Membrane Plasmique Part 2 Flashcards
What are the different types of proteins that you may find associated at the membrane?
Transmembrane
*Interseque:
Membrane associated
Tied to a lipid
*Peripherique:
Tied to another protein
How might we get a hydrophilic pore?
Plusieurs hélices-𝛼 peuvent former un pore hydrophile
where the outsides are hydrophobes
What are the 4 common transmembrane proteins?
Transporters
Protein d’ancrage
Receptors
Enzymes
What are the different classes of transmembrane receptors?
Ionic Channels,
GPTase bound Receptors,
enzyme coupled receptors
TRUE OR FALSE, the transmembrane phospholips can act as secondary messengers in certain conditions.
TRUE
IP3
What are the molecules that can pass the membrane freely?
Petites molecules hydrophobes (gas,O2, CO2, N2)
petites molecules polaire (glycerol, ethanol)
Can ions pass the membrane?
NO
Can glucose pass the membrane?
HELL NO
What is the difference between passive and active transport?
Passive: towards the [gradient], no energy
Active: Againts the [gradient], requires energy
What are the two kinds of passive transport and what is the difference?
Simple Diffusion:
Assisted Diffusion:
Facilitated diffusion is saturable -> nmb of transporters vs nmb of molecules
Uses another molecure to transport the target
~What are the two kinds of active transport?
Active and Vesicular
What are the properties of active diffusion?
Active diffusion -> against the [] gradient,
saturable,
needs energy
What is the difference between an ion and a glucose molecule in relation to facilitated diffusion?
Glucose uses the concentration gradient
And Ion will use the charge gradient mainly
For an ion the [] is less important than the membrane potential (both together)
What are the main ions setting the membrane potential?
Na and K+
K+ inside Na outside
What controls the Na K concentrations? What kind of transport is this?
Main Na+ K+ controller -> The NA/K pump
(for every ATP 3 sodium out and 2 Potassium in)
Active transport
What kind of active diffusion is that of NaK transporter and why?
Primary as they use ATP directly
What is an analogy to use with Na K in relation to their energy?
The NA outside the cell is like a dam of potential energy that really wants to flow inside the cell. This can be used to transport other molecules. This is why it is put outside
What is coupled transportation and what are the 3 kinds?
Please provide 1 example per each kind and the properies.
Simply a transporter that uses two molecules to transfer them. The three kinds are:
Uniport: 1 molecule in 1 direction
Symport : 2 molecules in same direction
SGLT I; sodium-glucose transporter 1;
* Use sodium to insert glucose (see page 55)
* This is active but secondary -> doesn’t use ATP directly but the Na gradient that was created via ATP
Antiport: 2 molecules transported in different directions -> NA/K pump (primary active)
What kind of transporter is SGLT I?
sodium-glucose transporter 1
symport, transport actif secondaire
What kind of transporter is GLUT1 (-14)?
Passif facilitated diffusion
Passive transportation of glucose by using [glucose gradient]
What is the difference between SGLT I and GLUT in terms of location?
SGLT I found apical side
GLUT found basal side
SGLT1 (Sodium-Glucose Linked Transporter 1) is found on the apical side and is responsible for the active transport of glucose across the apical membrane of enterocytes (intestinal cells). It uses the energy from sodium ion gradients to transport glucose against its concentration gradient.
On the other hand, GLUT2 (Glucose Transporter Type 2) is primarily located on the basolateral membrane of enterocytes and provides a pathway for glucose to exit the cell and enter the bloodstream.
What makes the cytoplasme ?
Le contenu de la cellule (sauf le noyau)
Le cytosol + les organites
