M2 Membranas

Question 1

which organism’s membrane does not contain a bi-layer?

Answer 1

Archea

Question 2

composition of sphingosine?

Answer 2

Ceramide, lipid, choline and PO4

Question 3

22: 4 /_\ 8 ω-9 is the nomenclature for a fatty acid. What does each part mean?

Answer 3

22- number of carbon atoms
4- number of double bonds
/_\ 8 - position of double bond
ω-9 - position of the last double bond until the end of the chain.

Question 4

what are proteins which are covalently bound to lipids called(em portugues)

Answer 4

proteinas ancorradas a lipidos

Question 5

which of these ions are more inside the cell than outside?
k+, nA+, mG2+, h+, Cl-

Answer 5

K+

Question 6

which ions have more extracellular concentration?

Answer 6

Na+, H+, Mg 2+, Ca2+

Question 7

arrange these in order of increasing permeability to the cell
Glycerol,urea, H20, O2, steroid hormones, Na+, glucose,sucrose, H+, Cl-

Answer 7

Na+,H+,Cl-,— Glucose,sucrose—H2O, Urea, glycerol—O2, steroid hormones

Question 8

what kind of molecules ais the membrane impermeable to? why?

Answer 8

ions because they have a high degree of hydration due to the charge

Question 9

What favours the permeablility of the lipid bilayer?

Answer 9

The smaller the molecule and the more hydrophobic or nonpolar makes it more permeable

Question 10

what is the difference between symporters and antiporters?

Answer 10

symporters take energy gotten from molecules going down their gradient to transport molecules against their gradient, both are going in the same direction
while
Antiporters take energy from molecules going against their gradient to transport molecules against their gradient, but both are going in different directions

Question 11

what is the driving force that help active transporters take molecules against their conc gradient?

Answer 11

electrochemical gradient: the combination of the conc gradient of the molecule( the average between where it is high and where it is low) and the membrane potential energy (readiness of the membrane to put the molecules in equal charge so it can be stable)

Question 12

what are co-transporters?

Answer 12

Secondary active transporters: Symporter and Antiporter

Question 13

how does the glucose-Na+ symporter work?

Answer 13

It uses Na+ going down it’s concentration gradient, passively, establishing and electrochemical gradient to give energy to transport glucose against it’s gradient, but in the same direction as Na+

Question 14

what is the name of the symporter that transports glucose with energy from Na+?

Answer 14

GLUT1

Question 15

which types of membrane proteins are specific and saturated?

Answer 15

Co-transporters

Question 16

For active transport, the energy that it needs can only come from ATP, chemical energy
True or false, and why

Answer 16

False, because this type of transport is in plants, where they get solar energy and their specific ATPases use them for transport

Question 17

What are the types of ATP driven pumps?

Answer 17

P, ABC, V, F (pavaf)

Question 18

how do the types of atpases work?

Answer 18

When there is high ATP/ADP ratio, it hydrolyzes ATP to give energy which help transport substrates,
When there is low ATP/ADP ratio, it synthesizes ATP

Question 19

what is the type of ATPase found in mitochondria and chloroplasts?

Answer 19

F-type ATPase; produces ATP energy in them

Question 20

what do you think the sodium-potassium pump takes molecules?
Down or against their gradient?

Answer 20

Both sodium and potassium against their gradients

Question 21

how does the Sodium-potassium pump impact on the membrane potential?

Answer 21

The N-K pump pumps 3 sodium ions out of the cell and lets in 2 potassium ions.
And knowing that potassium has a high concentration inside the cell and sodium has a high conc outside the cell, doing this maintains the membrane potential energy, or charge by keeping the positiveness of each atom which may have been disrupted by other transporters equal

Question 22

where does glucose have a high concentration?

Answer 22

inside the cell

Question 23

The Sodium-potassium pump acts as a stabilizer of membrane potential destablized by the action of what transporter?

Answer 23

GLUT1 (symporter of glucose)

Question 24

when glucose is symported into the cell, how is it exported out (in the case of need in the blood

Answer 24

Through a uniporter taking it passively (from high to low) to the extracellular fluid

Question 25

which type of pump consumes a lot of energy in the cell?

Answer 25

Sodium-Potassium pump

Question 26

In vertebrates, ann ABC transporter can be found where?

Answer 26

Endoplasmic reticulum

Question 27

Aquaporins are permeable to water and ions. True or false

Answer 27

False. They are permeable to water but impermeable to ions

Question 28

In most animal cells, why is osmosis not used much in regulating the volume of a cell?

Answer 28

Because most of the cytoplasm is not in watery state but gel like state

Question 29

Why can’t aquaporins conduct ions?

Answer 29

They contain hydrophobic amino acids on the other side of the pore which makes it impermeable to ions

Question 30

which type of membrane protein have very fast transport and are not saturated

Answer 30

Ion channels

Question 31

A abertura dos canais é regulada em
resposta a estímulos, que podem ser eléctricos, mecânicos ou ligandos
Verdade ou falso

Answer 31

Verdade

Question 32

Os canais de ioes sao nao seletivo
Verdade ou falso?

Answer 32

falso
Sao altamente seletivo

Question 33

how does action potential work?

Answer 33

Normally, without the presence of voltage gated channels, there will be no action potentials, this is because by having specific voltages which enable them open or close, they are able to stretch the signal across longer distances