BSI Lecture 13 Membrane Transport part 2 Flashcards

1
Q

All carrier-mediated transport systems (excluding ion channels) exhibit _______ kinetics.

A

saturation

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2
Q

Saturation Kinetics is due to a _________ number of transporter molecules.

A

finite

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3
Q

T or F? When multiple substances are transported, the binding of one substance often enhances subsequent binding.

A

true

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4
Q

In facilitated transport, a substance is normally impermeable to the membrane and uses a form of transport that relies purely on the flow of a substance down it’s ________ _________

A

concentration gradient

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5
Q

Most glucose uptake by cells are done by __________ transport

A

facilitated

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6
Q

_________ exerts its effects by increasing the number of transporter molecules in the cell membrane.

A

insulin

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7
Q

Insulin exerts its effects by changing the kinetics or turning transporters “on.” T of F?

A

False. It increases the number of transporter molecules in the cell membrane.

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8
Q

What other molecules does facilitate diffusion transport besides glucose?

A

fructose and galactose

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9
Q

After the glucose binds to the receptor site, what happens next?

A

Conformational change resulting in the glucose facing the opposite side of the membrane.

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10
Q

Facilitated diffusion only happens in efflux. T or F?

A

False, transport can usually occur in either direction depending on the gradient, (if not coupled).

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11
Q

After release of the transported sugar, the transporter must re-orientate back to its original conformation, this is probably the _____ Limiting Step.

A

rate

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12
Q

What year was the first GLUT transporter protein cloned and found to be 492 AA monomer constitutively expressed in virtually all cells.

A

1985

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13
Q

How many different sugar transporters are there?

A

14

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14
Q

Sugar transporters are composed of how many transmembrane domain.

A

12

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15
Q

In a sugar transporter, each transmembrane domain (TMD) is compose of an alpha-helix with a central _______ pore for sugar to pass.

A

aqueous

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16
Q

Sugar transport substrate specificity appears to be determined by_________ bonding between specific sugar hydroxyl groups and the hydrophilic AA side-groups lining the binding site

A

hydrogen

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17
Q

Coupled transport slide: Ion Channels: Which way does Ca2+ flow?

A

Outside in

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18
Q

Coupled transport slide: Ion Channels: Which way does Cl- flow?

A

Outside in

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19
Q

Coupled transport slide:Ion Channels: Which way does K+ flow?

A

Inside out

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20
Q

Coupled transport slide: Ion Channels: Which way does Na+ flow?

A

Outside in

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21
Q

Coupled transport slide: Primary Active Transport: Which way does H+ flow?

A

Inside out

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22
Q

Coupled transport slide: Primary Active Transport: Which way does Na+ flow?

A

Inside out

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23
Q

Coupled transport slide: Primary Active Transport: Which way does K+ flow?

A

Outside in

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24
Q

Coupled transport slide: Primary Active Transport: Which way does Ca2+ flow?

A

Inside out

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25
Q

Coupled transport slide: Secondary Active Transport: Which way does amino acid flow?

A

Outside in

26
Q

Coupled transport slide: Secondary Active Transport: Which way does H+ flow?

A

Inside out

27
Q

Coupled transport slide: Secondary Active Transport: Which way does Ca2+ flow?

A

Inside out

28
Q

Coupled transport slide: Secondary Active Transport: Which way does HCO3- flow?

A

Inside out

29
Q

Coupled transport slide: Secondary Active Transport: Which way does Cl- flow?

A

Outside in

30
Q

Coupled transport slide: Facilitated Diffusion: Which substance does facilitated diffusion that is not an Ion?

A

glucose

31
Q

Coupled transport slide: Facilitated Diffusion: Which direction does glucose flow?

A

Outside in

32
Q

What is another name for “Symport”

A

cotransport

33
Q

What is another name for “Antiport”

A

countertransport

34
Q

When two substances are transported together by the same transporter the transport is said to be ________.

A

coupled

35
Q

When a substance coupled and moved against its gradient by means of another substance moving with its gradient is called??

A

secondary active transport

36
Q

Secondary Transport does it directly use ATP?

A

no

37
Q

Sodium is coupled w/AA or Glucose which are absorbed against their gradient to the GI tract and Kidney tubules, no ATP is required, which direction Na+ flowing?

A

Towards the GI tract/Kidney tubules

38
Q

Cotransporter of Na+ and glucose is the _______. (transporters name)

A

SGLT1

39
Q

The symporter Na+ and glucose is called the SGLT1, what year was it cloned and by whom?

A

1980 by Wright et al

40
Q

How many TMD’s does SGLT1 have and how is it different from other transporter?

A

14, normal sugar transporter has 12 TMD’s

41
Q

The best characterized active transporter is called _______

A

The Na+-K+ATPase or Sodium Potassium Pump

42
Q

T or F? In the sodium potassium pump, only the Na+ gradient is maintained.

A

False, both gradients are maintained

43
Q

Osmolarity is very important because cell swelling stimulates what transporter?

A

Sodium Potassium pump

44
Q

Sodium Potassium Pump moves ions evenly (balanced) through it’s pump. T or F

A

False, 3 sodium ions are moved out and 2 potassium ions are moved in

45
Q

Producing a change in the electrical potential of a cell is called ________

A

electrogenic

46
Q

The sodium potassium pump makes the cell ELECTROGENIC which increases the membrane potential slightly this causes an ~-4 mV _________ in neurons.

A

hyperpolarization

47
Q

Sodium Potassium Pump can be blocked by ouabain which binds _____ _____.

A

to the K+ site

48
Q

Ca2+ functions as a secondary messenger and is _____ at high levels.

A

toxic

49
Q

In the parietal cells of the stomach, distal tubules, and collecting ducts of the kidneys, Na+ are transported against their gradients to aid in digestion and reverse acidosis. T or F?

A

False, H+ not Na+

50
Q

The amount of energy required depends on the gradient produced, energy required is described by what equation?

A

Energy (calories/osmole) = 1400 log (C1/C2)

51
Q

Which organelle synthesis ATP?

A

mitochondria

52
Q

The mitochondrial outer membrane contains the electron transport system (ETC). T or F?

A

false, inner membrane

53
Q

In the mitochondria, H+ are pumped against their electrochemical gradient. T or F?

A

true

54
Q

Mitochondria: The proton pump allows H+ ions to diffuse back across the inner membrane through what enzyme?

A

ATP synthase

55
Q

ATP Synthase forms what as the protons diffuse through it?

A

ATP

56
Q

T for F? Drugs can freely cross membranes.

A

false

57
Q

One principle transporter “super families”, ATP Binding Cassettes (ABCs) affecting drug uptake, uses which transport method?

A

primary active transport requiring ATP hydrolysis

58
Q

Solute Linked Carriers (SLCs), another “super families” operates as which transport method(s)?

A

Facilitated transporters or Secondary active transport

59
Q

Cystic fibrosis is caused by a single gene mutation that encodes for the cystic fibrosis transmembrane regulator (CFTR) which is an epithelial chloride channel and affects ____ _____.

A

fluid secretion

60
Q

If to co-transport of X out of a cell required it be linked to K+ movement what type of transport/transporter would this be? (transporter does NOT use ATP)

A

Secondary active transport/coupled symport; linked to K+ efflux (K+ gradient maintained by primary active transport)

61
Q

What forms of membrane transport would cyanide affect?

A

primary and secondary active transport

62
Q

What kind of transport do tissues use to uptake glucose?

A

Na+ coupled transport