Foundations of Medicine Flashcards
(282 cards)
Describe the type of phospholipids on the outerleaflet of the membrane
Sphingomyelin & phosphatidylcholine
Describe a peripheral proteins vs an integral protein
Peripheral: Assoc. with cell membrane but are easily removed
Integral: Protruding from only one membrane surface or transmembrane-spanning throughout the membrane
What are the more common type of phospholipids found on the OUTER leaflet of the plasma membrane (applicable in RBC)
1.) Sphingomyelin (SM)
2.) Phosphatidylcholine (PC)
What are the more common type of phospholipids found on the INNER leaflet of the plasma membrane (applicable to RBC)
1.) phosphatidylserine (PS)
2.) Phosphatidylinositol (PI)
3.) phosphatidylethanolamine
THE COMPOSITION OF THE MEMBRANE LEAFLETS IS ACTIVELY Maintained BY A GROUP OF PROTEINS named:
Flippases and floppases
_____________ concentration is high in the plasma membrane compared to other cellular compartments
Cholesterol
Where is cholesterol synthesized in the cell?
ER
What are lipoproteins
round particles made of fat (lipids) and proteins that travel in your bloodstream to cells throughout your body. Cholesterol and triglycerides are two types of lipids found in lipoproteins.
Carbs occur on the outer membrane surface of the plasma membrane mainly as:
What is their purpose?
- glycoproteins and glycolipids
- Contribute to negative charge to membranes-immunity and barriers via repulsion
What is the purpose of the glycocalyx
Cell recognition
Adsorption of molecules on cell surface
Mechanical & chemical and protection
Glycoproteins can act as signaling molecules and can also:
Function as the surface receptors to which signaling molecules bind
G Protein coupled receptors are what type of protein
Integral protein
What is a peripheral protein
Anchored to only one side of the membrane
What type of protein is G-protein coupled receptor?
Integral protein
T/F: glycoproteins are only found in the cell membrane
False, some are found as hormones
T/F: Integral membranes may be transmembrane or anchored
True
Peripheral proteins are readily removed and compare to integral proteins. Give an example of each
They may be associated with integral proteins but are easily removed compared to integral proteins that require a detergent
I.e.
Integra: G protein coupled
Peripheral: G alpha subunit
Why does carrier mediated transport reach a saturation point while simple diffusion does not
Diffusion does not require any channel or carrier
All forms of carrier mediated transport share three features:
1.) Stereospecificity
2.) Saturation
3.) Competition
What feature of carrier mediated transport does this scenario represent: for some theraputics, single-enantiomer formulations can provide greater selectivity for their biological targets. Improved theraputid indices and/or better pharmacokinetics than a mixture of enatiomers
Competition
Varieties of molecules will act on one type of receptor with greater or lesser preference/concentration which indicates ______________ amongst these
Competition
What are the three major types of passive movement
What does Passive movement mean?
Simple
Facilitated diffusion
Osmosis
Movement from higher concentration to lower concentration
Channel mediated and carrier mediated diffusion are forms of _________________ ____________________ where movement of ions and molecules move down their concentration gradient known as:
Facilitated diffusion
Passive facilitated diffusion
How does channel mediated diffusion differ from carrier mediated?
Something has to bind and the carrier has to change conformation
Thus channels are faster at moving things inside our outside the cell