Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry 2 > Module 2: Unit 3 > Flashcards

Module 2: Unit 3 Flashcards

1
Q

Define potential

A

Stored energy
Cell membrane- the possibility of ions moving (in or out of cell) creating an action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define electrical potential

A

Difference in the concentration of electrical charge from one point to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define current

A

Flow of charged particles form one point to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define polarized

A

When there is a difference in electrical charge from the inside of the cell membrane to the outside of the cell membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an excitable cell

A

Cells that have an ability to elicit a process (action potential) when there is a change in their resting membrane potential due to a stimulus. If a stimulus is put upon them, we can change the membrane potential

*skeletal muscle, cardiac and cloth muscle are the muscles or the excitable cells that we want to understand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a membrane potential?

A

Difference of electrical potential (voltage difference) between the ICF and ISF

*it is a measurement difference between the outside of the cell and the inside of the cell in regards to, millivots (voltage charge)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

True or false: membrane potentials exist across every cell in the body

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the three types of gated protein channels?

A

Mechanical
Ligand
Voltage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define Resting Membrane Potential

A

Electrical potential difference across the plasma membrane when the cell is in a non-excited state. The membrane potential is at rest. *No Stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the Resting Membrane Potentials of a non-excited neuron?

A

-70 mV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Is -70 mV to -90mV hyperpolarization or hypopolarization?

A

Hyperpolarization
*further from 0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens with depolarization?

A

Membrane potential decreases
RMP becomes a more positive number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens with hyperpolarization?

A

Membrane potential increases (Ex: -70 to -90mV)
RMP becomes a more negative number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does an action potential do?

A

Lead as to the transmission of an electrical impulse (nerve impulse) that travels along the cell’s plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

All of the options are true regarding graded potentials, except?

A. They can be only depolarizing
B. It is a change in the membrane potential
C. The size of the change is proportional to the strength of stimulus
D. Occur due to gated protein channels

A

A,

It is a change in the membrane potential that occurs in the dendrites and soma of the cell body. It helps to stimulate or inhibit the formation of what we call an action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

True or false: Every single cell in the body is excitable?

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the three types of membrane potentials?

A

RMP, Graded potential, Action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the three influences of membrane potentials?

A
  1. Diffusion of ions down their concentration gradient (diffusion potential)
  2. Electrical attraction of cations and anions (Opposites attract)
    -Electrical chemical gradient
  3. Selective permeability of the membrane
    - leak channels

*1 and 2 are referred to as the Electrochemical gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the ion concentration/composition of ISF?

A

Na+ (sodium)
Ca2+ (calcium)
Cl- (chloride)
HCO3- (bicarbonate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the ion concentration/composition of ICF?

A

K+ (potassium)
Phosphates (-)
Proteins (-)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which gated channel functions through binding from a neuro transmitter?

A

Ligand-gated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which gated channel opens due to pressure?

A

Mechanically-gated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which gated ion channel opens due to a response to a change in the charge inside of the cell?

A

Voltage-gated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What differentiates leak channels from gated channels?

A

Leak channels are always open.

*they are open to help achieve electrochemical equilibrium. Once this equilibrium is achieved it is called the equilibrium potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How would you describe the chemical (concentration) gradient?

A

Concentration of an ion between the ICF and ECF
The drive to move down its concentration gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How would you describe electrical (electrostatic) gradient?

A

Charge of an ion (CATION = Positive charge) (ANION = Negative charge)
The drive for cations to be near anions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which ion has a very high number of ion leak channels in the plasma membrane of neurons compared to other ion channels?

A

Potassium (K+)

*and it only allows K+ to leak through (selective)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does the ATPase pump function to do?

A

It pumps sodium out of the cell and pumps potassium back in specifically three sodium ions and two potassium ions back in.

*this is an active transport pump (Using energy to pump ions against their concentration gradient)

29
Q

True or false: All ions including K+ Na+ Cl- and Ca2+ have their own electrical chemical gradient?

A

True

30
Q

What is the calculation used for the equilibrium potential for an ion at a given concentration difference across a membrane?

A

Nernst equation

31
Q

What equation is used to calculate RMP?

A

Goldman Equation

32
Q

What happens if an ion’s concentration changes in the ISF?

A

If it changes in the blood it changes in the ISF. Ex: if Ca2+ levels decrease in the blood because someone isn’t eating enough Ca2+ we will see that actually depolarizing or decreasing the membrane potential

33
Q

What role does the Sodium-Potassium ATPase have in the RMP?

A

Creates and maintains the concentration gradient of K+ across the cell membrane

34
Q

What is the electrochemical gradient?

A

It is the concentration gradient and the electrical gradient with ions wanting to move down their concentration gradient, and also wanting to be close to the opposite charged ion

35
Q

What is the difference between the equilibrium potential and RMP?

A

EP is the calculation of the electrical chemical equilibrium. The EP is the balance of the electrical chemical gradient, and we can use the Nernst equation to provide an ion like charge to the equilibrium potential.
The RMP takes all of the equilibrium potentials, the equilibrium potential of all the ions around the cell and inside the cell, and calculates it into the Goldman equation to get the resting membrane potential.
*The RMP is a value of all of the ions equilibrium potential

36
Q

True or false: a membrane potential is the difference in charge from the extracellular fluid to the intracellular fluid

A

True

37
Q

True or false: all cells in the body are excitable

A

False

38
Q

Where do graded potentials occur in a neuron?
A. Axon terminal
B. Axon
C. Dendrites and soma
D. Axon hillock

A

C

39
Q

The equilibrium potential for an ion is achieved when:

A. The electrochemical gradient is neutralised
B. The net flow of ions through open channels in the plasma membrane is zero
C. The membrane potential reaches +70 mV

A

B

40
Q

What does it mean when a cell membrane is polarized?

