Cell transportation
TWO MAJOR TYPES OF TRANSPORT THROUGH BIOLOGICAL MEMBRANE
● Transport across biological membrane
• Transport across, but not through, membrane
1. Endocytosis
1.1. Phagocytosis : solid particle, “cell eating”1.2. Pinocytosis : soluble molecules “cell drinking”1.3. Receptor-mediated endocytosis
2. Exocytosis
Transport across, but not through, membrane
= Bulk transport
1.3. Receptor-medated endocytosis
SUTHILUK PATUMRAJ, Ph.D.Department of Physiology
Faculty of Medicine, Chulalongkorn University
LDL-c
2. ExocytosisExample:
Neurotransmitters;
acetylcholine (Ach)
SUTHILUK PATUMRAJ, Ph.D.Department of Physiology
Faculty of Medicine, Chulalongkorn University
active zone
trafficking
1. SIMPLE DIFFUSION
- osmosis : solvent
- diffusion : solute
2. CARRIER MEDIATED TRANSPORT
2.1 FACILITATED TRANSPORT
2.2 ACTIVE TRANSPORT
2.2.1 PRIMARY ACTIVE TRANSPORT
2.2.2 SECONDARY ACTIVE TRANSPORT
Transport across biological membrane
Membrane Transport of Small MoleculesMembrane Transport of Small Molecules
FICK FIRST LAW OF DIFFUSION
J = - D A dC / d X
D = DIFUSSION COEFFICIENT
A = AREA
dC = CONCENTRATION GRADIENT
dx = DISTANCE
Lipid solubilitysize
viscositytemperature
SIMPLE DIFFUSION
OSMOSISAbout 300 mlosmole/L
Hemolysis crenation
IONIC CHANNEL
GATING MECHANISMS
SELECTIVITY
CARRIER MEDIATED TRANSPORT
•SUTHILUK PATUMRAJ, Ph.D.
• Department of Physiology• Faculty of Medicine, Chulalongkorn University
Competition Molecules
X + Y
[C] ECF
[C]ICF
• GLUCOSE TRANSPORTER
• AMINO ACID TRANSPORTER
FACILITATED TRANSPORT
ACTIVE TRANSPORT
PRIMARY ACTIVE TRANSPORT
Na+ - K+ ATPase
K+ - H+ ATPase
Ca2+ - ATPase
SECONDARY ACTIVE TRANSPORT
CO-TRANSPORT
COUNTER-TRANSPORT
ATP
Na+
Energy source
•SUTHILUK PATUMRAJ, Ph.D.
• Department of Physiology• Faculty of Medicine, Chulalongkorn University
““HomeostasisHomeostasis””