PER 510- Physiology
Ch. 4 outline
The Plasma Membrane- recall the importance of the
plasma membrane in isolating internal cellular matrix (ICM)
from the external cellular matrix (ECM) = interstitium,
interstitial matrix, extracellular space
Structure:
Phospholipid bilayer- hydrophobic tails, hydrophilic heads
Forms spontaneously due to interaction with water
Majority/foundation of the barrier
Small and non-polar molecules move freely
Large and polar molecules cannot cross
Cholesterol- increases fluidity of molecular movements
“Fluid Mosaic Model”- increasing cholesterol will increase fluidity
*Glycolipids- cholesterol associated with carbohydrate chains
**Lipid rafts- concentrations of cholesterol and sphingolipids
Integral proteins- embedded within membrane (hydrophilic/hydrophobic interactions)
May be partial or complete thickness
Act as: Channels- create openings for diffusion of large and polar atoms or molecules
Receptors- respond to ligand by altering membrane permeability or cellular activities
~
Peripheral Proteins
Markers- identify cells within the body
-
↓ Chairs Bahain ,
&B Chan Neither = tipe O ,
Rh = D ,
not Rn= E
, ,
Transport- active transport of materials across the membrane
*Glycoproteins- associated with carbohydrate chains
Peripheral proteins- associated enzymes for metabolic activities
*Glycocalyx- important for development and immune system function
**Lipid rafts key to holding receptor proteins at particular position of cell surface (neurons)
**Lipid rafts create caveolae → inward folds which ↑ surface area = ↑ rate (smooth muscle)
Cellular transport mechanisms- how substances move across the membrane
Passive = no energy requirement, substances move from high concentrations to low concentrations
(with the concentration gradient)
Active = requires energy, substances move from low concentrations to high concentrations (against
the concentration gradient). Also, bulk movement of substances by means of vesicles.
Ch. 4 outline
The Plasma Membrane- recall the importance of the
plasma membrane in isolating internal cellular matrix (ICM)
from the external cellular matrix (ECM) = interstitium,
interstitial matrix, extracellular space
Structure:
Phospholipid bilayer- hydrophobic tails, hydrophilic heads
Forms spontaneously due to interaction with water
Majority/foundation of the barrier
Small and non-polar molecules move freely
Large and polar molecules cannot cross
Cholesterol- increases fluidity of molecular movements
“Fluid Mosaic Model”- increasing cholesterol will increase fluidity
*Glycolipids- cholesterol associated with carbohydrate chains
**Lipid rafts- concentrations of cholesterol and sphingolipids
Integral proteins- embedded within membrane (hydrophilic/hydrophobic interactions)
May be partial or complete thickness
Act as: Channels- create openings for diffusion of large and polar atoms or molecules
Receptors- respond to ligand by altering membrane permeability or cellular activities
~
Peripheral Proteins
Markers- identify cells within the body
-
↓ Chairs Bahain ,
&B Chan Neither = tipe O ,
Rh = D ,
not Rn= E
, ,
Transport- active transport of materials across the membrane
*Glycoproteins- associated with carbohydrate chains
Peripheral proteins- associated enzymes for metabolic activities
*Glycocalyx- important for development and immune system function
**Lipid rafts key to holding receptor proteins at particular position of cell surface (neurons)
**Lipid rafts create caveolae → inward folds which ↑ surface area = ↑ rate (smooth muscle)
Cellular transport mechanisms- how substances move across the membrane
Passive = no energy requirement, substances move from high concentrations to low concentrations
(with the concentration gradient)
Active = requires energy, substances move from low concentrations to high concentrations (against
the concentration gradient). Also, bulk movement of substances by means of vesicles.
