Membranes Flashcards
Are sodium ions extracellular or intracellular?
Extracellular.
Are potassium ions extracellular or intracellular?
Intracellular
Can ions move across capillaires?
Yes.
What molecules can cross the cell membrane?
Oxygen and carbon dioxide.
What function of the cell membrane helps with the transmission of nerve impulses?
The fact that the permeability can increase/decrease at different times.
Membranes are dynamic. What does this mean?
It means they are continually being formed and maintained or dismantled and metabolized according to the needs of the cell.
What is the lipid bi-layer composed of?
Thin double layers of sheets of lipids.
What makes membranes flexible?
Fatty acids which behave like oil.
What can membrane carbs attach to and what are they called when they attach?
Lipids- glycolipid
Protein- glycoprotein.
What are intergral proteins?
Proteins which span the hydrophobic core of the lipid-bilayer/whole membrane.
What are peripheral proetins?
Only span one side of the cell membrane.
Name five functions of membrane proteins.
- Receptors
- Transport (transporter and channel proteins).
- Enzymes
- Maintenance of cell structure (anchorage).
- Commuinication.
Are receptors integral or peripheral to the membrane?
Integral.
What do receptors allow?
Communication of an extracellular chemical signal to the intracellular space to create a response.
Are transporters integral or peripheral?
Integral.
What do transporters allow?
Movement of ions or molecules across the membrane.
Name the two form of transporters.
Channels and transporters.
What do channel proteins do?
Create a pore in which molecules, like water and ions, can flow.
If a channel protein is open, which molecules can pass through?
Water.
If a channel is gated, which molecules can pass through?
Ions.
When are transporters open to ECF/ICF?
Open to ECF, then ICF, but never at the same time.
Which larger molecules can transporters tranposrt?
Glucose.
What do enzymes do?
Catalyse chemical reactions on the cell membrane.
Which side of the membrane can enzyme reactions take place?
Both! External/intrernal.