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Biochem Objectives
N/A
38
Other
Graduate
10/05/2009

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Cards

Term
What type of receptor is used most often?
Definition
Cell surface receptor
Term
What type of molecules use Cell surface receptors and where are they located?
Definition

-Large hydrophilic

-located in plasma membrane

Term
What type of molecules use intracellular receptors?
Definition
Small hydrophobic
Term
Describe how intracellular receptors work
Definition
They must be carried through blood by a carrier protein to the cell where they are released and diffuse through membrane to receptor (usually in nucleus)
Term
How does contact dependent signal molecule work? Is it popular?
Definition

The signal cell must touch the target cell, bc of this no signaling molecule is needed.

 

-Not prevalent

 

Term
What are the 6 steps of signal transduction?
Definition

1. synthesis of signal molecule from secretory cell

2. release signal molecule into blood/fluid in low concentrations

3. transport signal molecule

4. detection/binding of signal molecule to specific receptors

5. induction of the response

6. termination of the response

Term
How does paracrine signal molecules work? What are they dependent on?
Definition

Locally act with other target cells/local mediators.

 

-Dependent on signal being released into extracellular space.

Term
How does synaptic signal molecules work? 
Definition

A nerve cell and target cell must be in close contact to generate a signal that is transmitted electrically to synapse where the Nts are released.

 

-Usually only a target cell is exposed to Nts.

Term
How does endocrine signal molecules work? 
Definition
Endocrine cell releases a hormone into the blood where it travels to the specific target cell that recognizes them via specific receptors and "pulls" them from the blood.
Term
A cell only reacts to a signal if it has the...
Definition
specific  receptor for the signal
Term
Complexity arises bc 1 signal binding to 1 type of receptor protein can cause...
Definition
many different effects in the target cell and bc they can occur simultaneously. 
Term
Some examples of the different effects that can arise bc of signaling complexity include:
Definition

-Acetylcholine in heart muscle cells can decrease the rate

 

-Salivary gland can cause secretion

 

-Skeletal muscle can cause contraction

 

Term
Another reason for signaling complexity is that cells have different receptors that can..
Definition
make it simultaneoulsy sensitive to many different signals since signals can interact and intracellular relay systems can interact.
Term
What are the 6 functions of signaling cascade?
Definition

1. transfer signal- outside of cell transfers to inside of cell

2. transform signal into molecular form

3. amplify signal (most of the time)

4. distribute signal in parallel to others in a divergent manner

5. modulate how signal behaves based on conditions

6. downstream of the cascade

 

Term
A signal molecule is also called a...
Definition
ligand
Term
List some of the best know hydrophobic signaling molecules 
Definition

-cortisol

-NO

-vitamin d

-testosterone

-Retinoic

-estradiol

Term
Cortisol acts on ________ of proteins, carbs and lipids
Definition
metabolism
Term
Cortisol is made in the 
Definition
adrenal gland
Term
What are the 5 steps of cortisol signaling?
Definition

1. diffuses across the plasma membrane

2. binds to intracellular receptor protein

3. conformational change activates receptor protein

4. activated receptor complex moves into nucleus

5. activates target gene at regulatory region which activates transcription 

Term
What are the effects of cortisol on the body?
Definition

Increase blood pressure and glucose concentration resulting in quick burst of energy.

 

Can also be released during stress fight/flight

Term
What do ion channel receptors do?
Definition
Generate flow of ions to produce an electrical effect
Term
How do ion channel receptors work?
Definition

1. ligand binds to receptor

2. receptor changes shape

3. receptor can now open and close for specific ions

Term
Chemical signal is transduced into an electrical signal in the form of a _______ change across plasma membrane 
Definition
voltage
Term
What type of molecules utilize ion channel receptors?
Definition
Small molecules NTs and some neuropeptides
Term
Give an example of ion channel a receptor reaction 
Definition
When nicotinic adds to sodium the receptor changes shape. Once it disassociates the receptor changes shape again to close/stop the flow.
Term
Define G protein linked/enzyme linked receptors
Definition
-generates activated form of membrane bound protein that is released to diffuse in the plane of the plasma membrane to initiate cascade
Term
What's the largest class of extracellular receptors
Definition
G protein linked
Term

What receptors use cascades?

 

Definition

- G Protein linked receptor

-Enzyme linked receptor 

Term
In G protein receptors what are ore common protein or enzyme linked?
Definition
Protein
Term
Signaling proteins act as
Definition
on/off switch
Term
Kinase
Definition
adds on a phosphate to a signaling molecule to turn it on
Term
Phosphatase
Definition

deletes on a phosphate to a signaling molecule to turn it off

Term
Whats the most common type of plasma membrane receptor?
Definition
G linked protein
Term
What are the 2 major classes of molecular switch proteins?
Definition

-phosphorylation

-GTP binding proteins

Term
G protein linked receptors mediate responses of:
Definition
alot of extracellular signaling molecules: NTs, hormones, local mediators
Term
What protein receptor is used most often in drugs?
Definition
G linked protein receptors
Term
How many helices are on the G linked protein receptor
Definition
7 alpha helices
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