A. The electrochemical gradient is established
B. Only one type of ion can pass through the membrane simultaneously
C. There is no charge difference across the membrane
D. There is a difference in electrical charge between the inside and outside of the cell

A

D

41
Q

What is an electrochemical gradient?

A. The combination of a chemical concentration gradient and an electrical gradient of an ion
B. The difference in electrical charge between cations and anions
C. The difference in charge between the ICF and ECF

A

A

42
Q

True or false: Graded potentials involve local changes in the membrane potential of an excitable cell due to a stimulus

A

True,

It occurs at the dendrites of a neuron

43
Q

How to you explain a graded potential?

A

It is either to stimulate or inhibit the formation of an action potential

44
Q

How does a EPSP initiate action potentials?

A

For a EPSP to initiate an action potential, it must change the membranes potential to -55mV at the axon hillock

45
Q

True or false: Graded potentials DEGRADE (lose strength) with Time and Distance

A

True

46
Q

What are the two types of graded potentials and what do they do?

A

Excitatory Post-Synaptic Potential (EPSP): stimulates the formation of AP
*Makes the neuron “easier” to reach the potential threshold at the axon hillock to initiate an action potential.
*decreases membrane potential (Ex: -70mv to -60mv) = depolarization

Inhibitory Post-Synaptic Potential (IPSP): inhibits the formation of an AP *makes the neuron “harder” to reach the potential threshold at the o on hillock to initiate an action potential. *Increases membrane potential (Ex: -70 mV to -90 mV) hyperpolarization

47
Q

Where do EPSPs and IPSPs occur on a neuron?

A

Only in the dendrites and soma region. They have to bind to neurotransmitter to open up that ion channel.

48
Q

What happens when during EPSP when sodium (Na+) gated ligand channels open, and calcium (Ca+) gated ligand channels open?

A

Membrane becomes depolarized and is more likely to reach the membrane potential threshold

49
Q

What happens during IPSP when potassium (K+) gated ligand channels open, and chloride (Cl-) gated ligand channels open?

A

Membranes becomes hyperpolarization and inhibits the ability to reach the membrane potential threshold

50
Q

Name and describe the three types of summation.

A

Summation
The addition of the ESPS and ISPS at a given time. Determines if the neuron will undergo an action potential or become more inhibited

Cancellation Summation Type = IPSP and EPSP graded potentials cancel one another (RMP stays balanced)

Spatial summation type = The combination of IPSPs and EPSPs from MUTLTIPLE neurons simultaneously onto 1 neuron (can lead to cancellation summation type)

Temporal summation type = the combination of IPSPs and EPSPs from ONE neuron onto another neuron

51
Q

*slide 55 of Mod 2: Unit 3 has action and graded potentials compare and contrast chart to look over.

A
52
Q

What option is true regarding graded potentials with neurons?
A. EPSP or IPSP can lead to the development of action potentials
B. Occur in any location on the neuron
C. They degrade with time and distance
D. Associated with voltage gated channels

A

C

53
Q

A graded potential changing a RMP from -70 to -90mv is referred to as?

A

Hyperpolarization

54
Q

Which ligand gated channels, when opened, will lead to:

A. Depolarization
B. Hyperpolarization

A

Depolarization: Na+ and Ca2+
Hyperpolarization: K+ and Cl-

55
Q

Two neuron synapse with another neuron simultaneously one neuron releases a neurotransmitter that causes the opening of a sodium ligand channels and the other causes the opening of potassium ligand gated channels. What will occur and what type of summation is this?

A

Cancellation summation

56
Q

What is the threshold potential?

A

The level of membrane potential that needs to obtained to initiate an action potential

-55mV at the axon hillock

57
Q

Define propagation

A

Once the AP is initiated, it causes depolarization at adjacent sites on the axon’s plasma membrane till it reaches the axon terminal

58
Q

Define refractory period

A

Period during which another normal AP cannot be generated in an excitable cell.
The membrane cannot respond to further stimulation *specifically with the sodium voltage gated channels

59
Q

Action POtenital Steps Slide 76, 79, 80, on mod 2 unit 3. *Look over
- need to understand the depolarization, repolarization and hyperpolarization phases of AP

A
60
Q

Explain what happens during the depolarization phase

A

Membrane potential decreases and becomes more positive due to sodium voltage channels opening

61
Q

Which option explains why the hyperpolarization phase occurs?

A. Calcium voltage gates open up
B. Sodium voltage gates stay open longer
C. Potassium voltage gates start open longer
D. Potassium ligand gates stay open longer

A

C

62
Q

Explain what happens during the repolarization phase

A

Membrane potential increases and becomes more negative due to potassium voltage channels opening

63
Q

How could an AP be inhibited?

A

IPSPs

64
Q

An epidural procedure will introduce medication directly into the meninges the lower back.

True or false

A

False

65
Q

Lidocaine must be in its charged form to be able to pass through the plasma membrane

T or False

A

False

66
Q

This phase/aspect of the AP is associated with sodium-potassium ATPase pump

A. Initiation of the AP
B. Depolarization
C. Repolarization
D. Re-establishment of the RMP

A

D

67
Q

What option defines why Jamal had his skeletal muscle weakness issues?

A. Jamal’s hypokalemia led to a hyperpolarized RMP
B. Jamal’s hyperkalemia led to a depolarization RMP
C. Jamal’s hypokalemia led to a depolarized RMP

A

A

68
Q

What statement is TRUE regarding the case studies in laboratory 01.

A. Lidocaine blocks sodium voltage-gated channels from the IF side
B. Jamal’s hypokalemia disrupted the formation of graded potential, which blocked an AP
C. Changing potassium’s serum concentration will change the potassium’s equilibrium potential

A

C

Biochemistry 2 (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions