Ch 8 Flashcards
An agent that influences the properties of cells is called a(n)
signal
Plant cells produce hormones that determine the pattern of cell elongation such that the plant will grow toward light. The hormone effect is an example of an:
outgoing signal
Cell signaling is important because
- cells need to respond to a changing environment.
* cells need to communicate with each other.
What type of signaling involves signals that pass through a cell junction from the cytosol of one cell to the cytosol of an adjacent cell?
Direct Intercellular signaling
during ____ dependent signaling, membrane-bound signals bind to receptors on adjacent cells.
contact
the process thru which cells can detect, interpret, and respond to signals in their environment
-included incoming and outgoing signals
Cell communication
An example of an incoming signal in cell communication is:
ultraviolet light
Cell signaling allows cells to detect and respond to signals from their ___ and from other cells
environment
Signals passing through a cell junction from the cytosol of one cell to an adjacent cell is a description of ___ _____ ______
direct intercellular signaling
If a cell secretes a signal that binds to its own receptors or those of neighboring cells of the same time, the process is called signaling.
autocrine
Membrane-bound signals bind to receptors on adjacent cells in the following signaling mechanism known as
contact dependent signaling.
In signaling, a cell secretes a signaling molecule that does not affect the cell secreting the signal but influences the behavior of target cells in close proximity.
Paracrine
Which signaling process occurs when cells release signals that travel long distances through the blood of a vertebrate or the vascular system of a plant?
Multiple choice question.
Endocrine signaling
Cellular signaling involves an interaction between a signaling molecule from one cell and a(n) protein on or in another cell
receptor
The stage of cell signaling that immediately follows receptor activation is called:
signal transduction
When cell density is high, the density of autocrine signals is
high
What is the third and final stage of cell signaling?
Cellular response
In what type of signaling does a specific cell produce a signaling molecule that does not affect the cell secreting the signal but influences the behavior of target cells in close proximity?
Paracrine
Match each step of cell-to-cell signaling with the appropriate description.
i. Receptor Activation = A signaling molecule binds to a receptor.
ii. Signal Transduction = The signal is converted to a different type of signal, often resulting in the production of an intracellular signaling molecule.
iii. Cellular Response = An enzyme, structural protein, or transcription factor is altered.
cells produce hormones that travel long distances or even diffuse through the air to affect other cells.
endocrine signaling
Identify the stage of cell signaling where a signaling molecule binds to a receptor, causing a conformational change in the receptor.
Receptor activation
During cellular signaling, what event causes the receptor to become activated?
A signaling molecule binds to it.
In a ligand-receptor complex, what term stands for dissociation constant?
Kd
What is the second stage of cell signaling?
Signal transduction
The three categories of cell surface receptors are:
enzyme-linked receptors
ligand-gated ion receptors
G-protein-coupled receptors
The last stage of a cell signaling pathway is the
cellular response
Enzyme-linked receptor
The receptor phosphorylates itself or another protein.
G-protein-coupled receptor
An intracellular G protein releases GDP and binds to GTP.
Ligand-gated ion channel =
Ions move across the plasma membrane of the cell.
Steroid hormone recepto
The receptor binds to DNA and activates the transcription of specific genes.
Put the steps involved in a cell-to-cell signaling pathway in the correct order.
- Binding of a signaling molecule to receptor
- intracellular signal transduction pathway
- Cellular response
During the receptor activation stage of cell signaling, a signaling molecule binds to a receptor and causes a change in the receptor.
conformational
When a signaling molecule binds to an enzyme-linked receptor, a conformational change is transmitted through the membrane-embedded portion of the protein. This conformational change causes the intracellular
catalytic domain to become active
What type of interaction occurs between a ligand and its receptor?
Non-covalent and specific
What is the function of protein kinases?
They add phosphate groups to proteins.
Which of the following are types of cell surface receptors?
G-protein-coupled receptor
Ligand-gated ion channel
Enzyme-linked receptor
proteins are intracellular proteins that interact with G-protein-coupled receptors.
G
Enzyme-linked receptor
Activation of the receptor’s catalytic domain
G-protein-coupled receptor
Interaction of the receptor with an intracellular G protein
Ligand-gated ion channel
Formation of an open channel by the receptor
G proteins are so named because of their ability to bind:
GTP and GDP
In the first step of the signal transduction pathway involving cAMP, a signal molecule binds to and activates a receptor called ____
GPCR and
GTP
The change that occurs when a signaling molecule binds to the extracellular domain causes the catalytic domain to become:
active
Activation of a GPCR causes a G protein to bind ___. The activated G protein stimulates adenylyl cyclase to synthesize ___. This second messenger ultimately activates the enzyme ___, which phosphorylates cellular proteins that carry out the cellular response.
GTP; cAMP; PKA
The enzymes that transfer a phosphate group from ATP to specific amino acids in a protein are known as ____
protein kinases
Select the event that occurs last after the activation of a G-protein coupled receptor.
A G protein hydrolyzes GTP to GDP.
Intercellular proteins that bind guanosine triphosphate (GTP) and
G - proteins
When a signaling molecule binds to a(n) _______-gated ion channel, the channel opens and allows the flow of ions through the membrane
ligand
What proteins can bind GTP and GDP?
G-Protein
Some signaling molecules must pass through the ____ ____ before activating a receptor located in the cytosol or the nucleus.
plasma membrane
the binding of a signaling molecule activates
GPCR
the G protein binds to
GTP
the α subunit dissociates from
β/γ dimer
Put the steps involved in a signal transduction cascade involving a G-protein-coupled receptor in the correct order.
1) A ligand binds to to a G-protein-coupled receptor.
2) An intracellular G protein binds to GDP.
3) Adenylyl cyclase synthesizes cAMP.
4) Protein kinase A is activated.
5) Cellular proteins become phosphorylated and cause a cellular response.
When an estrogen-receptor complex is formed, it undergoes a conformational change, which allows it to form a dimer with another estrogen-receptor complex. What does this dimer activate when it binds with DNA?
The transcription of specific genes
Put the events that occur during the activation of a G-protein-coupled receptor in the correct order, beginning with the first event at the
- a signaling molecule binds to a GPCR.
- the GPCR binds to a G protein
- the G protein exchanges GDP for GTP
- The G protein subunits dissociate
What happens when a signaling molecule binds to a ligand-gated ion channel?
The channel opens and allows the flow of ions through the membrane.
