PhysiologyZoology 203

Palomar Community CollegeDr. Kevin Krown

Office Hrs: during Lab

Email: kkrown@sunstroke.sdsu.edu

Phone: 619-594-7435

Cell Membrane Transport

• Intracellular (ICF)

• Extracellular (ECF)– Interstitial– Plasma

Body Fluid Compartments

Figure 5-13

• Energy requirements

• Physical requirements

Overview of Movement Across Membranes

Figure 5-14:

• Stops at equilibrium• Rate factors: membrane, temperature, distance, & size

Diffusion: Passive & down a concentration gradient

Figure 5-16:

• Uniport

• Cotransport– Symport– Antiport

Carrier Mediated Transport: Can be Passive or Active

Figure 5-17:

• Uses transport (integral) proteins • Passive Diffusion

Facilitated Diffusion

Figure 5- 21:

Facilitated Diffusion

Figure 5-22:

• Na-K ATPase

• Uses ATP to move products against a concentration gradient

Primary Active Transport: Pumps Products of the Cell

Figure 5-23:

Primary Active Transport:

Figure 5-24:

• Na-glucose symport• Cotransports • [Ion ] restored

– using ATP

Secondary Active Transport: Uses Energy of [ion] gradient

Figure 5-25:

• Cell metabolism

• Membrane transport

Energy Transfer in Cells

Figure 5-26:

• Endocytosis:• Phagocytosis: large particles (e.g. bacteria)• Pinocytosis: non-selective molecules • Receptor mediated: specific substrate

• Exocytosis:• Export of lipophobic substances (e.g. proteins)

Endocytosis and Exocytosis: Movement of large molecules

across membranes3 possible mechanisms:

Receptor-mediated Endocytosis (LDL Receptor)

Figure 5-28: