other modes of transport: facilitated diffusion and active transport campbell 5.17-5.21
TRANSCRIPT
Other Modes of Transport: Facilitated Diffusion and Active
Transport
Campbell 5.17-5.21
What are plasma membranes made of?
Membrane Structure• Made mostly of phospholipids• These form a phospholipid bilayer
Phosphate groupPolarHydrophilic Head
Fatty AcidNon-polarHydrophobic Tails
Large items and ions can’t cross membrane without gates!
Types of Membrane Transport
1. Simple Diffusion• Does NOT require energy• High to low concentration
2. Facilitated diffusion• Does NOT require energy• High to low concentration• A membrane protein is needed
3. Active transport • Requires energy• Low to high concentration• A membrane protein is needed
Passive Transport – No energy
Active Transport – requires energy
Passive transport
Types of Membrane Transport
Types of Transport Proteins•Non-specific transporter• Specific transporter
Aquaporins – facilitated diffusion- water is polar; won’t move on its own- aquaporin – pores that allow movement of water through channel protein
• Review protein structure
How glucose enters a cell- specific glucose transporter- facilitated diffusion – High to low – no energy!
What model of protein binding is this?
Active Transport – requires energy
Sodium-Potassium Pump
Bulk Transport – large amounts of substances cross the membrane
• Release to outside• Wastes, hormones,
signals
Endocytosis• Phagocytosis (eat)• Pinocytosis (drink)
Exocytosis
Animation
Ex. Phagocytosis
Video clip
part 3
Arteries transport blood away from the heart.
Veins transport blood towards the heart.
Capillaries transport gasses, nutrients, and waste into and out of the blood stream.
Show me what would happen if this is a capillary bed in the muscle tissues of a dehydrated person.
1. Exchange with cells or outside environment?
2. Nutrients, waste, O2, CO2, H2O?
Form suits function
Transport in the circulatory system
Circulatory system overview
Two hearts in one
Arteries
Capillaries (tissues)
Veins
Heart
Pulmonary circuit
Systemic circuit OxygenatedDeoxygenated
LV
RV
RA
LA
Capillaries (lungs)
ArteriesVeins
Human circulation
Alveoli are the site of gas exchange in the lungs.
Why so many?
