BSI Lecture 13 Membrane Transport part 2

Question 1

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

Answer 1

saturation

Question 2

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

Answer 2

finite

Question 3

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

Answer 3

true

Question 4

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 ________ _________

Answer 4

concentration gradient

Question 5

Most glucose uptake by cells are done by __________ transport

Answer 5

facilitated

Question 6

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

Answer 6

insulin

Question 7

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

Answer 7

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

Question 8

What other molecules does facilitate diffusion transport besides glucose?

Answer 8

fructose and galactose

Question 9

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

Answer 9

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

Question 10

Facilitated diffusion only happens in efflux. T or F?

Answer 10

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

Question 11

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

Answer 11

rate

Question 12

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

Answer 12

1985

Question 13

How many different sugar transporters are there?

Answer 13

14

Question 14

Sugar transporters are composed of how many transmembrane domain.

Answer 14

12

Question 15

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

Answer 15

aqueous

Question 16

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

Answer 16

hydrogen

Question 17

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

Answer 17

Outside in

Question 18

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

Answer 18

Outside in

Question 19

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

Answer 19

Inside out

Question 20

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

Answer 20

Outside in

Question 21

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

Answer 21

Inside out

Question 22

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

Answer 22

Inside out

Question 23

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

Answer 23

Outside in

Question 24

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

Answer 24

Inside out

Question 25

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

Answer 25

Outside in

Question 26

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

Answer 26

Inside out

Question 27

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

Answer 27

Inside out

Question 28

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

Answer 28

Inside out

Question 29

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

Answer 29

Outside in

Question 30

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

Answer 30

glucose

Question 31

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

Answer 31

Outside in

Question 32

What is another name for "Symport"

Answer 32

cotransport

Question 33

What is another name for "Antiport"

Answer 33

countertransport

Question 34

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

Answer 34

coupled

Question 35

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

Answer 35

secondary active transport

Question 36

Secondary Transport does it directly use ATP?

Answer 36

no

Question 37

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?

Answer 37

Towards the GI tract/Kidney tubules

Question 38

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

Answer 38

SGLT1

Question 39

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

Answer 39

1980 by Wright et al

Question 40

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

Answer 40

14, normal sugar transporter has 12 TMD's

Question 41

The best characterized active transporter is called _______

Answer 41

The Na+-K+ATPase or Sodium Potassium Pump

Question 42

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

Answer 42

False, both gradients are maintained

Question 43

Osmolarity is very important because cell swelling stimulates what transporter?

Answer 43

Sodium Potassium pump

Question 44

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

Answer 44

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

Question 45

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

Answer 45

electrogenic

Question 46

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

Answer 46

hyperpolarization

Question 47

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

Answer 47

to the K+ site

Question 48

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

Answer 48

toxic

Question 49

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?

Answer 49

False, H+ not Na+

Question 50

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

Answer 50

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

Question 51

Which organelle synthesis ATP?

Answer 51

mitochondria

Question 52

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

Answer 52

false, inner membrane

Question 53

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

Answer 53

true

Question 54

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

Answer 54

ATP synthase

Question 55

ATP Synthase forms what as the protons diffuse through it?

Answer 55

ATP

Question 56

T for F? Drugs can freely cross membranes.

Answer 56

false

Question 57

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

Answer 57

primary active transport requiring ATP hydrolysis

Question 58

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

Answer 58

Facilitated transporters or Secondary active transport

Question 59

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 ____ _____.

Answer 59

fluid secretion

Question 60

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)

Answer 60

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

Question 61

What forms of membrane transport would cyanide affect?

Answer 61

primary and secondary active transport

Question 62

What kind of transport do tissues use to uptake glucose?

Answer 62

Na+ coupled transport