Cell Physiology Cont'd Flashcards Preview

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Flashcards in Cell Physiology Cont'd Deck (40)
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1
Q

Types of Receptors:

what are 3 other ex of ligand-gated receptors?

A

5-HT3
GABAa
Glutamate

2
Q

Types of Receptors:

what are receptors that control membrane bound enzymes called?

A

metabotropic receptors

3
Q

Types of Receptors: Metabotropic receptors

how do they work

A

when a ligand attaches to its receptor , an enzyme on the cytoplasmic surface (inside) of the membrane is activated a reaction inside the cell is accelerated by the enzyme

4
Q

Types of Receptors: Metabotropic receptors

what are the most common type of receptors that control membrane bound enzymes

A

G-protein coupled receptors

5
Q

Types of Receptors: Metabotropic receptors

what are examples of the receptors

A
GPCR
7-transmembrane
Serpentine
Muscarinic ACh receptors (are GPRC)
most adrenergic receptors
6
Q

Types of Receptors:
what type of receptors are integral plasma membrane proteins that when activated by a ligand are either enzymes themselves or part of an enzymatic complex.

A

Catalytic receptors

7
Q

Types of Receptors:

what are ex of catalytic receptors

A

Insulin
EPO
ANP

8
Q

Types of Receptors:

what type of receptors are proteins located in the cytosol or nucleus, are ligand-activated transcription factors.

A

Nuclear (intracellular) receptors

9
Q

Types of Receptors:

how do Nuclear (intracellular) receptors work

A

link extracelular signals to gene transcription in the nucleus of the cell

10
Q

Types of Receptors:

what type of drugs exert their cellular effects via the nuclear receptors

A

Steroid hormones

11
Q

What spans the thickness of the lipid bilayer

A

channels

12
Q

Proteins that span the membrane are called what?

A

integral or transmembrane proteins

13
Q

Chemicals that attach to the receptors of the cell membrane are called _____

A

ligands

14
Q

Ligands act as what (first or second messengers)?

A

first messengers

15
Q

Receptor sites are usually located where?

A

outside the cell

16
Q

membrane enzymes are generally anchored where?

A

inside the cell

17
Q

Chemicals generated inside the cell by enzymes facing inward from the cell membrane are called what? (1st or 2nd messengers)

A

Second messengers

18
Q

what is the 1 exception to the 2nd messengers. All second messengers are released into the cell except this one?

A

Acetylcholinesterase

-projects outward into the synaptic cleft so it can metabolize ACh

19
Q

take home message about receptors:

A membrane receptor usually either operates as a _____ or controls an ______

A

Channel

Enzyme

20
Q

Signal transduction:

what is it

A

the relaying of a message from the exterior to the interior of the cell

21
Q

Signal transduction:
Signal transduction using receptors involves the action of an intermediary protein messenger, which transfers the signal from the receptor to an enzyme. ___ Proteins are the best known proteins for relaying messages from receptors to enzymes

A

G proteins

22
Q

what is the name of the membrane stimulatory protein

A

Gs

23
Q

What is the name of the membrane inhibitory protein

A

Gi

24
Q

on the exterior the 1st messenger attaches to the receptor and Gs or Gi relays or shuttles information to an enzyme. What is the enzyme that it is usually shuttled to?

A

adenylate cyclase

25
Q

what is the function of the Na+ K+ pump ATPase pump

A

keep intercellular K+ high and Intracellular Na+ low

26
Q

The Na+ K+ pump uses energy derived from the breakdown of ATP to go through a series of shape changes , ultimately moving __ Na+ ions out of the cell in exchange for __ K+ ions that are transported into the cell

A

3 Na+

2 K+

27
Q

Remember

How many Na+ And K+ are exchanged

A

3 Na+ extruded

2 K+ imported

28
Q

An ____ fits into a receptor and then makes something happen.

A

Agonist

29
Q

A _____fits into a receptor but has no direct effect. it prevents the agonist from attaching to the receptor so nothing happens

A

Antagonist (competative)

30
Q

Resting Potential:

where are leaky K+ channels located

A

lipid bilayer

31
Q

Continuosly open (Leaky) K+ channels are located in the lipid bilayer and permit what?

A

outward diffusion of K+ down the concentration gradient

32
Q

What controls the RMP

A

K+

33
Q

with acute hyperkalemia the diffusion gradient for K+ in reduced, b/c the rate of diffusion out of the cell is decreased what happens to the RMP?

A

the resting potential is diminished aka the cell depolarizes (RMP goes from -70 to -60)

34
Q

With hypokalemia the diffusion gradient for K+ is enhanced, b/c the rate of diffusion out of the cell is increased, what happens to RMP?

A

The resting potential is increased the cell hyperpolarizes

– RMP goes from -70 to -80

35
Q

with polarity the (-) negative sign in front of the numerical value for the Resting potential indicated the what?

A

Polarity
thus hyper polarized is MORE neg
and Hypo or depolarized is more Positive

36
Q

State the steps of an Action potential

A

A) RMP at -70mV when the nerve axon depolarizes to threshold the FAST Na+ VOLTAGE GATED CHANNEL snaps open
B) a massive and abrupt depolarizations occurs as Na+ influxes ( RMP +30mV)
C) the fast voltage gated Na+ channels quickly shits in the inactivated state and the voltage gated K+ channels open the diffusion ok K+ out causes repolarization and restoration of the RMP at -70mV
D) the Na+ K+ pump extrudes Na+ that entered the cell a d recaptures the K+ that was lost thus restoring ionic balance
** the leaky K+ channels constantly leak K+ out of cell)
See page 8 in sweat book for a diagram

37
Q

in the neuron the voltage gated Na+ channels are located princiably where?

A

the axon and concerted in the nodes of ranvier

38
Q

what is the term for the period when the gated sodium channel is in the inactivated state?

A

absolute refractory period

39
Q

Know this!!!

When are 3 important clinical example r/t the absolute refractory period (inactivated state)

A

1) cardioplegia
2) SCh administration
3) LA administration

40
Q

Memory master pages

A

IA3a-b

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