevalent signal transduction system. ___-______ coupled receptors also alter ion channels.
G proteins / G protein
Calcium is an important signal molecule that binds to ______ to alter enzyme activity. It also binds to other cell proteins to alter movement and initiate exocytosis.
calmodulin
Receptors come in related forms called ______. One ligand may have different effects when binding to different ______.
isoforms
A receptor may have multiple ligands. Receptor ______ mimic the action of a signal molecule. Receptor ______ block the signal pathway.
agonists / antagonists
Receptor proteins exhibit _______, ______, and ______.
specificity, competition, and saturation.
Cells exposed to abnormally high concentrations of a signal for a sustained period of time attempt to bring their response back to normal through down-regulation or by desensitization.
In ______-______, the cell decreases the number of receptors.
In ______, the cell decreases the binding affinity of the receptors.
______-______ is the opposite of down-regulation and involves ______ the number of receptors for a signal.
down-regulation / desensitization / Up-regulation / increasing
Cells have these two mechanisms for terminating signal pathways.
(1) removing the signal molecule
(2) breaking down the receptor-ligand complex.
In ______ ______ pathways, an integrating center makes the decision to respond to a change.
A chemical or electrical signal to the target cell or tissue then initiates the response.
Long-distance reflex pathways involve the ______ and ______ ______ and ______.
reflex control / nervous and endocrine systems and cytokines.
______ ______ is faster and more specific than ______ ______ but is usually of ______ duration. ______ control is less specific and slower to start but is longer lasting and is usually amplified.
Neural control / endocrine control / shorter / Endocrine
Chapter 6 Outline Questions
______ signals are changes in a cell’s membrane potential. ______ signals are molecules secreted by cells into the extracellular fluid. The cells that respond to ______ or ______ signals are called ______ cells.
Electrical / Chemical / target
______ signals are responsible for most communication within the body. ______ signals act as ______ that bind to proteins to initiate a response.
Chemical / Chemical / ligands