CH 15
_________ is the process by which cells internalize materials and retrieve portions of the plasma membrane.
A. endocytosis
B. exocytosis
C. pinocytosis
A
There are four different receptor responses on cells. What are they?
Cell survives, dies, divides, and differentiates
If you upregulate, then that _____ the amount of molecules
If you downregulate, then that ____ the amount of molecules
increase
decrease
microtubules, intermediate filaments, microfilaments, and septin
Compare and contrast an agonist and an antagonist.
agonist: bind and activates
antagonist: binds but does not activate
both are ligands
cis-golgi network: ____ the ER
trans-golgi: _____ the ER
toward the ER
away from the ER/toward the cell membrane
At every step in the cascade, each signaling intermediate stimulates the production of many molecules for the next step. This multiplication of the effect is called
signal amplification
What is a primary ligand?
the main, endogenous ligand for a specific receptor
Which are the largest structural elements in the cytoskeleton?
microtubules
What cytoskeleton element is composed of G-actin monomers?
microfilaments
What is the UPR?
Unfolded protein response;
The misfolded proteins are recognized by several types of transmembrane sensor proteins in the ER membrane, each of which activates a different component of the
This includes inhibition of protein synthesis, and the activation of genes that increase proteins involved in protein folding, quality control, degradation, amino acid metabolism (to recycle the proteins) and, in case it’s necessary, apoptosis.
2. Intracellular Signaling Cascade can have
A. one receptor activate multiple pathways
B. different receptors activate the same pathway
C. different receptors activate different pathways; one pathway affects the other
D. all the above
D
The ability of a cell to respond to ligand-receptor binding by altering the cell’s behavior or gene expression is called
signal transduction
Compare and contrast a FtsZ in most prokaryotes, some prokaryotes, and chloroplasts.
most: has FtsZ
some: has another DTPase
chloro: FTZs inside and outside
The "stereocilia" on the hair cells within the cochlea in the ear are responsible for
the perception of sound.
What is the endomembrane system? Name all the organelles that are involved.
The endomembrane system is group of membranes and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins.
Organelles: Rough ER, vesicles, nuclear envelope, nuclear pores, golgi complex, plasma membrane
Explain how insulin is the signal for my glucose to come into the cell.
Insulin binds to receptor, upregulation and translocation of GLUT4 channels to the plasma membrane where they bind to the bilayer, this allows glucose to enter into the cell
How is it that we can smell different smells?
Chemistry of the "smell' molecules with the use of OR (GPCR for human smells)
Compare and contrast cilia and flagella.
cilia: motile: function in locomotion, feeding, circulation, and aeration; also helps with sensing the external environment; short; outside of the cell
flagella:only help in locomotion, move cells thru a fluid environment; long thread-like appendages on the surface of a cell
Sometimes activated components from one pathway affect components of another pathway. This is called:
crosstalk
Explain the Pulse-Chase experiment.
This experiment helped to define the secretory pathway:
Rough ER to Golgi to secretory vesicles to cell exterior
Exposed the cells to radioactive or fluorescent compounds and observed the flow of movement
Name one Acetylcholine (Ach) receptor and decribe its function.
Nicotinic (nAChR): ionotropic Na+ channel
In skeletal myocytes, receptor activation opens the channels, allowing sodium to enter the cell. This can depolarize the cell, cause an action potential, and trigger contraction.
Muscarinic (mAChR): metabotropic GPCR
In cardiac myocytes, activation of this GPCR leads to intracellular signaling that cause K+ channels to open. This hyperpolarizes the cells, thus delaying contraction.
Explain how a GPCR is activated.
signal molecule send the signal to activate all G sununits, then alpha is by itself, beta and gamma is together,
Intermediate filaments are the ____ stable and the ____ soluble compnents of the cytoskeleton.
A. most, most
B. least, least
C.most, least
D. least, most
C
Draw your favorite cytoskeleton molecule.