Topic 3 - Membrane Protiens Flashcards Preview

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Flashcards in Topic 3 - Membrane Protiens Deck (59):
1

Plasma membrane consists of ________

Phospholipids and protein

2

Hydrophilic heads align to ______

Extracellulaur space or cytoplasm

3

Examples of hydrophobic molecules and how they pass though

O2/CO2/N2 and steroid hormones
Pass through readily

4

Examples of small uncharged polar molecules and how they pass thorough

H2O/urea/glycerol
Pass through readily BUT at a lower rate as they are capable of dissolving

5

Large uncharged polar molecules - examples and how they pass

Glucose/sucrose
Can not pass through

6

Transmembrane proteins act as ______or ______

Channels or transporters

7

What is the function of these channels or transporters

Aid and control the movement of substances. They help control ion concentrations and concentration gradients

8

Examples of protein free bilayers

H+/Mg2+/Ca2+/HCO3-

9

What is facilitated diffusion

Small molecules that could only move only slowly by passive diffusion speeded through the membrane using transmembrane channel proteins that are specifically shaped to that molecules

10

What are gated channels

Channels protein always open using the help of an change in confirmation of the protein to open the channel

11

Example of gated channel

Sodium potassium pump

12

What’s a ligand gated channel

Binding of a signal molecule to change the confirmation of the channel

13

An example of it

Sodium or potassium channels

14

What’s a voltage gated channel

Uses changes in ion concentration to determine the opening and closing of channel

15

Where are they found

Nerve cells

16

What is signal transduction

Uses receptor proteins on the surface that are altered by the binding of the signal then sets off he reaction within the cell

17

What are the two types of binding sites for glucose symport

One for sodium
One for glucose

18

What’s the effects of the binding of one

It enhances the binding of another

19

What’s drives the system and how is that generated

Driven by sodium gradient generated by the sodium/potassium ATPase

20

How is it described

Secondary active transport

21

What happens when all binding sites are filled

Conformational change delivers both molecules across the membrane

22

What happens next

Sodium is pumped back out of the cell by sodium/pottasium ATPase

23

Why is sodium pumped back out

The conformational change relies on both sets of sites being filled or not and the switch between stars only happens if all sites are full or empty

24

How does this transport protein exist

In two states, A and B

25

Why is glucose more likely to bind to the molecule in the A state rather than the B state

Much higher extracellulaur than intracellulaur sodium levels

26

_____ glucose and sodium enter the cell by _______ transitions

More
A-B

27

What is this an example of

Cooperative co-transport

28

The net flow results in ________ against the concentration gradient

Accumulation of glucose

29

Sodium ions flow ____ their electrochemical gradient while glucose molecules pumped ___ their concentration gradient

Down
Up

30

What is the sodium/glucose symport used for

Actively transport glucose out of the intenstine and into the kidney tables and back into the blood test

31

What does the sodium potassium ATPase pump do

Transports ions against a steep concentration gradient using emerged from ATP

32

What does it use ATPase to do

Remove phosphate from ATP and uses it to change the confirmation of the protein channel

33

Stage 1 of sodium potassium pump

Transporter has high affinity for sodium ions inside the cell

34

Stage 2 of sodium potassium pump

Binding occurs

35

Stage 3 of sodium potassium pump

Phosphorylation of ATP

36

Stage 4 of sodium potassium pump

Confirmation changes

37

Stage 5 of sodium potassium pump

Affinity for ions change

38

Stage 6 of sodium potassium pump

Sodium ions released outside of the cell
Potassium ions bind outside the cell

39

Stage 7 of sodium potassium pump

Dephosphorylation

40

Stage 8 of sodium potassium pump

Confirmation changes

41

Stage 9 of sodium potassium pump

Potassium ions taken into the cell

42

Stage 10 of sodium potassium pump

Affinity return to start

43

Functions of the pump

Maintain osmotic balance
Generates ion gradient in kidney tumbles/for glucose symport in the small intestine
Generates and maintains ion gradient for resting potential in neurons

44

Electrical impulses travel along a ___________ as channel proteins ____ to allow ______ to rush in down a ________ ________

Nerve cell
Open
Sodium ions
Concentration gradient

45

What’s the name of the tiny gaps that prevents nerve impulses jumping directly to the next nerve cell

Synapse

46

What is responsible for carrying the signal across the gap

Neurotransmitters

47

What on the other side of the gap

Protein receptorsinked to closed ion channel proteins

48

What does the binding of neurotransmitters cause

Opening o the ion channels to allow sodium ions to rush in and the signal travels down the next neuron

49

When a neurotransmitter binds to a protein receptor a _______ ________ causes _______

Confirmation change
Ion channel to open and allow sodium ions to rush in

50

The neurotransmitters binding to its red world is an example of

A ligand gated channel

51

The flow of ions into the post synaptic membrane as a result of ?

Neurotransmitters binding leads to a change in charge across the membrane

52

The change in charge is known as ?

Depolarisation

53

What does he change in charge trigger

Opening of further ion channels (sodium/potassium ATPase) along the axon of the nerve (voltage gated channels)

54

What is the result

Charge moving along the axon towards the next nerve

55

Charge moving along the axon towards the next nerve is known as

Propagating

56

The wave of depolarisation reaches the end and tiggers?

The release of a neurotransmitter

57

Once the wave has passed ____________ close and other open to move ions in the opposite direction

Sodium channels

58

This then rest the neuron to its ________

Resting potential

59

What is the resting potential

Charge before depolarisation