Physiology Exam 2 Notes

Physiology Exam 2 Notes - Physiology Exam 2 Notes: Membrane...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Physiology Exam 2 Notes: Membrane Transport: 1) Passive Transport: Concentration Gradient- Difference in conc. -Diffusion down conc. Gradient -No ATP Required (Higher → Lower Conc.) -Driving Force= Conc. Gradient- Car going down hill, no energy required 2) Active Transport: -Need ATP -Moving molecules from Lower → Higher Conc. -Diffusion up Conc. Gradient- Car going uphill, energy needed ● Hydrostatic Pressure: Pressure of water -Once osmotic and hydrostatic pressure are equal, no more net diffusion Fick’s Law’s of Diffusion: (Factors that Affect Diffusion Rate) Magnitude of Conc: ↑ Magnitude, ↑ Diffusion Permeability: ↑ Permeability, ↑ Diffusion Surface Area: ↑ Surface Area, ↑Diffusion Molecular Weight: ↓ Molecular Wt, ↑ Diffusion Distance: ↑ Distance, ↓ Diffusion Electrical Gradient: Diff in charge b/w 3 adjacent areas Electrochemical Gradient: Simultaneous existence of an electrical and chem. Gradient for an ion - Diffusion: Random collisions of molecules as a result of their continuous thermally induced charges. - Osmosis: Movement of water across a mem down its conc. Gradient toward the area of higher solute conc. Osmotic Pressure: Measure of the tendency for water to move into a solution b/c of its relative conc. of non-penetrating solutes and water. 3) Carrier Mediated Transport: Transport across the plasma membrane facilitated by a carrier molecule - A) Specificity: Each carrier protein is specialized to transport as specific substance -B) Saturation: Limited number of carrier binding sites available within a particular plasma membrane. Limit to the amount of a substance a carrier can transport. -C) Competition: Several compounds compete for a ride across the membrane Types of Carrier Mediated Transport: Facilitated Diffusion: Passive, involving transport of a substance down its conc. gradient across the plasma membrane. Active Transport: Active, involving transport of a substance against its conc. gradient across the membrane. Na+-K+ Pump: -Establishes NA+ and K+ conc gradients across membrane of all cells- Important in ability of nerve and muscle cells to generate electrical signals to function -Helps regulate cell volume by controlling the conc. of solutes inside the cell thus minimizing osmotic effects that induce swelling.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Endocytosis: Internalization of extracellular material w/in a cell as a result of the plasma forming a pouch that contains the extracellular material, then sealing at the surface of the pouch to form a small, intracellular, membrane-enclosed vesicle with the contents of the pouch trapped inside. Exocytosis: Fusion of a membrane-enclosed intracellular vesicle with the plasma membrane, followed by the opening of the vesicle and the emptying of its contents to the outside. -Provides mechanism for secreting large polar molecules
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/30/2008 for the course BIO 221 taught by Professor Van sciver during the Spring '08 term at Rhode Island.

Page1 / 10

Physiology Exam 2 Notes - Physiology Exam 2 Notes: Membrane...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online